Infectious Disease Flashcards

Question

Which of the Plasmodium species can cause relapse

Answer 1

Merozoites invade RBCs to become trophozoites

Answer 2

Most West Africans and people with origins in that region are the Duffy-negative FyFy phenotype and are generally resistant to P. vivax malaria

Answer 3

Anopheles gambiae species complex in Africa, that are long-lived, occur in high densities in tropical climates, breed readily, and bite humans in preference to other animals.

Answer 4

vivax and ovale - young malariae- old

Answer 5

The geographic distributions of the thalassemias, sickle cell disease, hemoglobins C and E, hereditary ovalocytosis, and (G6PD) deficiency closely resemble that of falciparum malaria before the introduction of control measures. This similarity suggests that these genetic disorders confer protection against death from falciparum malaria Hemoglobin S–containing RBCs impair parasite growth at low oxygen tensions, and P. falciparum– infected RBCs containing hemoglobin S or C exhibit reduced cytoadherence because of reduced surface presentation of the adhesin PfEMP1

Answer 6

False preserved except in deep coma

Answer 7

Hypoglycemia, an important and common complication of severe malaria, is associated with a poor prognosis and is particularly problematic in children and pregnant women. Hypoglycemia in malaria results from both a failure of hepatic gluconeogenesis and an increase in the consumption of glucose by the host and, to a much lesser extent, the malaria parasites.

Answer 8

False there is no preerythrocytic stage of development, and thus there are no relapses of P. vivax and P. ovale infections

Answer 9

P. malariae

Answer 10

A. Young trophozoite. B. Old trophozoite. C. Trophozoites in erythrocytes and pigment in polymorphonuclear cells. D. Mature schizont. E. Female gametocyte. F. Male gametocyte

Answer 11

A. Young trophozoite. B. Old trophozoite. C. Mature schizont. D. Female gametocyte. E. Male gametocyte

Answer 12

A disadvantage of RDTs is that they do not quantify parasitemia

Answer 13

The World Health Organization (WHO) recommends artemisinin-based combination therapy (ACT) as first-line treatment for uncomplicated P. falciparum malaria in malaria-endemic areas

Answer 14

Artesunate therefore is now the drug of choice for all patients with severe malaria everywhere Severe falciparum malaria constitutes a medical emergency requiring intensive nursing care and careful management. Adjunctive treatments such as high-dose glucocorticoids, urea, heparin, dextran, desferrioxamine, antibody to tumor necrosis factor α, high-dose phenobarbital (20 mg/kg), mannitol, or large-volume fluid or albumin boluses have proved either ineffective or harmful in clinical trials and should not be used. In acute renal failure or severe metabolic acidosis, hemofiltration or hemodialysis should be started as early as possible

Answer 15

Need to add primaquine in addition to chloroquine or amodiaquine Primaquine eradicates hepatic forms of P. vivax and P. ovale; Note: primaquine should NOT be given in severe G6PD deficiency

Answer 16

When the patient is unconscious, the blood glucose level should be measured every 4–6 h. All patients should receive a continuous infusion of dextrose, and blood concentrations ideally should be maintained above 4 mmol/L. Hypoglycemia (<2.2 mmol/L or 40 mg/dL) should be treated immediately with bolus glucose. The parasite count and hematocrit should be measured every 6–12 h. It has been recommended that if the hematocrit falls to <20%, whole blood (preferably fresh) or packed cells should be transfused slowly, with careful attention to circulatory status.

Answer 17

Chloroquine

Answer 18

Amodiaquine

Answer 19

Pyrimethamine

Answer 20

kills all but fully mature gametocytes of P. falciparum. No action on liver stages

Answer 21

This syndrome is caused by increased pulmonary capillary permeability. Patients should be positioned with the head of the bed at a 45° elevation and should be given oxygen and IV diuretics. Positive-pressure ventilation should be started early if the immediate measures fail

Answer 22

An initial slow injection of 20% dextrose (2 mL/kg over 10 min) should be followed by an infusion of 10% dextrose (0.10 g/kg per hour). The blood glucose level should be checked regularly thereafter as recurrent hypoglycemia is common, particularly among patients receiving quinine

Answer 23

Patients who develop spontaneous bleeding should be given fresh blood and IV vitamin K.

Answer 24

Convulsions should be treated with IV or rectal benzodiazepines and, if necessary, respiratory support.

Answer 25

Mefloquine this drug is generally considered safe in the second and third trimesters of pregnancy;

Answer 26

Travelers to a malaria endemic region should start taking antimalarial drugs 2 days to 2 weeks before departure so that any untoward reactions can be detected before travel and so that therapeutic antimalarial blood concentrations will be present if and when any infections develop Antimalarial prophylaxis should continue for 4 weeks after the traveler has left the endemic area, except if atovaquone-proguanil or primaquine has been taken; these drugs have significant activities against the liver stage of the infection (causal prophylaxis) and can be discontinued 1 week after departure from the endemic area

Answer 27

severe renal impairment (creatinine clearance rate, <30 mL/min).

Answer 28

The growth of serotypes Salmonella Typhi and Salmonella Paratyphi is restricted to human hosts, in whom these organisms cause enteric (typhoid) fever.

Answer 29

True The infectious dose ranges from 200 colony-forming units (CFU) to 106 CFU, and the ingested dose is an important determinant of incubation period and disease severity

Answer 30

The mean incubation period for S. Typhi is 10–14 days but ranges from 5 to 21 days, depending on the inoculum size and the host’s health and vaccination status. The most prominent symptom is prolonged fever (38.8°–40.5°C [101.8°–104.9°F]), which can continue for up to 4 weeks if untreated

Answer 31

Rose spots make up a faint, salmon-colored, blanching, maculopapular rash located primarily on the trunk and chest. The rash is evident in ~30% of patients at the end of the first week and resolves without a trace after 2–5 days.

Answer 32

Gastrointestinal bleeding (6%) and intestinal perforation (1%) most commonly occur in the third and fourth weeks of illness and result from hyperplasia, ulceration, and necrosis of the ileocecal Peyer’s patches at the initial site of Salmonella infiltration

Answer 33

meningitis, Guillain-Barré syndrome, neuritis, and neuropsychiatric symptoms (described as “muttering delirium” or “coma vigil”), with picking at bedclothes or imaginary objects

Answer 34

Chronic carriage is more common among women, infants, and persons who have biliary abnormalities or concurrent bladder infection with Schistosoma haematobium Chronic carriage is associated with increased risk of GB cancer

Answer 35

The definitive diagnosis of enteric fever requires the isolation of S. Typhi or S. Paratyphi from blood, bone marrow, other sterile sites, rose spots, stool, or intestinal secretions. The diagnostic sensitivity of blood culture is only ~60% and is lower with low blood sample volume and among patients with prior antimicrobial use or in the first week of illness, reflecting the small number of S. Typhi organisms (i.e., <15/mL) typically present in the blood Bone marrow culture is >80% sensitive, and, unlike that of blood culture, its yield is NOT reduced by up to 5 days of prior antibiotic therapy Stool cultures, although negative in 60–70% of cases during the first week, can become positive during the third week of infection in untreated patients.

Answer 36

If drug susceptible, use FQ

Answer 37

Two typhoid vaccines are commercially available in the United States: (1) Ty21a, an oral live attenuated S. Typhi vaccine (given on days 1, 3, 5, and 7, with revaccination with a full four-dose series every 5 years); and (2) Vi CPS, a parenteral vaccine consisting of purified Vi polysaccharide from the bacterial capsule (given in a single dose, with a booster every 2 years)

Answer 38

chicken eggs

Answer 39

If uncomplicated, supportive only Because of increased resistance to conventional antibiotics such as ampicillin and TMP-SMX, extended-spectrum cephalosporins and fluoroquinolones have emerged as the agents of choice for the treatment of MDR NTS infections

Answer 40

Salmonella Choleraesuis and Salmonella Dublin

Answer 41

50% Echocardiography, CT, and indium-labeled white cell scanning are used to identify localized infection

Answer 42

Preemptive antibiotic treatment should be considered for patients at increased risk for invasive NTS infection, including neonates (probably up to 3 months of age); persons >50 years of age with known or suspected atherosclerosis; and patients with immunosuppression, cardiac valvular or endovascular abnormalities, or significant joint disease

Answer 43

If the patient has endocarditis or arteritis, treatment for 6 weeks with an IV β-lactam antibiotic (such as ceftriaxone or ampicillin) is indicated

Answer 44

Mosquitoes (predominantly Aedes aegypti, A. albopictus) Dengue virus is under flaviviruses

Answer 45

Viremia leads to multifocal entry into the CNS, presumably through infection of olfactory neuroepithelium, with passage through the cribriform plate, “Trojan horse” entry with infected macrophages, or infection of brain capillaries

Answer 46

Fever and myalgia syndrome Treatment is supportive, but acetylsalicylic acid is avoided because of the potential for exacerbated bleeding or Reye’s syndrome

Answer 47

dengue viruses 1–4

Answer 48

After dengue virus infection and an incubation period averaging 4–7 days, three evolving phases are described: a febrile phase, a critical phase, and a recovery phase.

Answer 49

A positive tourniquet test—i.e., the detection of 10 or more new petechiae in one square inch of the upper arm after a 5-min blood pressure cuff inflation to midway between systolic and diastolic pressure—may demonstrate microvascular fragility associated with dengue but is more likely to be associated with severe disease.

Answer 50

Near the time of defervescence on days 3–5, a maculopapular rash begins on the trunk and spreads to the extremities and the face.

Answer 51

dengue viruses 1–4 and yellow fever virus

Answer 52

A tetravalent live attenuated dengue vaccine based on the attenuated yellow fever virus 17D platform (CYD-TDV, or Dengvaxia) was licensed in 2015 and registered in 20 countries for individuals 9–45 years of age. However, retrospective analysis of phase 3 trials in Latin America and Asia suggested protection from severe dengue only in previously seropositive individuals; indeed, the risk of severe dengue was actually increased in seronegative vaccine recipients over that in nonvaccinated seronegative individuals, a result suggesting that a “first serologic hit” from the vaccine predisposes naïve recipients to more severe natural dengue infection.

Answer 53

presynaptic inhibitory nerves

Answer 54

Metronidazole (400 mg rectally or 500 mg IV every 6 h for 7 days) is preferred for antibiotic therapy. An alternative is penicillin (100,000–200,000 IU/ kg per day), although this drug theoretically may exacerbate spasms and in one study was associated with increased mortality

Answer 55

Antitoxin should be given early in an attempt to deactivate any circulating tetanus toxin and prevent its uptake into the nervous system. Two preparations are available: human tetanus immune globulin (TIG) and equine antitoxin. TIG is the preparation of choice, as it is less likely to be associated with anaphylactoid reactions. A single IM dose (500–5000 IU) is given, with a portion injected around the wound. Equine-derived antitoxin is available widely and is used in low-income countries; after hypersensitivity testing, 10,000–20,000 U is administered IM as a single dose or as divided doses.

Answer 56

0,1,6 months followed by one dose in subsequent pregnancies (or intervals of at least 1 year), to a total of five doses to provide long-term immunity.

Answer 57

proximal SMALL bowel

Answer 58

Giardiasis is diagnosed by detection of parasite antigens in the feces, by identification of cysts in the feces or of trophozoites in the feces or small intestines, or by nucleic acid amplification tests (NAATs). Cysts are oval, measure 8–12 μm × 7–10 μm, and characteristically contain four nuclei. Trophozoites are pear-shaped, dorsally convex, flattened parasites with two nuclei and four pairs of flagella

Answer 59

Cure rates with metronidazole (250 mg thrice daily for 5 days) are usually >90%. Tinidazole (2 g once by mouth) may be more effective than metronidazole. Nitazoxanide (500 mg twice daily for 3 days) is an alternative agent for treatment of giardiasis. Paromomycin, an oral aminoglycoside that is not well absorbed, can be given to symptomatic PREGNANT patients, although information is limited on how effectively this agent eradicates infection.

Answer 60

Many men infected with T. vaginalis are asymptomatic, although some develop urethritis and a few have epididymitis or prostatitis.

Answer 61

Detection of motile trichomonads by microscopic examination of wet mounts of vaginal or prostatic secretions has been the conventional means of diagnosis. Although this approach provides an immediate diagnosis, its sensitivity for the detection of T. vaginalis is only ~50–60% in routine evaluations of vaginal secretions. Direct immunofluorescent antibody staining is more sensitive (70–90%) than wet-mount examinations. T. vaginalis can be recovered from the urethra of both males and females and is detectable in males after prostatic massage. NAATs are FDA approved and are highly sensitive and specific for urine and for endocervical and vaginal swabs from women

Answer 62

Metronidazole (either a single 2-g dose or 500-mg doses twice daily for 7 days) or tinidazole (a single 2-g dose) is effective. Reinfection often accounts for apparent treatment failures, but strains of T. vaginalis exhibiting high-level resistance to metronidazole have been encountered. Treatment of these resistant infections with higher oral doses, parenteral doses, or concurrent oral and vaginal doses of metronidazole or with tinidazole has been successful. Sexual partners should also given metro 2g PO (single dose)

Answer 63

Individuals with acquired rubella may shed virus from 7 days before rash onset to ~5–7 days thereafter.

Answer 64

Laboratory assessment of rubella virus infection is conducted by serologic and virologic methods. For acquired rubella, serologic diagnosis is most common and depends on the demonstration of IgM antibodies in an acute-phase serum specimen or a fourfold rise in IgG antibody titer between acute- and convalescent-phase specimens. To detect a rise in IgG antibody titer indicative of acute disease, the acute phase serum specimen should be collected within 7–10 days after onset of illness and the convalescent-phase specimen ~14–21 days after the first specimen. The enzyme-linked immunosorbent assay IgM capture technique is considered most accurate for serologic diagnosis, but the indirect IgM assays also are acceptable. After rubella virus infection, IgM antibody may be detectable for up to 6 weeks. In case of a negative result for IgM in specimens taken earlier than day 5 after rash onset, serologic testing should be repeated.

Answer 65

The classic triad of CRS—clinical manifestations of cataracts, hearing impairment, and heart defects—is seen in ~10% of infants with CRS Hearing impairment is the most common single defect of CRS.

Answer 66

Administration of immunoglobulin should be considered only if a pregnant woman who has been exposed to a person with rubella will not consider termination of the pregnancy under any circumstances. In such cases, IM administration of 20 mL of immunoglobulin within 72 h of rubella exposure may reduce—but does not eliminate—the risk of rubella

Answer 67

vaccination with an RCV (Rubella containing Vaccine) One dose induces seroconversion in ≥95% of persons ≥1 year of age. Immunity is considered long-term and is probably lifelong. The most commonly used vaccine globally is the RA27/3 virus strain.

Answer 68

Because of the theoretical risk of transmission of live attenuated rubella vaccine virus to the developing fetus, women known to be pregnant should not receive RCV. In addition, pregnancy should be avoided for 28 days after receipt of RCV. In follow-up studies of ~3000 unknowingly pregnant women who received rubella vaccine, no infant was born with CRS. Receipt of RCV during pregnancy is not ordinarily a reason to consider termination of the pregnancy

Answer 69

usually involving the vasa vasorum of the ascending aorta and resulting in aneurysm);

Answer 70

single painless papule that rapidly erodes and becomes indurated, with a characteristic cartilaginous consistency on palpation of the edge and base of the ulcer.

Answer 71

usually located on the penis, where it is readily seen , but in MSM, it may also be found in the anal canal, rectum, or mouth. In women, common primary sites are the cervix, vaginal wall, and labia, as well as anal canal and mouth. Consequently, primary syphilis goes unrecognized in women and MSM more often than in heterosexual men.

Answer 72

mucocutaneous or cutaneous lesions and generalized nontender lymphadenopathy Rarely, severe necrotic lesions (lues maligna) may appear and are more commonly reported in HIV-infected individuals.

Answer 73

Positive serologic tests for syphilis, together with a normal CSF examination and the absence of clinical manifestations of syphilis, indicate a diagnosis of latent syphilis in an untreated person.

Answer 74

Early latent syphilis is limited to the first year after infection, whereas late latent syphilis is defined as that of ≥1 year’s (or unknown) duration. The classical definition of early latent syphilis would include a person whose secondary rash has resolved, as well as a person whose chancre has healed but who has not yet developed secondary manifestations.

Answer 75

1:32 While most experts agree that neurosyphilis is more common among persons with untreated HIV infection, the immune reconstitution seen with effective ART may have a protective effect against development of clinical neurosyphilis in HIV-infected persons with syphilis

Answer 76

The most common presentation is a strokes yndrome involving the middle cerebral artery of a relatively young adult.

Answer 77

Tabes dorsalis

Answer 78

The RPR test is easier to perform and uses unheated serum or plasma; it is the test of choice for rapid serologic diagnosis in a clinical setting.

Answer 79

The VDRL test remains the standard for examining CSF and is superior to the RPR for this purpose. The CSF VDRL test is highly specific and, when reactive, is considered diagnostic of neurosyphilis; however, this test is insensitive and may be nonreactive even in cases of symptomatic neurosyphilis. VDRL -Very good for the Vrain

Answer 80

Involvement of the CNS is detected by examination of CSF for mononuclear pleocytosis (>5 white blood cells/μL), increased protein concentration (>45 mg/dL), or CSF VDRL reactivity

Answer 81

Penicillin G

Answer 82

For penicillin-allergic patients with syphilis, a 2-week (early syphilis) or 4-week (late or late latent syphilis) course of therapy with doxycycline or tetracycline is recommended Doxycycline (100 mg PO bid) or tetracycline HCl (500 mg PO qid) for 2 weeks

Answer 83

NONE Desensitize and treat with penicillin

Answer 84

Administration of either IV aqueous crystalline penicillin G or of IM aqueous procaine penicillin G plus oral probenecid in recommended doses is thought to ensure treponemicidal concentrations of penicillin G in CSF

Answer 85

Penicillin is the only recommended agent for the treatment of syphilis in pregnancy. If the patient has a documented penicillin allergy, desensitization and penicillin therapy should be undertaken

Answer 86

JARISCH-HERXHEIMER REACTION The Jarisch-Herxheimer reaction occurs in ~50% of patients with primary syphilis, 90% of those with secondary syphilis, and a lower proportion of persons with later-stage disease.

Answer 87

Patients with primary or secondary syphilis should be examined 6 and 12 months after treatment, and persons with latent or late syphilis at 6, 12, and 24 months. More frequent clinical and serologic examination (3, 6, 9, 12, and 24 months) is recommended for patients concurrently infected with HIV, regardless of the stage of syphilis

Answer 88

Efficacy of treatment should be assessed by clinical evaluation and monitoring of the quantitative VDRL or RPR titer for a fourfold decline (e.g., from 1:32 to 1:8). Because treponemal tests may remain reactive despite treatment for seropositive syphilis, these tests are not useful in following the response to therapy.

Answer 89

Acute urethritis is the most common clinical manifestation of gonorrhea in male patients. The usual incubation period after exposure is 2–7 days, although the interval can be longer and most men remain asymptomatic.

Answer 90

C. trachomatis Urethral infection with N. gonorrhoeae also may occur in this context, but in this instance, urethral cultures are usually positive

Answer 91

Skin lesions are seen in ~75% of patients and include papules and pustules, often with a hemorrhagic component

Answer 92

Suppurative arthritis involves one or two joints, most often the knees, wrists, ankles, and elbows (in decreasing order of frequency); other joints occasionally are involved.

Answer 93

No. Only in men The detection of gram-negative intracellular monococci and diplococci is usually highly specific and sensitive in diagnosing gonococcal urethritis in symptomatic males but is only ~50% sensitive in diagnosing gonococcal cervicitis.

Answer 94

The third-generation cephalosporin ceftriaxone is now recommended as the first-line regimen for use at twice the previous dose (now, 500 mg IM, single dose) based on doubling of mean inhibitory concentrations (MICs) of current strains compared with MICs 20 years ago Azithromycin, which had been recommended to provide additional treatment of gonorrhea (also to include treatment of chlamydial infection) is NO longer recommended as part of a first line regimen

Answer 95

If chlamydial infection cannot be excluded, concurrent treatment with doxycycline (100 mg orally twice a day for 7 days) is recommended

Answer 96

None Persons with uncomplicated genital or rectal infections who receive ceftriaxone or an alternative regimen do not need a test of cure; however, cultures for N. gonorrhoeae should be performed if symptoms persist after therapy with an established regimen, and any gonococci isolated should be tested for antimicrobial susceptibility.

Answer 97

Gonococcal meningitis and endocarditis should be treated in the hospital with high-dose IV ceftriaxone (1–2 g IV every 12–24 h); therapy should continue for 10–14 days for meningitis and for at least 4 weeks for endocarditis

Answer 98

complement deficiency.

Answer 99

60 days If the patient’s last potential sexual exposure to infection was >60 days before onset of symptoms or diagnosis, the patient’s most recent sex partner should be treated

Answer 100

True as this test is 98% sensitive for the diagnosis of gonococcal urethral infection.

Answer 101

C. trachomatis and less commonly by N. gonorrhoeae and is usually associated with overt or subclinical urethritis.

Answer 102

metronidazole

Answer 103

NAAT for T. vaginalis is more sensitive than culture.

Answer 104

Trichomoniasis

Answer 105

bacterial vaginosis assoc with Gardnerella vaginalis

Answer 106

Azole cream, tablet, or suppository—e.g., miconazole (100-mg vaginal suppository) or clotrimazole (100-mg vaginal tablet) once daily for 7 days OR Fluconazole, 150 mg orally (single dose)

Answer 107

Examination for sexually transmitted infection; treatment with metronidazole, 2 g PO (single dose)

Answer 108

Bacterial vaginosis

Answer 109

BV is conventionally diagnosed clinically with the Amsel criteria, which include any three of the following four clinical abnormalities: (1) objective signs of increased white homogeneous vaginal discharge; (2) a vaginal discharge pH of >4.5; (3) liberation of a distinct fishy odor (attributable to volatile amines such as trimethylamine) immediately after vaginal secretions are mixed with a 10% solution of KOH; and (4) microscopic demonstration of “clue cells”

Answer 110

>Metronidazole, 500 mg PO bid for 7 days >Metronidazole gel, 0.75%, one applicator (5 g) intravaginally once daily for 5 days > Clindamycin, 2% cream, one full applicator vaginally each night for 7 days

Answer 111

Although the antimicrobial susceptibility of M. genitalium is not yet well defined, the organism frequently persists after doxycycline therapy, and it currently seems reasonable to use azithromycin to treat possible M. genitalium infection in such cases. With resistance of M. genitalium to azithromycin now recognized, moxifloxacin may be a reasonable alternative.

Answer 112

C. trachomatis

Answer 113

Perihepatitis/ Fitz-Hugh–Curtis syndrome Pleuritic upper abdominal pain and tenderness, usually localized to the right upper quadrant (RUQ), develop in 3–10% of women with acute PID

Answer 114

Hospitalized patients should show substantial clinical improvement within 3–5 days. Women treated as outpatients should be clinically reevaluated within 72 h.

Answer 115

Surgery is necessary for the treatment of salpingitis only in the face of life-threatening infection (such as rupture or threatened rupture of a tuboovarian abscess) or for drainage of an abscess. Conservative surgical procedures are usually sufficient. Pelvic abscesses can often be drained by posterior colpotomy, and peritoneal lavage can be used for generalized peritonitis.

Answer 116

PCR testing of genital ulcers now clearly implicates genital herpes as by far the most common cause of genital ulceration in most developing countries.

Answer 117

True Clinicians should order a rapid serologic test for syphilis in all cases of genital ulcer and treat presumptively while awaiting serology in a patient at high risk (especially MSM)

Answer 118

herpes These typical clinical manifestations make detection of the virus optional; however, many patients want confirmation of the diagnosis, and differentiation of HSV-1 from HSV-2 has prognostic implications, because the latter causes more frequent genital recurrences and is more infectious to vulnerable sex partners.

Answer 119

primary syphilis.

Answer 120

ulcers are painful and purulent, especially if inguinal lymphadenopathy with fluctuance or overlying erythema is noted;

Answer 121

in addition to the usual tests for herpes, syphilis, and chancroid—biopsy is indicated to exclude donovanosis as well as carcinoma and other nonvenereal dermatoses.

Answer 122

Herpes and Chancroid

Answer 123

Donovanosis

Answer 124

Donovanosis

Answer 125

Chancroid and Donovanosis B-C-D Bleed-chancroid-donovanosis

Answer 126

Acquisition of HSV, N. gonorrhoeae, or C. trachomatis (including LGV strains of C. trachomatis) during receptive anorectal intercourse causes most cases of infectious proctitis in women and MSM.

Answer 127

most distal rectal mucosa and the anal crypts

Answer 128

In contrast, primary proctitis due to HSV and proctocolitis due to the strains of C. trachomatis that cause LGV usually produce severe anorectal pain and often cause fever

Answer 129

In MSM without HIV infection, enteritis is often attributable to Giardia lamblia.

Answer 130

Sexually acquired proctocolitis is most often due to Campylobacter or Shigella species.

Answer 131

Pending test results, patients with proctitis should receive empirical syndromic treatment—e.g., with ceftriaxone (a single IM dose of 500 mg for gonorrhea) plus doxycycline (100 mg by mouth twice daily for 7 days for possible chlamydial infection) plus treatment for herpes or syphilis if indicated. If LGV proctitis is proven or suspected, the recommended treatment is doxycycline (100 mg by mouth twice daily for 21 days); alternatively, 1 g of azithromycin once a week for 3 weeks is likely to be effective but is little studied.

Answer 132

Pthirus pubis and Sarcoptes scabiei infestations

Answer 133

25 In women 25–29 years of age, chlamydial infection is uncommon but still may reach a prevalence of 3–5% in some settings;

Answer 134

The optimal age for recommended vaccination is 11–12 years because of the very high risk of HPV infection after sexual debut.

Answer 135

Trachoma serovars A, B, Ba, and C the oculogenital serovars D–K and the LGV serovars L1–L3.

Answer 136

Elementary body, which is the infectious form and is specifically adapted for Extracellular survival, and the metabolically active and Replicating Reticulate body, which is not infectious, is adapted for an intracellular environment, and does not survive well outside the host cell. E-E-nfectious R- Replicating

Answer 137

LGV Donovanosis -PSEUDObuboes

Answer 138

The designation PGU refers to NGU developing in men 2–3 weeks after treatment of gonococcal urethritis with single doses of agents such as penicillin or cephalosporins, which lack antimicrobial activity against chlamydiae.

Answer 139

Reactive arthritis consists of conjunctivitis, urethritis (or, in female patients, cervicitis), arthritis, and characteristic mucocutaneous lesions.

Answer 140

14 Arthritis usually begins ~4 weeks after the onset of urethritis but may develop sooner or, in a small percentage of cases, may actually precede urethritis

Answer 141

30 Although 20 lang to dx endocervicitis

Answer 142

C. trachomatis

Answer 143

The first nonculture assays, such as direct fluorescent antibody staining of clinical material and enzyme immunoassay (EIA), have been replaced by NAATs, which are currently recommended by the CDC as the diagnostic assays of choice.

Answer 144

For screening of asymptomatic women, the CDC now recommends that self-collected or clinician-collected vaginal swabs, which are slightly more sensitive than urine, be used.

Answer 145

For symptomatic women undergoing a pelvic examination, cervical swab samples are desirable because they have slightly higher chlamydial counts. For male patients, a urine specimen is the sample of choice, but self-collected penile-meatal swabs have been shown to be very effective.

Answer 146

LGV CF titer, ≥1:64; MIF titer, ≥1:512

Answer 147

Residual nucleic acid from cells rendered noninfective by antibiotics may continue to yield a positive result in NAATs for as long as 3 weeks after therapy when viable organisms have actually been eradicated. Therefore, clinicians should not use NAATs for test of cure until after 3 weeks.

Answer 148

The CDC currently does not recommend a test of cure after treatment for infection with C. trachomatis. However, because incidence studies have demonstrated that previous chlamydial infection increases the probability of becoming reinfected, the CDC does recommend that previously infected individuals be rescreened 3 months after treatment.

Answer 149

The serologic test of choice is the microimmunofluorescence (MIF) test

Answer 150

A 7-day course of oral doxycycline (100 mg twice daily) or a single 1-g oral dose of azithromycin are the primary recommended regimens of treatment for uncomplicated chlamydial infections. Alternative 7-day oral regimens include erythromycin (500 mg four times daily), or a fluoroquinolone (ofloxacin, 300 mg twice daily; or levofloxacin, 500 mg/d) can be used. The single 1-g oral dose of azithromycin is as effective as a 7-day course of doxycycline for the treatment of uncomplicated genital C. trachomatis infections in adults

Answer 151

The clinical diagnosis of classic trachoma can be made if two of the following signs are present: (1) lymphoid follicles on the upper tarsal conjunctiva; (2) typical conjunctival scarring; (3) vascular pannus; or (4) limbal follicles or their sequelae, Herbert pits.

Answer 152

On slit-skin smear examination at the lepromatous end of the disease spectrum, M. leprae is predominantly found in clumps or globi within macrophages (lepra cells).

Answer 153

The temperature required for survival and proliferation—between 27°C and 30°C—explains the greater impact of the disease on surface areas such as the skin, peripheral nerves, testicles, and upper airways, with less inner visceral involvement.

Answer 154

It is assumed that humans are the main reservoir of infection for M. leprae. The armadillo is also a reservoir for human infection.

Answer 155

2 to ≥10 years.

Answer 156

Poverty-associated factors such as low level of education, poor hygiene, and food shortages have been identified as risk factors for leprosy, but the most important risk factors are associated with intimacy and duration of contact with a leprosy patient, in particular with an index case with multibacillary leprosy, and the intensity of contact with and physical distance from the index patient.

Answer 157

Indeterminate Leprosy (IL)

Answer 158

TT leprosy On slit-skin smear examination, no acid-fast bacilli (AFB) are normally found. The lepromin skin test is strongly positive, signifying good host CMI status.

Answer 159

Lepromatous leprosy clue: symmetric lesions, lion face

Answer 160

The nose is the portal of entry for M. leprae and is the earliest site of involvement in LL leprosy.

Answer 161

Histoid leprosy

Answer 162

Diffuse leprosy of Lucio and Latapi

Answer 163

Lucio phenomenon

Answer 164

Three cardinal signs indicate a diagnosis of leprosy. The diagnosis can be established when two of these three signs are present: 1. Hypopigmented or erythematous skin lesion(s) with definite loss or impairment of sensation 2. Involvement of the peripheral nerves, as demonstrated by definite thickening with sensory impairment peripheral nerves commonly palpated in a leprosy patient are the greater auricular, ulnar, radial, radial cutaneous, median, lateral popliteal, posterior tibial, sural, and superficial peroneal nerves. 3. A positive result for AFB in slit-skin smears, establishment of the presence of AFB in a skin smear or biopsy sample, or a positive result in a biopsy PCR.

Answer 165

the right earlobe, the forehead above the eyebrows, the chin, and the left buttock in men or the left upper thigh in women.

Answer 166

PGL-1 ELISA

Answer 167

LL or BL leprosy, indicating the lack of a protective cellular response.

Answer 168

The ulnar and median nerves and the posterior tibial nerve are usually tested for touch sensation. The most reliable test is the Semmes-Weinstein monofilament (SWM) test.

Answer 169

“DDS syndrome” (also called the dapsone hypersensitivity syndrome) is a severe adverse event that is not uncommon in some countries. It usually develops 6 weeks after the commencement of dapsone administration and manifests as fever, skin rash, eosinophilia, lymphadenopathy, hepatitis, and encephalopathy.

Answer 170

The most noticeable adverse event is skin discoloration ranging from red to purple or black, with the degree of discoloration depending on the dosage The abnormal pigmentation usually fades within 6–12 months of clofazimine discontinuation, although traces of discoloration may remain for up to 4 years.

Answer 171

For rifampin-resistant leprosy, the WHO guidelines recommend daily treatment with at least two second-line drugs—clarithromycin, minocycline, or a quinolone (ofloxacin, levofloxacin, or moxifloxacin)—plus clofazimine for 6 months, followed by clofazimine plus one of the second-line drugs daily for an additional 18 months. Leprosy patients infected with M. leprae resistant to both rifampin and ofloxacin may be treated daily with the following regimen: clarithromycin, minocycline, and clofazimine for 6 months, followed by clarithromycin or minocycline plus clofazimine for an additional 18 months.

Answer 172

A large randomized controlled trial has shown that single-dose rifampin, given once to household contacts, neighbors, and social contacts, reduces the recipients’ risk of leprosy by ~60%.

Answer 173

Oral, short-acting glucocorticoids are the treatment of choice for T1R. Prednisolone is used most often in an initial dose of 1 mg/kg of body weight once a day, usually with a maximum of 60–80 mg The dose is tapered slowly, usually by 5 mg every 2 weeks over a period of 20 weeks—a schedule that results in better outcomes and lower reaction relapse rates than the previously recommended 12-week glucocorticoid regimen. Patients should be examined every 2 weeks, and the examination should include a quick nerve function assessment.

Answer 174

Mild first-time T2R (or ENL) reactions with localized skin nodules may be treated with aspirin and pentoxifylline. If a rapid effect is needed, the most effective drug to date is thalidomide, which rapidly suppresses clinical signs, including nerve impairment and iritis. A dose of 100–200 mg is given either once or twice daily. In patients with severe recurrent ENL, a daily thalidomide maintenance dose of 50 mg may be effective in suppressing new episodes. High-dose clofazimine also is effective in preventing recurrent ENL, but attainment of a maximal effect takes several weeks.

Answer 175

Generally, for the treatment of neuropathic pain, three classes of medication are available: tricyclic antidepressants, phenothiazines, and anticonvulsants (carbamazepine, oxcarbazepine, gabapentin, and pregabalin).

Answer 176

K. pneumoniae

Answer 177

Viridans streptococci if hospital acquired: S. aureus

Answer 178

Until neutropenia resolves (>500)

Answer 179

Benzathine Pen G 1.2 mU or Pen V 250 mg TID or 500 mg BID x 10 days

Answer 180

S. japonicum

Answer 181

Diethylcarbamazine

Answer 182

pulmonary infection

Answer 183

Before touching a patient Before clean or aseptic procedures After exposure to bodily fluids or risk of exposure After touching a patient After touching a patient's surrounding

Answer 184

Airborne but if Influenza A and B --> droplet

Answer 185

Ethionamide

Answer 186

tetracycline

Answer 187

Impetigo contagiosa is caused by S. pyogenes, and bullous impetigo is due to S. aureus.

Answer 188

True PSGN is a complication but not rheumatic fever (molecular mimicry)

Answer 189

Pseudomonas aeruginosa

Answer 190

Bartonella bacilliformis

Answer 191

S. pyogenes Flaccid bullae may develop during the second or third day of illness, but extension to deeper soft tissues is rare.

Answer 192

Erysipelothrix rhusiopathiae remains susceptible to most β-lactam antibiotics (including penicillin), erythromycin, clindamycin, tetracycline, and cephalosporins but is resistant to sulfonamides, chloramphenicol, and vancomycin. Its resistance to vancomycin, which is unusual among gram-positive bacteria, is of potential clinical significance since this agent is sometimes used in empirical therapy for skin infection.

Answer 193

Panton-Valentine leukocidin (PVL) toxin

Answer 194

Same Pen G + Clinda but if necrotizing fascitis is caused by mixed aerobes and anaeroebs = Ampisul+ clinda + cipro

Answer 195

HPV and HBV

Answer 196

Contraindications: Serogroup B meningococcal, Hep A and B Precaution only: Td, Tdap

Answer 197

MMR and Varicella

Answer 198

refrigerator freezer

Answer 199

oral typhoid

Answer 200

15 minThe ACIP recommends that vaccine providers strongly consider observing patients, particularly adolescents, with patients seated or lying down for 15 min after vaccination. If syncope develops, patients should be observed until the symptoms resolve

Answer 201

vegetation

Answer 202

β-Hemolytic streptococci, S. aureus, and pneumococci typically result in an acute course, although S. aureus occasionally causes subacute disease. IE caused by Staphylococcus lugdunensis (a coagulase-negative species) or by enterococci may present acutely. In patients with subacute presentations, fever is typically low-grade rarely exceeding 39.4°C (103°F); in contrast, temperatures of 39.4°– 40°C (103°–104°F) are often noted in acute IE.

Answer 203

Subacute IE is typically caused by viridans streptococci, enterococci, CoNS, and the HACEK group. In patients with subacute presentations, fever is typically low-grade rarely exceeding 39.4°C (103°F); in contrast, temperatures of 39.4°– 40°C (103°–104°F) are often noted in acute IE.

Answer 204

IE caused by Bartonella species, T. whipplei, C. burnetii, or M. chimaera is exceptionally indolent.

Answer 205

S. aureus IE, mobile vegetations >10 mm in diameter, and infection involving the mitral valve anterior leaflet are independently associated with an increased risk of embolization. Arterial emboli, one-half of which precede the diagnosis of IE, are clinically apparent in up to 50% of patients.

Answer 206

A clinical diagnosis of definite IE requires documentation of two major criteria, of one major and three minor criteria, or of five minor criteria.

Answer 207

Consider CTA or FDG-PET/CT^

Answer 208

Transfuse pRBC since with decreasing hct. Look for signs of bleeding. May also consider whole blood for unstable px

Answer 209

up to 28 days if MSSA up to 21 days

Answer 210

10-14 days

Answer 211

14-21 days

Answer 212

True by aspiration of oropharyngeal contents in the lower respiratory tract

Answer 213

> 5 mmol/L

Answer 214

E. faecium

Answer 215

Although it is FDA approved only for right-sided IE at a dose of 6 mg/kg daily, most recommend doses of 8–10 mg/kg daily for treatment of left-sided IE.

Answer 216

Pending the availability of diagnostic data, blood culture–negative subacute NVE is treated with vancomycin plus ampicillin-sulbactam (12 g every 24 h) or ceftriaxone; doxycycline (100 mg twice daily) is added for enhanced Bartonella coverage. If cultures are negative because of prior antibiotic administration, pathogens likely to be inhibited by the specific prior therapy should be considered.

Answer 217

Control of peripheral sites of infection—source control—should be addressed promptly. Blood cultures should be repeated daily until sterile in patients with IE due to S. aureus or difficult-to-treat organisms, rechecked if there is recrudescent fever, and performed again 4–6 weeks after therapy to document cure.

Answer 218

Blood cultures become sterile after 2 days of appropriate therapy when infection is caused by viridans streptococci, E. faecalis, or HACEK organisms. In MSSA IE, β-lactam therapy results in sterile cultures in 3–5 days, whereas in MRSA IE, the duration of bacteremia is often longer with vancomycin or daptomycin treatment.

Answer 219

septal perforation is urgent only

Answer 220

TEE with color Doppler is the test of choice to detect paravalvular abscesses (sensitivity, ≥85%).

Answer 221

2–3 weeks 4 weeks

Answer 222

>=2 episodes in 6 mos; >=3 in 12 mos

Answer 223

SSx + chext xray suggestive of PTB

Answer 224

Symptom screening + CXR

Answer 225

1 for Gene Xpert:on the spot 2 for sputum microscopy: on the spot + 1 hr after or early AM the following day

Answer 226

apical and posterior segment of the upper lobe, superior segment of the lower lobe APU SS

Answer 227

Adult: lower thoracic and upper lumbar Childern: Upper thoracic

Answer 228

In px with shock/ Obtundation

Answer 229

2 Females are more commonly affected than males

Answer 230

False Severe hepatocellular necrosis is not a feature of leptospirosis

Answer 231

2nd most common cause of death: pulmo complications

Answer 232

>35 and 70

Answer 233

hypoglycemia

Answer 234

False malnutrition - protective female sex- risk factor

Answer 235

1-2 weeks before travelling, once a week on the same day of the week and for 4 weeks upon return Same with other -quine except primaquine (1-2 days , daily, 7 days after return)

Answer 236

Gray hepatization

Answer 237

Exclude possibility of malignancy after CAP

Answer 238

CRO 2g IV OD

Answer 239

28 days of Cipro

Answer 240

Leukopenia

Answer 241

Ethambutol E for adjustment based on EGFR

Answer 242

1-4 mL for all specimen except CSF 0.5-4 mL

Answer 243

True as per IDSA guidelines

Answer 244

S. aureus P. aeruginosa G- bacilli VAP--> SPG

Answer 245

Procalcitonin CPIS not suggested

Answer 246

Aztreonam + FQ

Answer 247

three doses 1 month apart then 2 boosters 6 months apart if with primary course, 2 doses only 1 month apart

Answer 248

3 doses of full primary course of immunization since natural infection is poorly immunogenic

Answer 249

False. Only glucocorticoids Remdeivir- no improvement in 30-day survival rate

Answer 250

Skin lesion fluid or crusts

Answer 251

2nd month. If positive by end of 2nd month, test also 5th and 6th bacteriologically confirmed automatic 2,5,6

Answer 252

N. meningitides

Answer 253

S. pneumoniae

Answer 254

P. aeruginosa

Answer 255

bronchopneumonia

Answer 256

Aspiration most common etiology: polymicrobial

Answer 257

The first symptom of spontaneous gas gangrene may be confusion followed by the abrupt onset of excruciating pain in the absence of trauma. These findings, along with fever, should heighten suspicion of spontaneous gas gangrene. However, because of the lack of an obvious portal of entry, the correct diagnosis is frequently delayed or missed.

Answer 258

It is important to recognize that, for C. perfringens and C. novyi, trauma must be sufficient to interrupt the blood supply and thereby to establish an optimal anaerobic environment for growth of these species. These conditions are not strictly required for the more aerotolerant species such as C. septicum and C. tertium, which can seed normal tissues from gastrointestinal lesions.

Answer 259

Alpha toxin

Answer 260

True Mortality rates are relatively high among patients with spontaneous gas gangrene, especially that due to C. septicum

Answer 261

Except for infection caused by C. tertium (see below), antibiotic treatment of traumatic or spontaneous gas gangrene consists of the administration of penicillin and clindamycin for 10–14 days. C. tertium is resistant to penicillin, cephalosporins, and clindamycin. Appropriate antibiotic therapy for C. tertium infection is vancomycin (1 g every 12 h IV) or metronidazole (500 mg every 8 h IV).

Answer 262

centripetally toward CNS Centrifugal spread along nerves to salivary glands, skin, cornea, and other organs

Answer 263

The earliest specific neurologic symptoms of rabies include paresthesias, pain, or pruritus near the site of the exposure, one or more of which occur in 50–80% of patients and strongly suggest rabies.

Answer 264

Diagnostically useful specimens include serum, CSF, fresh saliva, skin biopsy samples from the neck, and brain tissue (rarely obtained before death). Corneal impression smears are of low diagnostic yield and are generally not performed

Answer 265

There is no established treatment for rabies. Aggressive management with supportive care in critical care units has resulted in the survival of at least 30 patients with rabies. Many of these survivors have recently been reported from India. There have been many recent treatment failures (more than 55) with the combination of antiviral drugs, ketamine, and therapeutic (induced) coma—measures that were used in a healthy survivor in whom neutralizing antibodies to rabies virus were detected at presentation. Expert opinion is recommended before a course of experimental therapy is embarked upon. A palliative approach may be appropriate for many patients who are not considered candidates for aggressive management

Answer 266

RIG and vaccine If RIG is not immediately available, it should be administered no later than 7 days after the first vaccine dose. After day 7, endogenous antibodies are being produced, and passive immunization may actually be counterproductive.

Answer 267

Four 1-mL doses of rabies vaccine should be given IM in the deltoid area. (The anterolateral aspect of the thigh also is acceptable in children.) Gluteal injections, which may not always reach muscle, should not be given and have been associated with rare vaccine failures

Answer 268

0,3,7,14 Ideally, the first dose should be given as soon as possible after exposure; failing that, it should be given without further delay. The three additional doses should be given on days 3, 7, and 14; a fifth dose on day 28 is no longer recommended

Answer 269

If human RIG is unavailable, purified equine RIG can be used in the same manner at a dose of 40 IU/kg

Answer 270

If anatomically feasible, the entire dose of RIG (20 IU/kg) should be infiltrated at the site of the bite, and any RIG remaining after infiltration of the bite site should be administered IM at a distant site. Only given for previously UNvaccinated

Answer 271

Preexposure rabies prophylaxis should be considered for people with an occupational or recreational risk of rabies exposures and also for certain travelers to rabies-endemic areas. The primary schedule consists of three doses of rabies vaccine given on days 0, 7, and 21 or 28. Serum neutralizing antibody tests help determine the need for subsequent booster doses. When a previously immunized individual is exposed to rabies, two booster doses of vaccine should be administered on days 0 and 3. Wound care remains essential. As stated above, RIG should not be administered to previously vaccinated persons.

Answer 272

Acute cystitis

Answer 273

True increased relative risk ranging from 1.4 with one episode of intercourse in the preceding week to 4.8 with five episodes.

Answer 274

frequent sexual intercourse and spermicide use.

Answer 275

E. coli E. coli accounts for 75–90% of isolates; Staphylococcus saprophyticus for 5–15% (with particularly frequent isolation from younger women); and Klebsiella, Proteus, Enterococcus, and Citrobacter species, along with other organisms, for 5–10%

Answer 276

True However, hematogenous spread accounts for <2% of documented UTIs and usually results from bacteremia caused by relatively virulent organisms, such as Salmonella and S. aureus The pathogenesis of candiduria is distinct in that the hematogenous route is common. The presence of Candida in the urine of a non-instrumented immunocompetent patient implies either genital contamination or potentially widespread visceral dissemination.

Answer 277

Colonization of the vaginal introitus and periurethral area with organisms from the intestinal flora (usually E. coli) is the critical initial step in the pathogenesis of UTI

Answer 278

Fever is the main feature distinguishing cystitis from pyelonephritis. The fever of pyelonephritis typically exhibits a high spiking “picket-fence” pattern and resolves over 72 h of therapy.

Answer 279

moxifloxacin

Answer 280

High rates of TMP-SMX-resistant E. coli in patients with pyelonephritis have made fluoroquinolones the first-line therapy for acute uncomplicated pyelonephritis.

Answer 281

Nitrofurantoin, ampicillin, and the cephalosporins are considered relatively safe in early pregnancy Ampicillin and the cephalosporins have been used extensively in pregnancy and are the drugs of choice for the treatment of asymptomatic or symptomatic UTI in this group of patients. ASB are treated for 4–7 days in the absence of evidence to support single-dose therapy.

Answer 282

If acute bacterial prostatitis is suspected, antimicrobial therapy should be initiated after urine and blood are obtained for cultures. Therapy can be tailored to urine culture results and should be continued for 2–4 weeks. For documented chronic bacterial prostatitis, a 4- to 6-week course of antibiotics is often necessary.

Answer 283

Xanthogranulomatous pyelonephritis is treated with nephrectomy. .

Answer 284

Percutaneous drainage can be used as the initial therapy in emphysematous pyelonephritis and can be followed by elective nephrectomy as needed.

Answer 285

Continuous prophylaxis and postcoital prophylaxis usually entail low doses of TMP-SMX or nitrofurantoin. These regimens are all highly effective during the period of active

Answer 286

neutropenic patients and renal transplant recipients.

Answer 287

schistosome egg

Answer 288

Symmers clay pipestem fibrosis

Answer 289

Antigen excess from eggs results in the formation of soluble immune complexes, which may be deposited in several tissues and initiate a serum sickness–like illness. . The onset occurs between 2 weeks and 3 months after exposure to the parasite

Answer 290

dying cercariae that trigger innate immune responses A particularly severe form of cercarial dermatitis is commonly seen after exposure to cercariae from avian schistosomes. These cercariae cannot complete their development in humans and die in the skin, causing an inflammatory allergic reaction. This form of cercarial dermatitis can occur in people who have been in contact with water from lakes (e.g., in Europe or the United States) where various species of water birds, such as ducks, geese, and swans, are found

Answer 291

mesenteric veins

Answer 292

A characteristic sign in the active stage is painless, terminal hematuria. Dysuria and suprapubic discomfort or pain are associated with active urogenital schistosomiasis and may persist throughout the course of active infection. Eggs deposited in the bladder mucosa may give rise to an intense inflammatory response of the bladder wall, which may cause ureteric obstruction and lead to hydroureter and hydronephrosis. These early inflammatory lesions, including obstructive uropathy, can be visualized by ultrasonography

Answer 293

As the infection progresses, the inflammatory component decreases and fibrosis becomes more prominent. The symptoms at this stage are nocturia, urine retention, dribbling, and incontinence. Cystoscopy reveals “sandy patches” composed of large numbers of calcified eggs surrounded by fibrous tissue and an atrophic mucosal surface. The ureters are less commonly involved, but ureteral fibrosis can cause irreversible obstructive uropathy that can progress to uremia

Answer 294

squamous cell carcinoma of the urinary bladder

Answer 295

stool, rectal biopsy, pap smear (S. mansoni and S. hematobium) and semen samples (S. hematobium) Schistosoma DNA can be detected in cerebrospinal fluid samples for diagnosis of neuroschistosomiasis

Answer 296

O VibriOOOO

Answer 297

C. 5-7 weeks

Answer 298

B. Elderly

Answer 299

asymptomatic carriage

Answer 300

fever Fever of unknown origin may be the only manifestation of liver abscess, especially in the elderly

Answer 301

The incubation period for measles is ~10 days to fever onset and 14 days to rash onset

Answer 302

2 The characteristic rash of measles begins 2 weeks after infection, when the clinical manifestations are most severe, and signal the host’s immune response to the replicating virus. Headache, abdominal pain, vomiting, diarrhea, and myalgia may be present

Answer 303

third or fourth

Answer 304

(1) a generalized maculopapular rash of at least 3 days’ duration (2) fever of at least 38.3°C (101°F); and (3) cough, coryza, or conjunctivitis.

Answer 305

subacute sclerosing panencephalitis (SSPE)

Answer 306

12–15 1–3

Answer 307

A person is most infectious from 2 days before until 5 days after onset of parotitis or other salivary gland swelling. However, mumps virus has been detected in saliva as early as 7 days before onset and as late as 9 days after onset of these manifestations. Mumps virus has been isolated from urine and seminal fluid up to 14 days after onset of parotitis, although no studies have assessed transmissibility of the virus through these fluids

Answer 308

5 (range, 3–7 days) 10 Parotitis is generally bilateral and may not occur synchronously on both sides

Answer 309

The most frequent complications of mumps include orchitis, oophoritis, mastitis, pancreatitis, hearing loss, meningitis, and encephalitis Orchitis -most common; 30% of unvaccinated and 6% of vaccinated

Answer 310

True although an increase in parotitis cases may also result from increased influenza activity— specifically, infection with influenza A virus subtype H3N2.

Answer 311

Mumps virus and viral RNA can be detected in blood, saliva, urine, and CSF. Buccal or oral swabs provide the best specimens for virus detection As maximal viral shedding occurs within 5 days after symptom onset, specimens for mumps virologic testing ideally should be collected as close to parotitis onset as possible. The diagnostic yield of urine specimens increases over time up to 10 days after parotitis onset, but buccal specimens are more likely than urine specimens to result in virus detection at any time point.

Answer 312

25 There is no known immune correlate of protection for mumps; a positive IgG titer indicates only that a person has been exposed to mumps virus through either vaccination or natural infection and does not predict protection against infection.

Answer 313

Innate immunity is the most important defense mechanism against hematogenously disseminated candidiasis, and the neutrophil is the most potent component of this defense

Answer 314

The brain, chorioretina, heart, and kidneys are most commonly infected and the liver and spleen are less commonly affected in nonneutropenic hosts (but most often involved in neutropenic patients)

Answer 315

Echinocandin

Answer 316

Isolates of C. glabrata and C. krusei are less sensitive to fluconazole and more sensitive to polyenes and echinocandins C. parapsilosis is less sensitive to echinocandins in vitro; however, this lesser sensitivity is considered clinically insignificant.

Answer 317

True Similarly, Candida in the urine of a patient with an indwelling bladder catheter may represent colonization only, rather than bladder or kidney infection. However, the threshold for systemic treatment is lower in general in severely ill patients in this category since it is impossible to distinguish colonization from lower or upper urinary tract infection.

Answer 318

Hematogenous Candida endophthalmitis is a special problem requiring ophthalmologic consultation. When lesions are expanding or are threatening the macula, an IV polyene combined with flucytosine (25 mg/kg four times daily) has been the regimen of choice, although comparative studies with other regimens have not yet been reported.

Answer 319

True All patients with candidemia should undergo ophthalmologic examination because of the relatively high frequency of this ocular complication Hematogenous Candida endophthalmitis(up to 15–20% in some case series)

Answer 320

hematogenous

Answer 321

Among young adults and adolescents, N. gonorrhoeae is the most commonly implicated organism. S. aureus accounts for most nongonococcal isolates in adults of all ages Infections after surgical procedures or penetrating injuries are due most often to S. aureus and occasionally to other gram-positive bacteria or gram-negative bacilli

Answer 322

Patients with rheumatoid arthritis have the highest incidence of infective arthritis (most often secondary to S. aureus) because of chronically inflamed joints; glucocorticoid therapy; and frequent breakdown of rheumatoid nodules, vasculitic ulcers, and skin overlying deformed joints Polyarticular infection is most common among patients with rheumatoid arthritis and may resemble a flare of the underlying disease

Answer 323

S. aureus Cultures of synovial fluid are positive in >90% of cases of infectious arthritis

Answer 324

e. If there are gram-positive cocci on the smear, IV vancomycin (15−20 mg/kg/dose) every 8–12 h should be started empirically. If methicillin-resistant S. aureus is an unlikely pathogen (e.g., when it is not widespread in the community), cefazolin (2 g every 8 h), oxacillin (2 g every 4 h), or nafcillin (2 g every 4 h) should be given.

Answer 325

If initial Gram’s stain shows gram-negative bacilli, an IV thirdgeneration cephalosporin such as cefotaxime (1 g every 8 h) or ceftriaxone (1–2 g every 24 h) provides adequate empirical coverage for most community-acquired infections. In addition, cefepime (2 g every 8−12 h) or ceftazidime (2 g every 8 h) should be given to IV drug users and to other patients in whom P. aeruginosa may be the responsible agent. Double coverage of Pseudomonas with cephalosporin and ciprofloxacin or aminoglycoside can be considered in severely ill patients

Answer 326

Staphylococcal-4 weeks Pneumococcal and Strep and Hib- 2 weeks G- bacilli - 3 to4 weeks

Answer 327

Septic arthritis of the hip is best managed with arthrotomy, particularly in young children, in whom infection threatens the viability of the femoral head. Septic joints do not require immobilization except for pain control before symptoms are alleviated by treatment. Weight bearing should be avoided until signs of inflammation have subsided, but frequent passive motion of the joint is indicated to maintain full mobility

Answer 328

True and blood cultures are positive in <45% of patients A single joint such as the hip, knee, ankle, or wrist is usually involved. Synovial fluid, which contains >50,000 leukocytes/μL, can be obtained with ease

Answer 329

Initial treatment consists of ceftriaxone (1 g IV or IM every 24 h) to cover possible penicillin-resistant organisms. Once local and systemic signs are clearly resolving, a 7-day course of antibiotics may be completed with daily IM ceftriaxone given at 250 mg daily. An oral fluoroquinolone such as ciprofloxacin (500 mg twice daily) may be used if the organism is known to be susceptible. If penicillinsusceptible organisms are isolated, amoxicillin (500 mg three times daily) may be used

Answer 330

The most common presentation is chronic granulomatous monoarthritis

Answer 331

Poncet’s disease

Answer 332

Treatment includes surgery and high doses of parenteral antibiotics, which are given for 4–6 weeks because bone is usually involved In most cases, the prosthesis must be removed and replaced to cure the infection

Answer 333

1. Fever ≥38.3°C (≥101°F) on at least two occasions 2. Illness duration of ≥3 weeks 3. No known immunocompromised state 4. Diagnosis that remains uncertain after a thorough history-taking, physical examination, and the following obligatory investigations: determination of erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) level; platelet count; leukocyte count and differential; measurement of levels of hemoglobin, electrolytes, creatinine, total protein, alkaline phosphatase, alanine aminotransferase, aspartate aminotransferase, lactate dehydrogenase, creatine kinase, ferritin, antinuclear antibodies, and rheumatoid factor; protein electrophoresis; urinalysis; blood cultures (n = 3); urine culture; chest x-ray; abdominal ultrasonography; and tuberculin skin test (TST) or interferon γ release assay (IGRA).

Answer 334

Up to half of all infections in patients with FUO outside Western nations are caused by Mycobacterium tuberculosis, which is a less common cause in Western Europe and probably also in the United States

Answer 335

systemic lupus erythematosus and antiphospholipid syndrome

Answer 336

Although most tumors can present with fever, malignant lymphoma is by far the most common diagnosis of FUO among the neoplasms. Sometimes the fever even precedes lymphadenopathy detectable by physical examination.

Answer 337

More common causes of drug-induced fever are allopurinol, carbamazepine, lamotrigine, phenytoin, sulfasalazine, furosemide, antimicrobial drugs (especially sulfonamides, minocycline, vancomycin, β-lactam antibiotics, and isoniazid), some cardiovascular drugs (e.g., quinidine), and some antiretroviral drugs (e.g., nevirapine)

Answer 338

Factitious fever (fever artificially induced by the patient—for example, by IV injection of contaminated water) should be considered in all patients but is more common among young women in health-care professions.

Answer 339

In fraudulent fever, the patient is normothermic but manipulates the thermometer. Simultaneous measurements at different body sites (rectum, ear, mouth) should rapidly identify this diagnosis. Another clue to fraudulent fever is dissociation between pulse rate and temperature

Answer 340

False Abdominal ultrasound is preferred to abdominal CT as an obligatory test because of relatively low cost, lack of radiation burden, and absence of side effects.

Answer 341

Blood culture --> 3 Urine CS --> 1 Performing more than three blood cultures or more than one urine culture is useless in patients with FUO in the absence of PDCs (e.g., a high level of clinical suspicion of endocarditis) Repeat cultures useful only when previously cultured samples were collected during abx tx or within 1 week after its discontinuation f

Answer 342

Cryoglobulin, fundoscopy (r/o retinal vasculitis)

Answer 343

Ff up new PDCs Consider NSAID

Answer 344

Further dx test Do therapeutic trial Empirical therapeutic trials with antibiotics, glucocorticoids, or antituberculous agents should be avoided in FUO except when a patient’s condition is rapidly deteriorating after the aforementioned diagnostic tests have failed to provide a definite diagnosis

Answer 345

All medications, including nonprescription drugs and nutritional supplements, should be discontinued early in the evaluation to exclude drug fever. If fever persists beyond 72 h after discontinuation of the suspected drug, it is unlikely that this drug is the cause

Answer 346

Pathologic FDG uptake is quickly eradicated by treatment with glucocorticoids in many diseases, including vasculitis and lymphoma; therefore, glucocorticoid use should be stopped or postponed until after FDGPET/CT is performed

Answer 347

Liver biopsy is an invasive procedure that carries the possibility of complications and even death. Therefore, it should not be used for screening purposes in patients with FUO except in those with PDCs for liver disease or miliary tuberculosis

Answer 348

Familial Mediterranean Fever --> colchicine Still's dse --> NSAIDs Giant cell arteritis --> glucocorticoids Polymyalgia rheumatica --> glucocorticoids

Answer 349

Commonly used antibiotic regimens for the treatment of febrile patients in whom prolonged neutropenia (>7 days) is anticipated include (1) ceftazidime or cefepime, (2) piperacillin/tazobactam, or (3) imipenem/cilastatin or meropenem. All three regimens have shown equal efficacy in large trials. All three are active against P. aeruginosa and a broad spectrum of aerobic gram-positive and gram-negative organisms. Despite the frequent involvement of coagulase-negative staphylococci, the initial use of vancomycin or its automatic addition to the initial regimen has not resulted in improved outcomes, and the antibiotic does exert toxic effects. For these reasons, only judicious use of vancomycin is recommended

Answer 350

neutropenic patient remains febrile despite 4–7 days of treatment with antibacterial agents Before the introduction of newer azoles into clinical practice, amphotericin B was the mainstay of antifungal therapy. Echinocandins (e.g., caspofungin) are useful in the treatment of infections caused by azole-resistant Candida strains as well as in therapy for aspergillosis and have been shown to be equivalent to liposomal amphotericin B for the empirical treatment of patients with prolonged fever and neutropenia

Answer 351

Any patient receiving more than a maintenance dose of glucocorticoids (e.g., in many treatment regimens for diffuse lymphoma) should also receive prophylactic TMPSMX because of the risk of Pneumocystis infection; those with ALL should receive such prophylaxis for the duration of chemotherapy

Answer 352

In adults, primary bacterial peritonitis (PBP) occurs most commonly in conjunction with cirrhosis of the liver (frequently the result of alcoholism).

Answer 353

The presentation of PBP differs from that of secondary peritonitis. The most common manifestation is fever, which is reported in up to 80% of patients. Ascites is found but virtually always predates infection.

Answer 354

False For primary/spontaenous only The finding of >250 PMNs/μL is diagnostic for PBP, according to Conn. This criterion does not apply to secondary peritonitis

Answer 355

A mortality benefit from albumin (1.5 g/kg of body weight within 6 h of detection and 1.0 g/kg on day 3) has been demonstrated for patients who present with serum creatinine levels ≥1 mg/dL, blood urea nitrogen levels ≥30 mg/dL, or total bilirubin levels ≥4 mg/dL but not for patients who do not meet these criteria

Answer 356

Third-generation cephalosporins such as cefotaxime (2 g q8h, administered IV) provide reasonable initial coverage in moderately ill patients. Broad-spectrum antibiotics, such as β-lactam/βlactamase inhibitor combinations (e.g., piperacillin/tazobactam, 3.375 g q6h IV for adults with normal renal function) or ceftriaxone (2 g q24h IV), also are options. Broader empirical coverage aimed at resistant hospital-acquired gram-negative bacteria (e.g., treatment with a carbapenem or newer agents, such as ceftolozanetazobactam or ceftazidime-avibactam) may be appropriate for nosocomially acquired PBP until culture results become available. Empirical coverage for anaerobes is NOT necessary.

Answer 357

Patients with PBP usually respond within 72 h to appropriate antibiotic therapy. Antimicrobial treatment can be administered for as little as 5 days if rapid improvement occurs and blood cultures are negative, but a course of up to 2 weeks may be required for patients with bacteremia and for those whose improvement is slow

Answer 358

Prophylactic regimens for adults with normal renal function include fluoroquinolones (ciprofloxacin, 500 mg weekly; or norfloxacin, 400 mg/d) or trimethoprim-sulfamethoxazole (one double-strength tablet daily). However, long-term administration of broad-spectrum antibiotics in this setting has been shown to increase the risk of severe staphylococcal infections. There is increased interest in using rifaximin, a broad-spectrum antibiotic that is used already for hepatic encephalopathy and is not absorbed, for PBP prophylaxis (1200 mg daily).

Answer 359

The organisms found almost always constitute a mixed flora in which facultative gram-negative bacilli and anaerobes predominate, especially when the contaminating source is colonic.

Answer 360

trauma, where the possibility of a hemoperitoneum may need to be excluded early

Answer 361

Community acquired infections associated with mild to moderate disease can be treated with β-lactam/β-lactamase inhibitor combinations (e.g., ticarcillin/clavulanate, 3.1 g q4–6h IV; or piperacillin/tazobactam, 3.375 g q6h IV) or a combination of either a fluoroquinolone (e.g., levofloxacin, 750 mg q24h IV) or a third-generation cephalosporin (e.g., ceftriaxone, 2 g q24h IV) plus metronidazole (500 mg q8h IV). Eravacycline is a newer antibiotic in the tetracycline class that has been approved by the U.S. FDA for treatment of complicated intraabdominal infections (1 mg/kg q12h IV). Patients in ICU and/or those with health care–associated infections should receive antibiotics targeting more resistant gram-negative organisms such as Pseudomonas aeruginosa—e.g., imipenem (500 mg q6h IV), meropenem (1 g q8h IV), higher-dose piperacillin/tazobactam (4.5 g IV q6h), or drug combinations such as cefepime (2 g IV q8h) or ceftazidime (2 g IV q8h) plus metronidazole For patients known to be colonized with (VRE), linezolid or daptomycin, should be included. Antifungal coverage is warranted if there is growth of Candida species from a sterile site. Patients who are known to be colonized with highly resistant gram-negative organisms may require treatment with a newer agent such as ceftazidime/ avibactam or ceftolozane/tazobactam.

Answer 362

Unlike PBP and secondary peritonitis, which are caused by endogenous bacteria, CAPDassociated peritonitis usually involves skin organisms. The most common organisms are Staphylococcus species, which accounted for ~45% of cases in one series. Like PBP, CAPD-associated peritonitis is usually caused by a single organism. Peritonitis is, in fact, the most common reason for discontinuation of CAPD.

Answer 363

the clinician should use the percentage of PMNs rather than the absolute number of WBCs to diagnose peritonitis. As the normal peritoneum has very few PMNs, a proportion above 50% is strong evidence of peritonitis even if the absolute WBC count does not reach 100/μL.

Answer 364

first-generation cephalosporin such as cefazolin and a fluoroquinolone or a third-generation cephalosporin such as ceftazidime may be reasonable; in areas with high rates of MRSA, vancomycin should be used and gram-negative coverage may need to be broadened—e.g., with an aminoglycoside, ceftazidime, cefepime, or a carbapenem. Broad coverage including vancomycin should be particularly considered for patients with septic physiology or exit-site infections.

Answer 365

The clinical response to an empirical treatment regimen should be rapid; if the patient has not responded after 48–96 h of treatment, new samples should be collected for cell counts and cultures, and catheter removal should be considered. For patients who lack exit-site or tunnel infection, the typical duration of antibiotic treatment is 14 days

Answer 366

Treatment of intraabdominal infections involves determination of the initial focus of infection, administration of broad-spectrum antibiotics targeting the organisms involved, and performance of a drainage procedure if one or more definitive abscesses have formed.

Answer 367

The appropriate duration of antibiotic treatment for abdominal abscesses depends on whether the presumptive source of the intraabdominal infection has been controlled. With adequate source control, antibiotic treatment may be limited to 4 or 5 days

Answer 368

The liver is the organ most subject to the development of abscesses

Answer 369

. The single most reliable laboratory finding is an elevated serum concentration of alkaline phosphatase, which is documented in 70% of patients with liver abscesses. Other tests of liver function may yield normal results, but 50% of patients have elevated serum levels of bilirubin, and 48% have elevated concentrations of aspartate aminotransferase.

Answer 370

With hematogenous spread of infection, usually only a single organism is encountered; this species may be S. aureus or a streptococcal species such as one in the Streptococcus milleri group

Answer 371

Drainage is the mainstay of therapy for intraabdominal abscesses, including liver abscesses; the approach can be either percutaneous (with a pigtail catheter kept in place or possibly with a device that can perform pulse lavage to fragment and evacuate the semisolid contents of a liver abscess), transluminal (with endoscopic ultrasound guidance), or surgical.

Answer 372

Treatment of candidal liver abscesses often entails initial administration of liposomal amphotericin B (3–5 mg/kg IV daily) or an echinocandin, with subsequent fluconazole therapy. In some cases, therapy with fluconazole alone (6 mg/kg daily) may be used—e.g., in clinically stable patients whose infecting isolate is susceptible to this drug.

Answer 373

Although splenic abscesses may arise occasionally from contiguous spread of infection or from direct trauma to the spleen, hematogenous spread of infection is more common. Bacterial endocarditis is the most common associated infection

Answer 374

Streptococcal species are the most common bacterial isolates from splenic abscesses, followed by S. aureus—presumably reflecting the associated endocarditis Salmonella species are seen fairly commonly, especially in patients with sickle cell hemoglobinopathy

Answer 375

Because of the high mortality figures reported for splenic abscesses, splenectomy with adjunctive antibiotics has traditionally been considered standard treatment and remains the best approach for complex, multilocular abscesses or multiple abscesses. However, percutaneous drainage has worked well for single, small (<3-cm) abscesses in some studies and may also be useful for patients with high surgical risk. Patients undergoing splenectomy should be vaccinated against encapsulated organisms (Streptococcus pneumoniae, Haemophilus influenzae, Neisseria meningitidis). The most important factor in successful treatment of splenic abscesses is early diagnosis.

Answer 376

Now, in contrast, >75% of perinephric and renal abscesses arise from a urinary tract infection. Infection ascends from the bladder to the kidney, with pyelonephritis preceding abscess development

Answer 377

The organisms most frequently encountered in perinephric and renal abscesses are E. coli, Proteus species, and Klebsiella species. E. coli, the aerobic species most commonly found in the colonic flora, seems to have unique virulence properties in the urinary tract, including factors promoting adherence to uroepithelial cells

Answer 378

Perinephric or renal abscess should be most seriously considered when a patient presents with symptoms and signs of pyelonephritis and remains febrile after 4 or 5 days of treatment. Moreover, when a urine culture yields a polymicrobial flora, when a patient is known to have renal stones, or when fever and pyuria coexist with a sterile urine culture, these diagnoses should be entertained. If a renal or perinephric abscess is diagnosed, nephrolithiasis should be excluded, especially when a high urinary pH suggests the presence of a urea-splitting organism

Answer 379

S. aureus is most likely to be isolated when a psoas abscess arises from hematogenous spread or a contiguous focus of osteomyelitis; a mixed enteric flora is the most likely etiology when the abscess has an intraabdominal or pelvic source.

Answer 380

The incubation period of chickenpox ranges from 10 to 21 days but is usually 14–17 days

Answer 381

secondary bacterial superinfection of the skin, which is usually caused by Streptococcus pyogenes or Staphylococcus aureus, including strains that are methicillin-resistant

Answer 382

Varicella pneumonia develops more often in adults (up to 20% of cases) than in children and is particularly severe in pregnant women.

Answer 383

The dermatomes from T3 to L3 are most frequently involved

Answer 384

The onset of disease is heralded by pain within the dermatome, which may precede lesions by 48–72 h; an erythematous maculopapular rash evolves rapidly into vesicular lesions may remain few in number and continue to form for only 3–5 days. The total duration of disease is generally 7–10 days; however, it may take as long as 2–4 weeks for the skin to return to normal

Answer 385

In Ramsay Hunt syndrome, pain and vesicles appear in the external auditory canal, and patients lose their sense of taste in the anterior two-thirds of the tongue while developing ipsilateral facial palsy. The geniculate ganglion of the sensory branch of the facial nerve is involved

Answer 386

Specimens for detection of VZV DNA by PCR include lesions, blood, and saliva

Answer 387

Acyclovir (800 mg by mouth five times daily), valacyclovir (1 g three times daily), or famciclovir (250 mg three times daily) for 5–7 days is recommended for adolescents and adults with chickenpox of ≤24 h duration In severely immunocompromised hosts (e.g., transplant recipients, patients with lymphoproliferative malignancies), both chickenpox and herpes zoster (including disseminated disease) should be treated, at least at the outset, with IV acyclovir, which reduces the occurrence of visceral complications but has no effect on healing of skin lesions or pain. The dose is 10 mg/kg every 8 h for 7 days. For low-risk immunocompromised hosts, oral therapy with valacyclovir or famciclovir appears beneficial

Answer 388

This product should be given within 96 h (preferably within 72 h) of the exposure but may be administered up to 10 days with similar efficacy

Answer 389

E. histolytica

Answer 390

Metronidazole

Answer 391

The earliest intestinal lesions are micro-ulcerations of the mucosa of the cecum, sigmoid colon, or rectum that release erythrocytes, inflammatory cells, and epithelial cells

Answer 392

liver Most patients are febrile and have right-upper quadrant pain, which may be dull or pleuritic in nature and may radiate to the shoulder. Point tenderness over the liver and right-sided pleural effusion are common

Answer 393

A hepatobronchial fistula may cause cough productive of large amounts of necrotic material that may contain amebae. This dramatic complication carries a good prognosis. Abscesses that rupture into the peritoneum may present as an indolent leak or an acute abdomen and require both percutaneous catheter drainage and medical therapy. Rupture into the pericardium, usually from abscesses of the left lobe of the liver, carries the gravest prognosis; it can occur during medical therapy and requires surgical drainage.

Answer 394

Fecal findings suggestive of amebic colitis include a positive test for heme, a paucity of neutrophils, and amebic cysts or trophozoites. The definitive diagnosis of amebic colitis is made by the demonstration of hematophagous trophozoites of E. histolytica. Because trophozoites are killed rapidly by water, drying, or barium, it is important to examine at least three fresh stool specimens

Answer 395

More than 90% of patients respond dramatically to metronidazole therapy with decreases in both pain and fever within 72 h.

Answer 396

Indications for aspiration of liver abscesses are (1) the need to rule out a pyogenic abscess, particularly in patients with multiple lesions; (2) the lack of a clinical response in 3–5 days (3) the threat of imminent rupture; and (4) the need to prevent rupture of left-lobe abscesses into the pericardium. There is no evidence that aspiration, even of large abscesses (up to 10 cm), accelerates healing. Percutaneous drainage may be successful even if the liver abscess has already ruptured. Surgery should be reserved for instances of bowel perforation and rupture into the pericardium

Answer 397

M Reported infections with group N and group P viruses are rare and confined almost entirely to residents of Cameroon or travelers from Cameroon

Answer 398

C In sub-Saharan Africa, home to approximately two-thirds of all individuals living with HIV/AIDS, most infections are caused by subtype C

Answer 399

Blood transfusion The quantity of HIV-1 in plasma (viral load) is a primary determinant of the risk of HIV-1 transmission

Answer 400

The following fluids also are considered potentially infectious: cerebrospinal fluid, synovial fluid, pleural fluid, peritoneal fluid, pericardial fluid, and amniotic fluid

Answer 401

It is this establishment of a chronic, persistent infection that is the hallmark of HIV disease.

Answer 402

The principal targets of neutralizing antibodies against HIV are the envelope proteins gp120 and gp41. HIV employs at least three mechanisms to evade neutralizing antibody responses: hypervariability in the primary sequence of the envelope, extensive glycosylation of the envelope, and conformational masking of neutralizing epitopes

Answer 403

Most patients are relatively asymptomatic while this progressive decline is taking place and are often described as being in a state of clinical latency

Answer 404

the CDC case definition of stage 3 (AIDS) includes all HIV-infected individuals >5 years of age with CD4+ T-cell counts below this level

Answer 405

Regardless of the portal of entry of HIV, lymphoid tissues are the major anatomic sites for the establishment and propagation of HIV infection

Answer 406

Mycobacterium tuberculosis is the most common opportunistic infection in HIV-infected individuals

Answer 407

immune reconstitution inflammatory syndrome (IRIS) The immunopathogenesis of this syndrome is felt to be related to an increase in immune response against the presence of residual antigens that are usually microbial and is most commonly seen with underlying mycobacterial (Mycobacterium tuberculosis [TB] or avium complex [MAC]), fungal (cryptococcal) and viral (CMV, HHV) infections.

Answer 408

True A relative CD8+ T lymphocytosis is generally associated with high levels of HIV plasma viremia and likely reflects an immune response to the virus as well as dysregulated homeostasis associated with generalized immune activation

Answer 409

True Circulating monocytes are generally normal in number in HIV-infected individuals; however, there is evidence of increased activation within this lineage Tissue macrophages are an important source of HIV during the inflammatory response associated with opportunistic infections and can serve as persistent reservoirs of HIV infection, thus representing an obstacle to the eradication of HIV by antiretroviral drugs T cells and B cells --> decreased

Answer 410

HIV-1–associated nephropathy (HIVAN) is a form of focal sclerosing glomerulonephritis caused by direct infection of kidney epithelial cells with HIV. HIVAN is more common in persons of African descent

Answer 411

3–6 12 Detection of these antibodies forms the basis of many diagnostic screening tests for HIV infection

Answer 412

The first antibodies detected are those directed against the immunodominant region of the envelope gp41, followed by the appearance of antibodies to the structural or gag protein p24 and the gag precursor p55. Antibodies to p24 gag are followed by the appearance of antibodies to the outer envelope glycoprotein (gp120), the gag protein p17, and the products of the pol gene (p31 and p66) gp 41 --> 24 --> 55 --> 120 --> 17 --> 31 and 66

Answer 413

Fourth-generation HIV-1/2 antigen antibody immunoassay If the result is negative, unless there is strong reason to suspect early HIV infection (as in a patient exposed within the previous 3 months), the diagnosis is ruled out and retesting should be performed only as clinically indicated. If the repeat is negative on two occasions, one can assume that the initial positive reading was due to a technical error in the performance of the assay and that the patient is negative

Answer 414

The CD4+ T-cell count is the laboratory test generally accepted as the best indicator of the immediate state of immunologic competence of the patient with HIV infection.

Answer 415

CMV, mycobacteria of the M. avium complex (MAC), and/or T. gondi

Answer 416

profound neutropenia, glucocorticoid use, and underlying respiratory disease

Answer 417

1-3months 80% involve the lungs and are community acquired

Answer 418

brain but also to the skin, thyroid, bone, kidney, liver, gastrointestinal tract, eye endophthalmitis), and heart valve. In acute disease, hemorrhagic infarction is most typical, and cerebral abscess is common

Answer 419

Most cases of Aspergillus endocarditis are prostheticvalve infections resulting from contamination during surgery.

Answer 420

one or more pulmonary cavities expanding over a period of months or years in association with pulmonary symptoms and systemic manifestations such as fatigue and weight loss. An irregular internal cavity surface and thickened cavity walls are typical and indicative of disease activity. Pleural thickening and pericavitary infiltrates are typical and most obvious if a positron emission tomography scan has been done as part of the workup.

Answer 421

The cardinal diagnostic test is detection of Aspergillus-specific IgE (or a positive skin-prick test in response to A. fumigatus extract) together with an elevated serum level of total IgE (usually >1000 IU/mL).

Answer 422

The histologic hallmarks of allergic fungal sinusitis are local eosinophilia and Charcot-Leyden crystals.

Answer 423

(1) a positive culture of a sample taken directly from an ordinarily sterile site (e.g., a brain abscess) or (2) positive results of both histologic testing and culture (or molecular confirmation of Aspergillus spp.) of a sample taken from an affected organ (e.g., sinuses or skin).

Answer 424

Voriconazole, isavuconazole and posaconazole are the preferred agents for invasive aspergillosis; caspofungin, micafungin, and lipidassociated AmB are second-line agents. AmB is not active against A. terreus or A. nidulans;

Answer 425

Voriconazole is currently the preferred oral agent for chronic aspergillosis with itraconazole or posaconazole as substitutes when failure, emergence of resistance, or adverse events occur.

Answer 426

P-osaconazole P-rophylaxis

Answer 427

Surgical treatment is important in several forms of aspergillosis, including fungal ball of the sinus and single aspergillomas, in which surgery is curative; invasive aspergillosis involving bone, heart valve, sinuses, and proximal areas of the lung (to avoid catastrophic hemoptysis); brain abscess; keratitis; and endophthalmitis. In allergic fungal sinusitis, removal of abnormal mucus and polyps, with local and occasionally systemic glucocorticoid treatment, usually leads to resolution. Persistent or recurrent signs and symptoms may require more extensive surgery (ethmoidectomy) and possibly antifungal therapy. Surgery is problematic in chronic cavitary pulmonary aspergillosis, usually resulting in serious complications. Bronchial artery embolization is preferred for problematic hemoptysis.

Answer 428

Clinicians must recognize that PCP can occur at CD4+ T-cell counts >200/μL in any immunosuppressed population including persons with HIV infection. Such occurrences are especially common in patients who are immunosuppressed due to causes other than HIV infection, especially among patients who have undergone solid-organ transplantation, since CD4+ T-cell counts are not as sensitive and specific indicators of PCP as they are in PLWH.

Answer 429

True High-resolution chest CT shows diffuse ground-glass opacities in virtually all patients with PCP, often before a routine chest radiograph becomes abnormal.A normal chest CT essentially rules out the diagnosis of PCP

Answer 430

The treatment of choice for PCP is trimethoprim-sulfamethoxazole (TMP-SMX), given either IV or PO for 14 days to non-HIVinfected patients with mild disease and for 21 days to all other patients Intravenous pentamidine or the combination of clindamycin plus primaquine is an option for patients who cannot tolerate TMP-SMX and for patients in whose treatment TMP-SMX appears to be failing

Answer 431

A major advance in therapy for PCP was the recognition that glucocorticoids could improve survival rates among PLWH with moderate to severe disease (room air PO2 <70 mmHg or alveolar–arterial oxygen gradient ≥35 mmHg).

Answer 432

the first 2 weeks of therapy for PCP in most situations.

Answer 433

B A and C affects multiple species

Answer 434

There is only one serotype of RSV, but antigenic variability does occur in circulating field strains.

Answer 435

Rhinovirus

Answer 436

MERS-CoV is a zoonotic virus (transmitted between animals and people). The virus likely emerged from bats in the Middle East, although studies have shown that humans are infected through direct or indirect contact with an intermediate host—infected dromedary camels.

Answer 437

Advanced age is the principal risk factor for severe illness from COVID-19 (marked by need for hospitalization, intensive care, and mechanical ventilation). Over 95% of COVID-19 deaths occur in people over age 45, and >80% of deaths occur in people over age 65. Male sex is associated with higher risk of severe disease (odds ratio, ~1.8). Most individuals who die have preexisting comorbidities. The risk of severe COVID-19 illness increases markedly with elevated body mass index (BMI).

Answer 438

Nonsteroidal anti-inflammatory drugs (NSAIDs) are often used as antipyretic agents, but questions have been raised about a possible association between NSAID use and worse outcomes with COVID-19; when possible, the preferred antipyretic agent is acetaminophen.

Answer 439

3–6 Following the initiation of therapy or any change in therapy, plasma HIV RNA levels should be monitored approximately every 4 weeks until the effectiveness of the therapeutic regimen is determined by the development of a new steady-state level of HIV RNA.

Answer 440

May stop prophylaxis if CD4+ T-cell count >200/μL for ≥3 months Same with T. Gondii

Answer 441

May stop prophylaxis once ART initiated

Answer 442

The most common finding on chest x-ray is either a normal film, if the disease is suspected early, or a faint bilateral interstitial infiltrate.

Answer 443

it is recommended that initiation of ART be delayed in antiretroviral-naïve patients with CD4 counts >50 cells/μL until 2–4 weeks following the initiation of treatment for TB.

Answer 444

The finding of two consecutive sputum samples positive for MAC is highly suggestive of pulmonary infection. Cultures may take 2 weeks to turn positive.

Answer 445

The most common form of heart disease is coronary heart disease.

Answer 446

Oral hairy leukoplakia presents as white, frondlike lesions, generally along the lateral borders of the tongue and sometimes on the adjacent buccal mucosa

Answer 447

Note 3 samples for stool ova and parasites

Answer 448

Nevirapine has been associated with at times fatal fulminant and cholestatic hepatitis, hepatic necrosis, and hepatic failure

Answer 449

Proteinuria is the hallmark of this disorder A definitive diagnosis is obtained through renal biopsy

Answer 450

The most common presentation of syphilis in the HIV-infected patient is that of condylomata lata, a form of secondary syphilis

Answer 451

Anemia is the most common hematologic abnormality in HIV-infected patients and, in the absence of a specific treatable cause, is independently associated with a poor prognosis

Answer 452

. A characteristic feature of zidovudine therapy is an elevated mean corpuscular volume (MCV) Also associated with lengthening of eyelashes

Answer 453

Fungal meningitis is the leading infectious cause of meningitis in patients with AIDS . While the vast majority of these are due to C. neoformans, up to 12% may be due to C. gattii

Answer 454

Trigeminal although extension to the inferior and superior cervical ganglia also occurs. With genital infection, sacral nerve root ganglia (S2–S5) are most commonly affected. Autonomic ganglia, pelvic nerves, and vaginal nerve roots are commonly infected

Answer 455

recurrent herpes labialis

Answer 456

False Use of topical glucocorticoids may exacerbate symptoms and lead to involvement of deep structures of the eye

Answer 457

acute onset of fever and focal neurologic symptoms and signs, especially in the temporal lobe While brain biopsy has been the gold standard for defining HSV encephalitis, a highly sensitive and specific PCR for detection of HSV DNA in CSF has largely replaced biopsy for defining CNS infection

Answer 458

Most authorities recommend the administration of IV acyclovir to patients with presumed HSV encephalitis until the diagnosis is confirmed or an alternative diagnosis is made. All confirmed cases should be treated with IV acyclovir (30 mg/kg per day in three divided doses for 14–21 days).

Answer 459

Neurologic sequelae of HSV meningitis are rare. HSV is the most commonly identified cause of recurrent lymphocytic meningitis (Mollaret’s meningitis).

Answer 460

The predominant symptoms of HSV esophagitis are odynophagia, dysphagia, substernal pain, and weight loss. Multiple oval ulcerations appear on an erythematous base with or without a patchy white pseudomembrane. The distal esophagus is most commonly involved.

Answer 461

risk of mother-to-child transmission of HSV in the perinatal period is highest when the infection is acquired near the time of labor—that is, in previously HSV-seronegative women Isolation of HSV by cervicovaginal swab at the time of delivery is the greatest risk factor for intrapartum HSV transmission

Answer 462

For newly acquired genital HSV infection during pregnancy, most authorities recommend treatment with acyclovir (400 mg three times daily) or valacyclovir (500–1000 mg twice daily) for 7–10 days

Answer 463

HSV infection is best confirmed in the laboratory by detection of virus, viral antigen, or viral DNA in scrapings from lesions. HSV DNA detection by PCR is the most sensitive laboratory technique for detecting mucosal or visceral HSV infections and is the recommended test for laboratory confirmation of a diagnosis. Culture is indicated when antiviral sensitivity testing is required

Answer 464

Only valacyclovir has been subjected to clinical trials that demonstrated reduced transmission of HSV-2 infection between sexual partners Once-daily valacyclovir (500 mg)

Answer 465

The major side effect associated with IV acyclovir is transient renal insufficiency, usually due to crystallization of the compound in the renal parenchyma. This adverse reaction can be avoided if the medication is given slowly over 1 h and the patient is well hydrated.

Answer 466

Therapy with the antiviral drug foscarnet (40–80 mg/kg IV every 8 h until clinical resolution) is the only clinically demonstrated approach Because of its toxicity and cost, this drug is usually reserved for patients with extensive mucocutaneous infections

Answer 467

The diagnosis of cryptococcal meningitis is made by identification of organisms in spinal fluid with india ink examination or by the detection of cryptococcal antigen. Blood cultures for fungus are often positive. A biopsy may be needed to make a diagnosis of CNS cryptococcoma and to distinguish inadequately treated infection from immune reconstitution syndrome.

Answer 468

Initial treatment is with IV amphotericin B 0.7 mg/kg daily, or liposomal amphotericin 4–6 mg/kg daily, with flucytosine 25 mg/kg qid for at least 2 weeks if possible. Decreases in renal function in association with amphotericin can lead to increases in flucytosine levels and subsequent bone marrow suppression. Therapy continues with amphotericin alone until the CSF culture turns negative followed by fluconazole 400 mg/d PO for 8 weeks, and then fluconazole 200 mg/d until the CD4+ T-cell count has increased to >200 cells/μL for 6 months in response to ART

Answer 469

The most common causes are toxoplasmosis, progressive multifocal leukoencephalopathy, and CNS lymphoma

Answer 470

The most common clinical presentation of cerebral toxoplasmosis in patients with HIV infection is fever, headache, and focal neurologic deficits d by confusion, dementia, and lethargy, which can progress to coma. The diagnosis is usually suspected on the basis of MRI findings of multiple lesions in multiple locations, although in some cases only a single lesion is seen

Answer 471

The definitive diagnostic procedure is brain biopsy. However, given the morbidity rate that can accompany this procedure, it is usually reserved for the patient who has failed 2–4 weeks of empiric therapy for toxoplasmosis

Answer 472

Standard treatment is sulfadiazine and pyrimethamine with leucovorin as needed for a minimum of 4–6 weeks.

Answer 473

JC virus PML is the only known clinical manifestation of JC virus infection

Answer 474

Treatment consists of benzimidazole (2.5 mg/kg bid) or nifurtimox (2 mg/kg qid) for at least 60 days, followed by maintenance therapy for the duration of immunodeficiency with either drug at a dose of 5 mg/kg three times a week.

Answer 475

The most common peripheral neuropathy in patients with HIV infection is a distal sensory polyneuropathy (DSPN) also referred to as painful sensory neuropathy (HIV-SN),

Answer 476

The most common abnormal findings on funduscopic examination are cotton-wool spots. One of the most devastating consequences of HIV infection is CMV retinitis. Patients at high risk of CMV retinitis (CD4+ T-cell count <100/μL) should undergo an ophthalmologic examination every 3–6 months. The majority of cases of CMV retinitis occur in patients with a CD4+ T-cell count <50/μL.

Answer 477

CMV retinitis usually presents as a painless, progressive loss of vision. Patients may also complain of blurred vision, “floaters,” and scintillations. The disease is usually bilateral, although typically it affects one eye more than the other. The diagnosis is made on clinical grounds by an experienced ophthalmologist. The characteristic retinal appearance is that of perivascular hemorrhage and exudate.

Answer 478

Therapy for CMV retinitis consists of oral valganciclovir, IV ganciclovir, or IV foscarnet, with cidofovir as an alternative. Combination therapy with ganciclovir and foscarnet has been shown to be slightly more effective than either ganciclovir or foscarnet alone in the patient with relapsed CMV retinitis. A 3-week induction course is followed by maintenance therapy with oral valganciclovir. If CMV disease is limited to the eye, intravitreal injections of ganciclovir or foscarnet may be considered. Maintenance therapy is continued until the CD4+ T-cell count remains >100 μL for >6 months

Answer 479

True Generalized wasting is an AIDS-defining condition; it is defined as involuntary weight loss of >10% associated with intermittent or constant fever and chronic diarrhea or fatigue lasting >30 days in the absence of a defined cause other than HIV infection.

Answer 480

The initial lesion may be a small, raised, reddish-purple nodule on the skin a discoloration on the oral mucosa, or a swollen lymph node. Lesions often appear in sun-exposed areas, particularly the tip of the nose, and have a propensity to occur in areas of trauma (Koebner phenomenon)

Answer 481

Three main categories of lymphoma are seen in patients with HIV infection: grade III or IV immunoblastic lymphoma, Burkitt’s lymphoma, and primary CNS lymphoma. Immunoblastic lymphomas account for ~60% of the cases of lymphoma in patients with AIDS. The majority of these are diffuse large B-cell lymphomas (DLBCL). T

Answer 482

At least 80% of patients present with extranodal disease, and a similar percentage have B-type symptoms of fever, night sweats, and/ or weight loss. Virtually any site in the body may be involved. The most common extranodal site is the CNS, which is involved in approximately one-third of all patients with lymphoma.

Answer 483

A pregnancy test should be done in women in whom the drug efavirenz is being considered, and HLA-B5701 testing should be done in all patients in whom the drug abacavir is being considered. Hypersensitivity reaction In HLA-B5701+ individuals (can be fatal) in px taking Abacavir

Answer 484

initial regimen will include two nucleoside/nucleotide reverse transcriptase inhibitors (usually a tenofovir-based drug or abacavir + 3TC or FTC) plus a nonnucleoside reverse transcriptase inhibitor, an integrase inhibitor, or a protease inhibitor boosted with a pharmacokinetic enhancer (ritonavir or cobicistat).

Answer 485

TDF = greater than 70 TAF = greater than 30

Answer 486

Raltegravir

Answer 487

Atazanavir

Answer 488

cobicistat

Answer 489

50 During this same time there should be a rise in the CD4+ T-cell count of 100–150/cells μL that is also particularly brisk during the first month of therapy. Subsequently, one should anticipate a CD4+ T-cell count increase of 50–100 cells/year until numbers approach normal

Answer 490

Plasma HIV RNA levels should be monitored within 2–4 weeks after initiation of ART or following a change in regimen, every 4–8 weeks until HIV RNA levels are suppressed to <200 copies/mL, and then every 3–6 months during therapy.

Answer 491

Necrotizing fascitis Clostridial myonecrosis

Answer 492

HPV Recombinant Zoster

Answer 493

False Pregnancy only Most live vaccines are not secreted in the breast milk

Answer 494

Enterococci

Answer 495

Subacute IE + stable especially if with prior abx within precedig 2 weeks Rationale: delay allows obtaining blood for additional cultures unconfounded by empirical tx

Answer 496

Paravalvular abscess Extracardiac abscess Complications (embolic)

Answer 497

AV Dx test of choice: TEE Tx: Pacemaker

Answer 498

C. septicum --> anaerobe but o2 tolerant

Answer 499

Abdominal pain Most common: Streptococcus species Most common isolates reflect associated endocarditis If with sickle cell: Salmonella

Answer 500

A. PCV 13 should be given at least 8 weeks before PPSV 23 Giving PCV13 first allows for a strong immune response that enhances the efficacy of PPSV23 when administered later. PPSV23 should not be administered before PCV13 because it may blunt the immune response to PCV13 if given later

Answer 501

C. Azithromycin 500mg P.O. 1 hour before procedure

Answer 502

A. NSAID Withold abx and steroids if stable and no PDCs since may interfere with work ups

Answer 503

C. Dapsone 100mg/day + Clofazimine 50mg/day (unsupervised) and Rifampin 600mg/month + Clofazimine 300mg/month (supervised) x 1-2 years The clinical presentation of this patient, including multiple xanthoma-like nodules, leonine facies, clawing of fingers, and positive acid-fast bacilli (AFB) on skin biopsy, is consistent with multibacillary (MB) leprosy (lepromatous leprosy). The absence of lymphocytic infiltration and Langerhans giant cells with foamy macrophages on biopsy further supports the diagnosis.

Answer 504

C. Start doxycycline 100mg PO now then once daily until 4 weeks after leaving Palawan Doxy Dose: 100 mg orally once daily, starting 1–2 days before travel, continued during the stay, and for 4 weeks after leaving the malaria-endemic area Chloroquine and Mefloquine should be started 1-2 weeks before hence not ideal for this couple

Answer 505

B. Furosemide is one of the common causes of drug fever A - DRESS (drug reaction with eosinophilia and systemic symptoms), is often accompanied by eosinophilia and also by lymphadenopathy, which can be extensive C - Factitious fever (fever artificially induced by the patient—for example, by IV injection of contaminated water) should be considered in all patients but is more common among young women in health-care professions. D - In fraudulent fever, the patient is normothermic but manipulates the thermometer. Simultaneous measurements at different body sites (rectum, ear, mouth) should rapidly identify this diagnosis. Another clue to fraudulent fever is dissociation between pulse rate and temperature.

Answer 506

A. Do a fundoscopic examination

Answer 507

A. The basic reproduction number is higher than that of influenza A A - The basic reproduction number (R0 ) (the expected number of cases generated directly by one case in a population in which all individuals are susceptible to infection) of SARS-CoV-2 has been estimated to be between 5 and 6, which is substantially higher than that of seasonal influenza (typically 1–2). B - Airborne transmission by small particle from person-to-person may occur, but airborne transmission over long distances is unlikely. C - Densely populated settings such as prisons, cruise ships, nursing homes, airplanes, and large indoor gatherings facilitate even higher transmission efficiency. D - Advanced age is the principal risk factor for severe illness from COVID-19 (marked by need for hospitalization, intensive care, and mechanical ventilation)

Answer 508

B. Penicillin G Erysipelas is due to S. pyogenes and is characterized by an abrupt onset of fiery-red swelling of the face or extremities. The distinctive features of erysipelas are well-defined indurated margins, particularly along the nasolabial fold; rapid progression; and intense pain. Flaccid bullae may develop during the second or third day of illness, but extension to deeper soft tissues is rare. Treatment with penicillin is effective; swelling may progress despite appropriate treatment, although fever, pain, and the intense red color diminish.

Answer 509

B. History of Type 2 Diabetes Mellitus Given the clinical vignette, the patient seems to have cellulitis. Cellulitis caused by Streptococcus agalactiae (group B Streptococcus) occurs primarily in elderly patients and those with diabetes mellitus or peripheral vascular disease

Answer 510

A. Extend Ceftriaxone to 42 days of treatment Given the clinical vignette, the patient seems to have nontyphoidal salmonellosis. Preemptive antibiotic treatment should be considered for patients at increased risk for invasive NTS infection, including neonates (probably up to 3 months of age); persons >50 years of age with known or suspected atherosclerosis; and patients with immunosuppression, cardiac valvular or endovascular abnormalities, or significant joint disease. If the patient has endocarditis or arteritis, treatment for 6 weeks with an IV β-lactam antibiotic (such as ceftriaxone or ampicillin) is indicated.

Answer 511

A. Ceftriaxone plus Doxycycline

Answer 512

D. Staphylococcal superinfection The most common infectious complication of varicella is secondary bacterial superinfection of the skin, which is usually caused by Streptococcus pyogenes or Staphylococcus aureus, including strains that are methicillin-resistant. Pneumonia is the most serious complication

Answer 513

B. Delay the MMR and varicella vaccines for at least 3 months after the blood transfusion and IVIg. After receiving IVIg, the passive immunity provided by the IgG antibodies can interfere with the effectiveness of live vaccines. The usual recommendation is to wait at least 3 months after receiving IVIg before administering a live vaccine. This is because IVIg can provide temporary immunity that might suppress the immune response to the live vaccine.

Answer 514

C. He should receive the HPV vaccine, as it is recommended for immunocompromised individuals, including those with HIV. The CDC recommends that HIV-positive individuals aged 9–26 years receive the HPV vaccine. For those aged 27–45, the vaccine may still be considered if they are at risk for new HPV infections, which includes those with multiple sexual partners, as in this patient's case

Answer 515

C. Mucorales; initiate amphotericin B and consider surgical debridement.

Answer 516

A. Perform a bronchoalveolar lavage with staining for Pneumocystis organisms. Given the clinical vignette, the patient seems to have Pneumocystis pneumonia. Pneumocystis is an opportunistic pathogen that is an important cause of pneumonia in immunocompromised hosts, particularly those with HIV infection. The demonstration of organisms in bronchoalveolar lavage (BAL) fluid is almost 100% sensitive and specific for PCP in patients with HIV infection and is almost as sensitive in patients with immunosuppression due to other processes.

Answer 517

D. Most infected persons are asymptomatic except in epidemics A - Although diarrhea is common, upper intestinal manifestations such as nausea, vomiting, bloating, and abdominal pain may predominate B - Fever, the presence of blood and/or mucus in the stools, and other signs and symptoms of colitis are uncommon and suggest a different diagnosis or a concomitant illness. C - Symptoms tend to be intermittent yet recurring and gradually debilitating, in contrast with the acute disabling symptoms associated with many enteric bacterial infections. D - Most infected persons are asymptomatic, but in epidemics, the proportion of symptomatic cases may be higher

Answer 518

B. Larval penetration of avian schistosomes Given the clinical vignette, the patient seems to have cercarial dermatitis. Cercarial penetration of the skin may result in a maculopapular rash called cercarial dermatitis or “swimmer’s itch.” A particularly severe form of cercarial dermatitis is commonly seen after exposure to cercariae from avian schistosomes. These cercariae cannot complete their development in humans and die in the skin, causing an inflammatory allergic reaction.

Answer 519

B. Administer a single booster dose of rabies vaccine to maintain protection before his trip. Individuals who previously completed a full pre-exposure rabies vaccine series retain long-term memory immunity. However, antibody titers may wane over time, particularly in those with high-risk exposure. The World Health Organization (WHO) and the Advisory Committee on Immunization Practices (ACIP) recommend a single booster dose for individuals with continued or re-established high-risk exposure Preexposure rabies prophylaxis should be considered for people with an occupational or recreational risk of rabies exposures and also for certain travelers to rabies-endemic areas. The primary schedule consists of three doses of rabies vaccine given on days 0, 7, and 21 or 28. Serum neutralizing antibody tests help determine the need for subsequent booster doses. When a previously immunized individual is exposed to rabies, two booster doses of vaccine should be administered on days 0 and 3. RIG should not be administered to previously vaccinated persons.

Answer 520

D. Initiate treatment with multidrug therapy (MDT) for 12 months. Only one multidrug regimen is recommended by the WHO for the treatment of leprosy. This regimen consists of a combination of two or three of the following drugs: rifampin, dapsone, and clofazimine. The keystone of WHO-recommended multidrug therapy for multibacillary leprosy is a monthly dose of rifampin together with daily doses of dapsone and daily and monthly doses of clofazimine. Patients with paucibacillary leprosy are treated with two drugs, receiving monthly doses of rifampin and daily doses of dapsone. The treatment duration is 12 months for multibacillary disease and 6 months for paucibacillary disease

Answer 521

D. An immune complex-mediated syndrome Type 2 Leprosy Reaction (T2R), also known as ENL (erythema nodosum leprosum), is an immune complex–mediated syndrome (i.e., an antigen–antibody reaction involving complement) that causes inflammation of the skin, nerves, and other organs as well as general malaise. A - Applicable for type 1 leprosy reaction (T1R) B - ENL is an example of a type III hypersensitivity reaction (Coombs and Gell classification) or Arthus phenomenon

Answer 522

B. The increase in vascular permeability is associated with immune activation and cytokine response. Given the clinical vignette, the patient seems to have severe dengue (previously called dengue hemorrhagic fever and dengue shock syndrome). Severe dengue is associated with a transient increase in vascular permeability due to endothelial dysfunction in the critical phase. The induction of vascular permeability and shock depends on multiple factors, such as the presence or absence of enhancing and non-neutralizing antibodies, age (susceptibility to severe dengue drops considerably after 12 years of age), sex (females are more often affected than males), race (whites are more often affected than Black people), nutritional status, and timing and sequence of infections (e.g., dengue virus 1 infection followed by dengue virus 2 infection seems to be more dangerous than dengue virus 4 infection followed by dengue virus 2 infection). A - The extravasation of plasma into extravascular sites heralding DSS occurs during the critical phase C - The shock state occurs commonly among individuals infected with secondary DF infection D - There is no correlation between the degree and duration of fever to the propensity for DSS

Answer 523

A. Give PNSS at 5-7ml/kg/hour for 1-2 hours, then reassess Patient is already tachycardic despite being afebrile --> could be a sign of hemodynamic instability Initial IVF rate: 5-7mL/kg/hr for 2-4 hrs ● If improving, decrease to 3-5mL/kg/hr for 2-4 hrs ● If improving, decrease to 2-4mL/kg/hr Most patients with shock respond promptly to close monitoring, oxygen administration, and infusion of crystalloid or—in severe cases—colloid.

Answer 524

D. Urine PCR and Urine Culture Given the clinical vignette, the patient seems to have leptospirosis and is on the 2nd week of illness. A definitive diagnosis of leptospirosis is based on isolation of the organism from the patient, on a positive result in the PCR, or on seroconversion or a rise in antibody titer. A and C - usually used in the 1st week of illness B - Preferably, a fourfold or greater rise in titer is detected between acute- and convalescent-phase serum specimens

Answer 525

C. Hypotension is the initial manifestation of ATN and can be managed by fluid resuscitation. Hypotension is associated with acute tubular necrosis, oliguria, or anuria, requiring fluid resuscitation and sometimes vasopressor therapy. A - Typical electrolyte abnormalities include hypokalemia and hyponatremia. Loss of magnesium in the urine is uniquely associated with leptospiral nephropathy. B - Acute kidney injury is common in severe disease, presenting after several days of illness, and can be either nonoliguric or oliguric D - Hemodialysis can be lifesaving, with renal function typically returning to normal in survivors.

Answer 526

D. No treatment necessary, remove IFC

Answer 527

C. Elevated serum alkaline phosphatase Given the clinical vignette, the patient seems to have a liver abscess. Fever is the most common presenting sign of liver abscess. The single most reliable laboratory finding is an elevated serum concentration of alkaline phosphatase, which is documented in 70% of patients with liver abscesses. Other tests of liver function may yield normal results, but 50% of patients have elevated serum levels of bilirubin, and 48% have elevated concentrations of AST. Other laboratory findings include leukocytosis in 77% of patients, anemia (usually normochromic, normocytic) in 50%, & hypoalbuminemia in 33%

Answer 528

a. One dose of Tetanus diphtheria booster every 10 years B and C = already part of immunization during childhood D= px is > 26yo

Answer 529

c. Blood cultures taken upon admission and repeated daily until sterile Since organism is S. aureus, blood cs must be repeated daily until sterile then 4-6 weeks after

Answer 530

a. Plasmodium falcifarum

Answer 531

d. GBS should be considered as a differential diagnosis The patient presents with lower extremity weakness following a cat bite 1 month prior. This presentation is consistent with paralytic (dumb) rabies, a less common form of rabies that mimics neurological conditions like Guillain-Barré Syndrome (GBS).

Answer 532

a. Middle East respiratory syndrome may cause tropical hemorrhagic fever

Answer 533

c. Discontinue Oxacillin and start Clindamycin, Ampicillin and Ciprofloxacin Pain out of proportion --> necrotizing fascitis

Answer 534

a. Elevated lactate dehydrogenase and total protein Patients with rheumatoid arthritis have the highest incidence of infective arthritis (most often secondary to S. aureus) because of chronically inflamed joints; glucocorticoid therapy Specimens of peripheral blood and synovial fluid should be obtained before antibiotics are administered. Blood cultures are positive in up to 50–70% of S. aureus infections but are less frequently positive in infections due to other organisms. The synovial fluid is turbid, serosanguineous, or frankly purulent. Gram-stained smears confirm the presence of large numbers of neutrophils. Levels of total protein and lactate dehydrogenase in synovial fluid are elevated, and the glucose level is depressed; however, these findings are not specific for infection, and measurement of these levels is not necessary for diagnosis.

Answer 535

c. Biliary tract infection Case is liver abscess which is commonly from an underlying biliary tract infection

Answer 536

C. Amphotericin B

Answer 537

A. The causative agent can be cultured from punch biopsies of skin lesions

Answer 538

B. The toxin responsible for the disease is intra-axonally transported to the motor nuclei of the cranial nerves

Answer 539

B. Incubation period of 6 days Since <7 days Age >70 HR >140 No RR in poor prognosticators

Answer 540

B. Rash begins on the trunk and spreads to extremities and face

Answer 541

B. Desquamation of the involved skin occurs 5-10 days into the illness

Answer 542

D. Clostridium sordellii This postpartum patient presents with severe hypogastric pain, fever, vomiting, hypotension, tachycardia, and leukocytosis. The constellation of symptoms, particularly the absence of vaginal discharge and marked systemic signs, strongly suggests Clostridium sordellii toxic shock syndrome (CSTSS), a rare but life-threatening condition associated with postpartum or post-abortion sepsis.

Answer 543

A. P. aeruginosa This patient presents with sternoclavicular joint septic arthritis, a condition that is rare but more common in intravenous (IV) drug users. The key to effective management is identifying and treating the likely causative pathogens.

Answer 544

D. Vancomycin Cover for mrsa

Answer 545

C. The vaccine may compromise the ability to evoke immune response The Zoster Vaccine Live (ZVL) is a live attenuated vaccine used to prevent shingles (herpes zoster) in older adults. In the context of severe illness, the precaution regarding its administration reflects concerns about the immune system's ability to respond effectively to the vaccine, rather than the risk of a severe adverse reaction.

Answer 546

B. Maintain the current dose of Vancomycin AUC : MIC of >400 is adequate

Answer 547

C. Start Ceftazidime for empiric Pseudomonal coverage

Answer 548

A. Caspofungin

Answer 549

B. Let’s revisit other possible diagnosis aside from TB If fever still persists after 6 weeks of anti TB tx , consider other dx

Answer 550

C. Blood transfusion

Answer 551

B. Elderly

Answer 552

C. Pulmonary Aspergillosis This patient, with multiple myeloma, has a history of pulmonary tuberculosis (PTB) successfully treated with a susceptible regimen. His persistent symptoms of chronic cough, fatigue, and weight loss, coupled with CT findings of cavitary lesions and ground-glass opacities, raise suspicion for a secondary fungal infection, particularly chronic pulmonary aspergillosis (CPA).

Answer 553

D. Asymptomatic cyst carriage

Answer 554

B. RPR RPR (Rapid Plasma Reagin): A non-treponemal test, it is used for initial screening of syphilis due to its high sensitivity during secondary syphilis (90–100%). It detects antibodies against cardiolipin-lecithin-cholesterol antigens, which are elevated during active infection. Positive results should be confirmed with a treponemal-specific test (e.g., FTA-ABS or TP-PA). Similar to RPR, VDRL is a non-treponemal test. While it can also detect syphilis, RPR is more commonly used for screening due to its ease of performance and rapid turnaround time.

Answer 555

A. Cause has not been established but hematogenous spread of organisms in a patient with diseased liver is suggested Why other options are wrong B. Abdominal pain is the most common clinical manifestation --> FEVER C. A finding of ascitic fluid WBC >250/uL is diagnostic --> PMN D. Carbapenem is a drug of choice for antibiotic naïve individuals --> 3rd gen cephalosporin

Answer 556

B. 2D Echo Splenic abscess is associated with endocarditis

Answer 557

B. Ciprofloxacin Fully susceptible --> FQ

Answer 558

A. Nephrectomy

Answer 559

d. ≥5 WBC/HPF on urinalysis and 105 CFU/mL on urine culture

Answer 560

b. 2 doses of tetanus toxoid 4 weeks apart

Answer 561

c. 1 dose rabies Ig and post rabies vaccine until Day 7 Both rabies vaccine and Rabies Ig are safe during pregnancy and do not harm the fetus

Answer 562

d. Rabies virus spreads centripetally along the peripheral nerves via retrograde axonal transport

Answer 563

b. 4 months after rabies Ig

Answer 564

a. Plasmodium falciparum Infected young RBCs with black pigment are characteristic of P. falciparum. The black pigment is hemozoin, a byproduct of hemoglobin digestion by the parasite.

Answer 565

d. Coagulase-negative staphylococci This patient presents with symptoms suggestive of prosthetic valve endocarditis (PVE), including intermittent fever, shortness of breath, easy fatigability, bipedal edema, and a new systolic murmur, 8 months after valve replacement surgery. The likely etiologic agent depends on the timing of presentation following surgery. Classification of Prosthetic Valve Endocarditis: Early PVE: Occurs within 60 days post-surgery. Caused primarily by Staphylococcus aureus, coagulase-negative staphylococci, and Gram-negative bacilli due to surgical contamination. Late PVE: Occurs >60 days post-surgery (as in this case, 8 months after surgery). Typically caused by low-virulence organisms like: Coagulase-negative staphylococci (e.g., Staphylococcus epidermidis): A common cause of late PVE, particularly in prosthetic valves. Viridans streptococci and HACEK organisms.

Answer 566

a. No need for prophylaxis

Answer 567

c. in 2-3 days The onset of disease is heralded by pain within the dermatome, which may precede lesions by 48–72 h; an erythematous maculopapular rash evolves rapidly into vesicular lesions. In the normal host, these lesions may remain few in number and continue to form for only 3–5 days

Answer 568

b. Clostridial Myonecrosis

Answer 569

b. True gonococcal septic arthritis is less common than disseminated gonococcal infection (DGI) and always follows DGI

Answer 570

a. E. coli

Answer 571

a. Procalcitonin

Answer 572

Proteus, Pseudomonas, Serratia, Enterobacter, yeast

Answer 573

Urine CS Acute leptospiremic phase 3-10 days Immune phas coincides with disappearance oof leptospires in the blood

Answer 574

e. All of the above

Answer 575

b. Biopsy of the skin lesions will show vasculitis with many lymphocytes and PMNs Type 2 Lepra reaction A and C: describes Type 1

Answer 576

d. A and B ulnar, posterior auricular, peroneal, posterior tibial

Answer 577

e. All of the above Typhoid fever typically causes leukopenia (low WBC count), unlike most bacterial infections that present with leukocytosis. While Salmonella typhi is shed in the stool, stool cultures may be negative early in the disease (during the first week). The organism is more reliably detected in blood culture in the first week and in bone marrow culture (which has the highest yield). "Rose spots" are caused by S. typhi invading capillaries in the skin. A punch biopsy of these lesions can yield a positive culture for the organism.

Answer 578

e. Shift to Ceftriaxone 2-3 g IV q24h for 7 days Ceftriaxone is the safest and most effective option in pregnancy.

Answer 579

c. Single course of 1st line IV or PO antibiotic therapy for 7 days followed by 6-12 weeks of cotrimoxazole, schedule for surgery 1st line (CIP) then TMP SMX (6-12 weeks; gallstone is risk for chronic carrier state) if with anatomic abnormality (biliary / kidney stone): abx + surgery

Answer 580

d. Females are more commonly affected than males Severe Dengue - Monocyte infection - Risk factors: enhancing nonneutralizing antibodies (mother to baby) age (< 12 yo), females, caucasans, type 1 --> 2 > type 4 --> 2, TYPE 2 (most dangerous) !!!! malnutrition is protective

Answer 581

d. It generally presents with arthritis and rash Chikungunya - SS + RNA - Vector: Aedes aegypti and albopticus - Similar to dengue but no hemorrhagic fever - migratory polyarthritis and maculopapular rash (does nodesquamate) - MILD THROMBOCYTOPENIA

Answer 582

c. In the CNS the virus replicates almost exclusively at the white matter should be grey matter

Answer 583

a Lower extremity paralysis Paralytic rabies presents with quadriplegia

Answer 584

c. Diagnosis of Falciparum malaria in patients who have taken anti-malarial drugs

Answer 585

e. All of the above

Answer 586

d. WBC of 15,000/uL Since > 12k a. LDH 3-fold elevated from upper limit of normal --> AST/ALT b. Serum blood glucose of 70mg/dL --> <40 c. Serum creatinine of 200 umoL/L --> >265 e. Arterial pH of 7.35 --> <7.25

Answer 587

b. Worms generally multiply within human hosts Maturation only

Answer 588

e. All of the above

Answer 589

d. A and B No cirrhosis in Schistosoma Early change: hepatomegaly --> correlates with intensity of infection Due to granumalatous lesions Presinusoidal obstruction --> portal HTN and splenomegaly Periportal fibrosis--> Symmers clay pipe stem fibrosis

Answer 590

b. Blood 1st week: blood latter 1st week: CSF 2nd week and beyond: urine After 10 days --> immune phase --> urine

Answer 591

c. Proximal renal tubules reservoir: brain, kidney, eyes

Answer 592

a. Interstitial nephritis and tubular necrosis with renal failure contributed by dehydration and altered capillary permeability B--> focal necrosis only C--> pulmo hemorrhage

Answer 593

a. Onset of illness is similar to anicteric leptospirosis but with earlier occurrence of jaundice, renal and vascular complications Profound jaundice but no severe necrosis Renal failure 2nd week of illness MC death: pulmonary hemorrhage

Answer 594

d. A and C Dont give loperamide since infetious C diff infection Tx: stop abx; hydrate Give oral vanco or MTR

Answer 595

A. Rifampicin and Streptomycin

Answer 596

D. Atrial fibrillation Altered mental status Respiratory insuiciency (rales, inltrates) Hemoptysis Oliguric hyperkalemic acute renal failure Cardiac involvement (myocarditis, complete or incomplete heart block, AF)

Answer 597

C. 30/M with hemoptysis and hypoxemia

Answer 598

C. Ceftriaxone 2 g IV Q24H x 14 days

Answer 599

B. MDRTF should be suspected if a patient fails to respond after 5 days of appropriate first line therapy

Answer 600

C. Critical phase coincides with defervescence and rise in hematocrit Leukopenia is the earliest abnormality in CBC starts in the febrile phase Thrombocytopenia precedes signs of plasma leakage Viremia coincides with the peak of fever and critical phase coincides with defervescence and rise of hematocrit. Platelet count generally recovers later than WBC count.

Answer 601

D. Transfuse packed RBCs

Answer 602

D. Watch out for heavy menstrual bleeding

Answer 603

C. Mycoplasma pneumonia is treated for 10 to 14 days

Answer 604

D. Nasogastric tube without active drainage

Answer 605

D. Plasmodium malariae P. falciparum is the predominant species in the Philippines and is responsible for almost all deaths and neurologic complications from malaria P. vivax causes benign tertian malaria The correct answer is: Plasmodium malariae

Answer 606

B. 32/F with serum lactate of 5.2 mmol/L

Answer 607

B. Empiric coverage for Gram positive cocci and Gram negative aerobic bacilli

Answer 608

C. Defervescence can be expected 48 hours after percutaneous drainage of intraabdominal abscesses. Drainage is the mainstay therapy for intraabdominal abscesses Splenic abscesses are much lesscommon than liver abscesses. Defervescence can be expected 48 hours after percutaneous drainage of intraabdominal abscesses. The most important risk factor for developing perinephric abscess is obstructing urolithiasis.

Answer 609

D. 12 weeks

Answer 610

B. Doxycycline 100 mg PO BID

Answer 611

C. Clindamycin + Ampicillin + Ciprofloxacin Clindamycin + Penicillin G is the primary treatment for necrotizing fasciitis caused by group A streptococci. Clindamycin + 1 generation cephalosporin is the alternative. Vancomycin + Metronidazole + Ciprofloxacin is the alternative treatment for necrotizing fasciitis from mixed aerobes and anaerobes.

Answer 612

C. Blood cultures are not routinely recommended except in patients with sepsis Urinalysis shows pyuria of >5 WBC/hpf Urine culture shows at least 100,000 cfu/mL of uropathogens. Blood cultures are not routinely recommended except in patients with sepsis Procalcitonin, mid-regional pro-ANP, or CRP are not useful in determining need for admission and predicting adverse outcomes

Answer 613

C. Both A and B are appropriate

Answer 614

D. HIV testing and counseling Presumptive therapy must be initiated based on risk prole even without diagnostic results CSF analysis for neurosyphilis is recommended for PLHIV with any stage of syphilis HIV testing and counseling is recommended for all patients with genital ulcers.

Answer 615

A. Bacterial pneumonia

Answer 616

D. It is frequently seen in the seing of tuberculosis, when ART is started soon after TB therapy ParadoxicalIRIS involves worsening of a known preexisting infection or neoplasm It occurs weeks to months following initiation of antiretroviral therapy It is more common among PLHIVs with CD4 counts below 50 per microliter who experience a precipitous drop in viral load

Answer 617

A. Clinical findings Diagnosis of tetanus is clinical. Treatment should not be delayed while laboratory tests are conducted Culture of C. tetani from a wound provides supportive evidence Serum anti-tetanus immunoglobulin G also may be measured in a sample taken before the administration of antitoxin or immunoglobulin Polymerase chain reaction also has been used for detection of tetanus toxin, but its sensitivity is unknown

Answer 618

C. TIG + Tetanus toxoid

Answer 619

C. Prophylactic antibiotics an hour prior to surgery, discontinue within 24 hours

Answer 620

B. Yeast Same goes with HBV

Answer 621

D. The Southern hemisphere strain is recommended in the Philippines Available as trivalent and quadrivalent Given intramuscularly Recommended for PLHIV regardless of CD4 count

Answer 622

D. Klebsiella pneumoniae

Answer 623

A. Thoracic surgery

Answer 624

A. Praziquantel 40 mg/Kg PO in 2 divided doses x 1 day S. haematobium B is for S. japonicum and mekongi

Answer 625

B. Diethylcarbamazine is recommended for treatment Lymphedema is caused by granulomatous host response to non-viable adult worms Mansonia and Anopheles mosquitoes serve as the vector for Brugia malayi Adult Wuchereria bancrofti worms are found in lymphatic tissue

Answer 626

C. Demonstration of Entamoeba histolytica cysts

Answer 627

A. Iodoquinol

Answer 628

D. Tests may need to be repeated after an interval for diagnostic confirmation Patients present with acute atypical encephalitis or flaccid paralysis Hydrophobia is not usually present Skin biopsy samples from the neck is diagnostically useful Tests may need to be repeated after an interval for diagnostic confimation

Answer 629

A. Foodborne botulism

Answer 630

B. Passive leg raids to assess volume status

Answer 631

C. Blood culture before antibiotic administration

Answer 632

A. Isoniazid