Infectious Disease Flashcards
Clinical clues for Legionella Pneumonia
- Recent travel (especially cruise or hotel stay) within the previous 2 weeks
- Contaminated potable water in hospitals/nursing homes
- Fever > 102.2
- Bradycardia relative to high fever
- Neurological symptoms (especially confusion)
- GI symptoms (especially diarrhea)
- Unresonsive to beta-lactam and aminoglycoside antibx
Laboratory clues for legionella pneumonia
- Hyponatremia
- Heptatic dysfunction
- Hematuria and proteinuria
- Sputum Gram stain showing many neurtrophils but few or no microorganisms
Most common method used to confirm diagnosis of Legionnaires’ disease
urine antigen testing
When Legionnaires’ dz is suspected or proven, what therapy should be started
-Macrolide or fluoroquinolone
Describe the CSF findings in Cryptococcal meningoencephalitis
- High opening pressure (normal: 100-180 mm H20)
- Low glucose, High protein
- WBC < 50/uL with mononuclear predominance
- Transparent capsule seen with india ink stain
- Cryptococcal antigen positive
- Culture on Sabouraud agar
Describe the treatment of Cryptococcal meningoencephalitis?
- Initial: Amphotericin B with Flycytosine
- Maintenance: Fluconazole
Cryptococcal meningoencephalitis is typically seen in immunocompromised patients, especially those with advance HIV disease at what CD4 count
< 100
This is used to treat dermatophytosis and onychomycosis?
Griseofulvin
Patient with thrush and an opportunistic infection such as Cryptococcus suggest that the patient is immunocompromised. HIV is a common and treatable cause of immunosuppression in this patients age group. Describe the testing and treatment of the HIV in the setting of acute infection?
- She should be tested for HIV, but initiation of antiretroviral therapy in the setting of acute infection is not recommended due to risk of immune reconstitution syndrome
- Antiretroviral therapy should be deferred until at least 2-8 weeks after completing induction antifungal therapy for crytpococal meningitis (this was just specific for this infection)
Describe the use of Itraconazole in treating Cryptococcal infection
- Can be used as on alternate to fluconazole in the treatment of pulmonary cryptococcal infection.
- However, it does not cross the BBB, making it ineffective in CNS infection
This is used in the treatment of cerebral toxoplasmosis, which typically presents with headache, focal neurologic deficits, and/or seizures. Neuroimaging shows multiple ring-enhancing lesions with edema
Sulfadiazine-pyrimethamine
Manifestation of Primary syphilis?
-Painless genital ulcer (chancre)
Manifestation of Secondary Syphilis?
- Diffuse rash (palms and soles)
- Lymphadenopathy (Epitrochlear**)
- Condyloma lata
- Oral lesions **
- Hepatitis
Manifestation of Latent syphilis
Asymptomatic
Manifesation of Tertiary Syphilis
- CNS (Tabes Dorsalis, Dementia)
- Cardiovascular (Aortic aneursym/insufficiency)
- Cutaneous (gummas)
Describe the oral mucosa lesions in secondary syphilis?
-grey mucous patches
Describe the rash seen in secondary syphilis
A diffuse maculopapular rash that begins on the trunk, extends to the extremities, and involves the palms and soles
The presence of EPITROCHLEAR lymphadenopathy is particularly pathognomonic for what?
secondary syphilis
Describe the diagnosis and treatment of syphilis
- Diagnosed using a combo of nontreponemal (eg, RPR) and treponemal-specific (eg, T pallidum enzyme immnoassay) serologic tests.
- Treatment for secondary syphilis is the same as for primary syphilis - one dose of IM penicillin G benzathine - which provides up to 3 weeks of treatment-dose penicillin.
- Adequate treatment is confirmed by a 4-fold decrease in serologic titers at 6-12 months
Patients who receive solid organ transplantation require high-dose immunosuppressant meds to prevent rejection. This creates an immunocompromised state that puts patients at high risk for opportunistic infections, most notable Pneumocystis pneumonia (PCP) and CMV. Post-transplant patients with PCP typically have acute respiratory failure (tachypnea, hypoxia), dry cough, and fever (the course is more indolent in patients with HIV). Lactate dehydrogenase levels are often elevated, and chest x-ray classically reveals bilateral, diffuse interstitial infiltrates. Describe how you yield this diagnosis
- P jirovecii (The causative organism of PCP) cannot be cultured
- Diagnosis requires the examination of respiratory samples using microscopy with specialized stains
- Induced sputum is the least invasive method for obtaining an adequate respiratory samples.
- If this does not yield a diagnosis, bronchoscopy with bronchoalveolar lavage*** is required
Beta-D-glucan is part of the cell wall of fungi; therefore, a serum assay can be useful in the diagnosis of many fungal infection. Particularly which ones?
- Aspergillus
- Candida
What organism?
- AIDS with CD4 < 180
- Severe, watery diarrhea **
- Low-grade fever
- Weight loss
Cryptosporidium
What organism?
- AIDS with CD4 < 100
- Watery diarrhea
- Crampy abdominal pain
- Weight loss
- Fever is RARE**
Microsporidium/isosporidium
What organism?
- AIDS with CD4 < 50
- Watery diarrhea
- HIGH FEVER (> 102.2)
- Weight loss
Mycobacterium avium complex
What organism?
- AIDS with CD4 < 50
- Frequent, small volume diarrhea
- Hematochezia
- Abdominal pain
- Low-grade fever
- Weight loss
CMV
Cryptosporidium is among the most common causes of infectious diarrhea worldwide and is commonly spread how?
- Through drinking water
- Animal contact (eg, horse breeding)
- Person-to-person contact
What does stool examination show is cryptosporidium infection and what is treatment (especially in AIDS)
- Stool examination with modified acid-fast stain reveals cryptosporidial oocytes measuring 4-6 um
- The mainstay of treatment is supportive care and antiretroviral therapy because infection often persists until CD4 counts improve
How does Entamoeba histolytica infection present?
Dysentery, which is characterized by abdominal pain, diarrhea, and bloody stools
Strongyloides stercoralis infxn is associated with what presentation?
- Cutaneous (pruritus and urticaria)
- Pulmonary
- GI
Acute Pyelonephritis can result in Gram-negative sepsis. Urine (and blood) cultures should be obtained routinely before administration of empiric antibiotics. When is urological imaging (eg, CT of abdomen/pelvis) indicated?
- typically reserved for patients with persistent clinical symptoms despite 48-72 hours of therapy
- History of nephrolithiasis
- complicated pyelonephritis (abscess, multiorgan failure, shock, renal failure, MOre likely in DM, kidney stones, immunosuppression, or anatomic abnormalities)
- Unusual urinary findings (eg, gross hematuria, suspician for urinary obstruction)
Pathogenesis of C. Diff colitis
- Disruption of intestinal flora –> C difficile overgrowth
- Exotoxins cause mucosal inflammation/injury
Most common clinical presentation of C. diff colitis?
-WATERY diarrhea
Diagnosis and treatment of C. diff colitis
- Stool PCR (stool toxin testing)
- ORAL Vancomycin or metronidazole
Stool cultures are NOT highly diagnostic in patients who develop diarrhea after >72 hours of hospitalization. They can be helpful in what situations?
- Immunocompromised patients
- Those with bloody diarrhea or underlying IBD to distinguish between disease flare and infection
Nonspecific systemic symtptoms (eg, fever, cough, abdominal pain, diarrhea, night sweats, weight loss) in the presence of SPLENOMEGALY and an elevated ALK PHOS level should raise suspicion for what in patients with HIV and a CD4 count < 50?
- Disseminated Mycobacterium avium complex (MAC)
- The splenomegaly and alk phos reflect MAC hepatosplenic involvement
Diagnosis, Treatment and Prophylaxis of MAC infection in HIV patients?
- Diagnosis: blood cultures (or lymph node or bone marrow biopsy)
- Treatment: first line is clarithromycin or azithromycin
- Patients with CD4 count < 50 should receive Azithromycin prophylaxis against MAC
Prophylaxis of Pneumocystis pneumonia in HIV
- Trimethoprim-sulfamethoxazole is preferred
- Dapsone is alternate
This can be considered as prophylaxis in patients with HIV who have had episodes of esophageal candidiasis?
Fluconazole
What organism?
- Gram-negative, free-living in MARINE environments
- Ingestion (oysters) or wound infection
- Increased risk in those with LIVER disease ** (cirrhosis, hepatitis, hemochromatosis)
Vibrio Vulnificus
Describe the manifestations of Vibrio Vulnificus infection
- Rapidly progressive (often < 12 hours)
- Septiciemia (septic shock, BULLOUS lesions)
- Cellulitis: HEMORRHAGIC BULLAE, necrotizing fasciitis
Why are those with hemochromatosis at particularly great risk of getting Vibrio vulnificus infection?
free iron act as an exponential growth catalyst
Describe diagnosis and treatment of Vibrio vulnificus infection
- Diagnosis is made by blood and wound cultures
- Treatment (IV antibiotics) should NOT BE DELAYED due to high risk of DEATH
Describe how you diagnose CMV colitis in HIV patient with CD4 < 50
- The diagnostic test of choice is a colonoscopy with biopsy (eosinophilic intranuclear and basophilic intracytoplasmic inclusions)
- Serology and PCR results may be positive but do NOT conclusively prove end-organ disease (eg, colitis)
What is the most likely diagnosis in a patient from Mississippi who was initially thought to have sarcoidosis (cough, hilar adenopathy, erythema nodosum, and non-caseating granulomas in an African American individual) but deteriorates following high-dose corticosteroid therapy
Histoplasmosis
What is used for diagnosis of Histoplasmosis
-Careful fungal tissue stains and culture, along with Histoplasma urinary antigen testing
Blastomyces (associated with contact with soil or rotting wood, with dissemination in immunocompromised hosts presenting as skin lesions, osteolytic bone lesions, or prostate involvement) is also present in Mississippi and should be excluded in a patient with suspected histoplasmosis. What symptom is more suggestive of histoplasmosis?
Hilar adenopathy
Where is coccidioides found
SOUTHWESTERN US
Postherpetic neuralgia is persistent neuritic pain > 4 months after Herpes Zoster rash onset. What is treatment?
-TCAs, Pregabalin, Gabapentin
This is used in the treatment of drug-resistant CMV. It can also be considered for patients with severe VZV who fail first line drugs
Foscarnet
Doxycycline is an excellent treatment option for lyme disease as it has the advantage of simultaneously preventing or treating coexisting what?
human granulocytic anaplasmosis, an infection also carried by I. scapularis
Ludwig angina is a rapidly progressive cellulitis of the submandibular space. Most cases arise from what?
-Dental infections in the mandibular molars that spread contiguously down the root into the submylohyoid (and then sublingual) space
Describe how someone with Ludwig angina presents
- develops symptoms rapidly with systemic (fever, chills, malaise) and local compressive (eg, mouth pain, drooling, dysphagia, muffled voice, airway compromise) manifestations
- Physical exam findings are often striking due to mass effect from edema
- The submandibular area is usually tender and indurated, and the floor of the mouth is often elevated, displacing the tongue
- Anaerobic, gas-producing bacteria may cause crepitus
Diagnosis and treatment of Ludwig angina
- CT scan of the neck confirms the diagnosis and rules out an abscess
- Most patients are treated with IV antibiotics (eg, ampicillin-sulbactam, clindamycin) and removal of the inciting tooth
- Drainage and surgery are rarely required as the process is cellulitic and typically nonsuppurative
- Impaired respiratory status requires prompt attention and early intervention with a mechanical airway
Lymph nodes can rarely cause an airway obstruction in Tuberculosis lymphadenitis . .what is this called?
Scrofula
Describe the use of serology in the diagnosis of Lyme disease
- Serology is NOT recommended in early localized disease as it is too insensitive and many patientss would be seronegative
- After the onset of erythema migrans, IgM antibodies to B burgdorferi usually appear within 1-2 week, and IgG antibodies typically appear within 2-6 weeks
- However, serology should be performed in patients with signs of early disseminated or late Lyme disease
HIV-associated diarrhea has many potential causes. CD4 count, chronicity, and the presence or absence of symptoms of colitis help narrow the differential diagnoses. Workup typically begin how?
-sending the stool for several tests including culture, ova and parasites, acid-fast stain, and C diff. antigen
Patients with pneumonia caused by anaerobic organisms typically present with indolent symptoms such as fever, malaise, and a characteristic foul-smelling sputum. Poor dentition, which predisposes to a greater quantity of oral anaerobic organisms, increases risk for anaerobic aspiration pnemonia. Other risk factors for aspiration include forms of upper airway instrumentation (eg, endotracheal or nasogastric tubes), GERD, dysphagia, and impaired consciousness . . describe the antibiotic manageent
- Clindamycin
- Metronidazole with amoxicillin
- Amoxicillin-Clavulonate
- Carbapenem
Describe the epidemiology of Acute epididymitis?
- Age <35: Sexually transmitted (chlamydia, gonorrhea)
- Age > 35: Bladder outlet obstruction (coliform bacteria)
- Unilateral testicular pain
- Epidiymal edema
- Dysuria, frequency (with coliform infection)
Acute Epididymitis
Describe the likely causative organism of Acute Epididymitis based on Age
- Those Age > 35: Ascending coliform bacteria such as E. coli are most likely and urinary tract inflammatory symptoms (eg, dysuria, frequency are common)
- Patients age < 35: Chlamydia, N. gonorrhoeae
Describe the treatment of Acute Epididymitis
- Ceftriaxone/Doxycycline (if STI)
- Levofloxacin (if coliform bacteria)
Staph aureus can cause epidiymitis or orchitis in what setting?
-In the setting of a surgical procedure or severe overlying skin infections but is otherwise unlikely
This usually presents with the classic triad of fever, leukocytosis, and left upper-quadrant abdominal pain. Patients can also develop left-sided pleuritic chest pain, left pleural effusion, and splenomegaly
Splenic abscess
What are the risk factors for splenic abscess
- Infection (eg, infective endocarditis) with hematogenous spread
- Immunosuppression
- IV drug use
- Trauma
- Hemoglobinopathies
Treatment of splenic abscess
- Combination of broad-spectrum antibiotics and splenectomy
- Possible percutaneous drainage in poor surgical candidates
A patient with elevated transaminases, hepatomegaly and a positive serology test for hepatitis C virus (HCV) antibody (suggesting likely exposure to HCV) should undergo testing to confirm the diagnosis of chronic HCV infection. Describe this diagnostic process
-Because the virus may spontaneously clear in up to hald of affected patients, Diagnosis of chronic infection is a 2-step process that require both a positive serologic test for the HCV antibody and a confirmatory molecular test for the presence of circulating HCV RNA
In patients with esablished HCV, what imaging surveillance is needed and why?
-Abdominal U/S repeated every few months is recommended forsurveillance for hepatocellular carcinoma
This is an uncommon inflammatory disorder characterized by recurrent high fevers, arthritis/arthralgias, and a salmon-colored macular or maculopapular rash. ESR may be markedly elevated
Adult Still disease
Describe the manifestation of the immunologic phenomena that comes from infective endocarditis
- Positive Rheumatoid factor (possibly due to antibody production)
- Immune complex-mediated glomerulonephritis (hematuria, red cell casts)
- Cutaneous manifestations: Osler nodes (painful fingertip nodules)
What do lab studies usually show in infective endocarditis
- normocytic anemia
- dramatic elevations in ESR
Describe the clinical features of Mycoplasma pneumonia
- Indolent headache, malaise, fever, persistent dry cough
- Pharyngitis (NONexudative)
- Macular/vesicular rash **
diagnostic findings in mycoplasma pneumonia
- Normal leukocyte count
- Subclinical hemolytic anemia (cold agglutinins)
- Interstitial infiltrate (chest x-ray)
- A serous pleural effusion may be present in approximately 25% of patients
Risk factors for Neisseria gonorrhoeae infection are shared with many other STIs and include age <25, new or multiple sexual partners, substance abuse, and men who have sex with men. Coinfection with multiple pathogens is common; rates of simultaneous gonococcal and Chlamydia trachomatis infection are as high as 40% (Azithromycin also treats chlamydia). What other pathogens should a patient with gonorrhoaea be screens for?
- HIV
- Syphilis
- Hep B
Most common cause of community-acquired bacterial meningitis?
- Strep pneumo
- is usually secondary to hematongenous dissemination and may occur with or without concurrent pneumococcal pneumonia
Individual with a history of high risk sexual intercourse should be screened for HIV and hepatitis B. Who should be screened for hepatitis C?
- IV drugs users
- those with high risk needlestick exposure
- those who received blood transfusion before 1992
This is primarily seen in patients with HIV with CD4 counts <100. Symptoms feature vascular cutaneous lesion that often begin as small reddish/purple papules that evolve into friable pedunculated or nodular lesions. constitutional symptoms (eg, fever, malaise, night sweats) are typically present and organ (Liver, CNS, bone) involvement may occur.
Bacillary angiomatosis (Bartonella)
Treatment of bacillary angiomatosis
- Antibiotics (doxy, erythromycin)
- initiation of antiretroviral therapy (usually 2-4 weeks later)
Diagnostic criteria for infective endocariditis is through the modified Duke criteria. Definitive diagnosis is with 2 major OR 1 major and 3 minor criteria. Possible diagnosis is with 1 major OR 3 minor criteria. What are the major criteria?
- Blood culture positive for typical microorganisms (eg, strep viridans, staph aureus, enterococcus
- Echo showing valvular vegetation
Diagnostic criteria for infective endocariditis is through the modified Duke criteria. Definitive diagnosis is with 2 major OR 1 major and 3 minor criteria. Possible diagnosis is with 1 major OR 3 minor criteria. What are the minor criteria?
- Predisposing cardiac lesion
- IV drug use
- Temp > 38 C (100.4 F)
- Embolic phenomena
- Immunologic phenomena (eg, glomerulonephritis)
- Positive blood culture not meeting major criteria
What should be done in all patients with suspected infective endocarditis prior to initiating antibiotic therapy?
blood cultures from separate venipuncture sites over a specified period
What HIV CD4 level is susceptible to Toxoplasma encephalitis
< 100
Toxosplasmic encephalitis show multiple ring-enhancing lesions of the brain on MRI with a preference for what location
Basal ganglia
Treatment of Toxoplasmic encephalitis?
- Several weeks of sulfadiazine and pyrimethamine (plus leucovorin to prevent hematologic side effects)
- Patients who are not on antiretroviral therapy should be initiated 2 weeks after beginning treatment
Neurocysticercosis is associated with pork consumption or travel to endemic areas (eg, Central and South America). It tends to cause seizures, and MRI of the brain usually reveals what?
a mixture of enhancing, nonenhancing, and calcified lesions (depending on the stage of the cyst)
Ganciclovir is used to treat CMV. CMV encephalitis is marked by confusion and focal neurologic deficits with evidence of what on MRI
multifocal micronodules or ventricular enhancement (ring-enhancing lesion very uncommon)
Catheter associated UTI is most effectively prevented by avoiding unnecessary catheter use and minimizing the duration of catheterization. However, in patients with neurogenic bladder, long-term catheter use is required. In these patients, What should be done?
-Clean intermittent catheterization, which involves periodic insertion and removal (eg, every 4-6 hours) of a clean urinary catheter and can often be performed by the patient
Patients with Pneumocystis pneumonia who do not have HIV (immunocompromised for some other reason) typically develop what symptoms?
- Acute respiratory failure (tachypnea, dyspnea, hypoxia with respiratory alkalosis)
- Dry cough
- fever
- The course is more indolent in patients with HIV
there is a strong association between infections with Strep Gallolyticus (S bovis biotype I) and what?
What further workup?
- colonic neoplasms
- Colonoscopy . . Not fecal occult blood testing as it is less sensitive and specific
The most common cause of bloody diarrhea in the absence of fever is what?
E coli
Treatment of EHEC
- generally supportive
- antibiotics are not helpful and may increase the risk of HUS
A PPD test is considered positive in an HIV-infected individual when induration is 5 or more mm at 48-72 hours. Active TB must then be ruled out with a chest x-ray (infiltrate, lymphadenopathy) and symptom review (night sweats, fevers, cough. Patients with no manifestation of active TB are treated for latent TB with what?
- 9 months of Isoniazid
- Pyridoxine is added to prevent isoniazid-induced peripheral neuropathy
patients with HIV may have false-negative PPD testing, especially with CD4 counts < 200. Describe the management?
-Should be retested after initiating antiretroviral therapy (and CD4 count rises >200)
Describe the management of a fight bite injury
- Amoxicillin-clavulanate is often the treatment of choice due to excesslent coverage of gram-positive, gram-negative, and beta-lactamase-producing oral anaerobic organisms (as clavulanate isa beta lactamase inhibitor)
- Surgical debridement is usually necessary and wounds are typically left open to drain and heal by secondary intention (due to high infection risk with closure
- Tetanus vaccination should be administered to those who are not up to date
Foot infections are common in patients with DM. Symptoms usually start with localized skin erythema, warmth, tenderness and edema. Deeper infections should be suspected in those with long-standing wounds (>1-2 weeks), systemic symptoms (fever, chills), large ulcer size (2 or more cm), elevated ESR, and the presence or palpation of bone in the ulcer base. Patients with any of these features almost always are infected by what organism?
-Polymicrobial infections with a mixture of gram-positive (eg, staph aureus, strep pyogenes), gram-negative (eg, pseudomonas aeruginosa), and anaerobic organisms
What bug in Infective endocarditis?
- Prosthetic valves
- IV catheters
- Implanted devices (eg, pacemaker/defibrillator)
- IV drug users
Staph aureus
What bug in Infective endocarditis?
- Gingival manipulation
- Respiratory tract incision or biopsy
-Viridans group streptococci
What bug in Infective endocarditis?
- Prosthetic valves
- IV catheters
- Implanted devices
Staph epidermidis
What bug in Infective endocarditis?
-Nosocomial UTIs
Enterococci
What bug in Infective endocarditis?
- Colon carcinoma
- IBD
strep gallolyticus (S bovis)
What bug in Infective endocarditis?
- Immunocompromised host
- IV catheters
- Prolonged antibiotic therapy
Fungi (eg, Candida)
What bugs are in Viridans strep species
- S. sanguinis
- S. mitis
- S. oralis
- S. mutans
- S. sobrinus
- S milleri
Arthritis due to parvovirus and RA involve similar joints so how do you differentiate Parvovirus B19?
- Acute onset
- Absence of joint swelling and prolonged stiffness in morning
Describe the arthritis of Rheumatic fever
-usually migratory and initially affects lower-extremity joints
Chlamydia trachomatis is a common cause of urethritis in men. It cannot be visualized in Gram-stained material or recovered in conventional culture. The diagnosis can be made how?
-nucleic acid amplification testing of a first-catch urine sample WITHOUT pre-cleaning the genital area
What are the 2 painFUL infectious genital ulcers?
- HSV
- Haemophilus ducreyi (chancroid)
What are the 2 painLESS infectious genital ulcers?
- Treponema pallidum (syphilis)
- Chlamydia trachomatis serovars L1-L3 (Lymphogranuloma venereum)
What infectious genital ulcer?
- Painful
- Small vesicles or ulcer on erythematous base
- mild lymphadenopathy
HSV
What infectious genital ulcer?
- Painful
- Larger, deep ulcers with gray/yellow exudate
- Well-demarcated border and soft, friable base
- Severe lymphadenopathy that is that may be suppurate
Haemophilus ducreyi (chancroid)
What infectious genital ulcer?
- Painless
- Single ulcer (chancre)
- Regular borders and hard base
Treponema pallidum (syphilis)
What infectious genital ulcer?
- Painless
- Small, shallow ulcers (often missed)
- Can progress to painful, fluctuant adenitis (buboes)
Chlamydia trachomatis serovars L1-L3 (lymphogranuloma venereum)
This is a deep form of impetigo that typically begins as a vesicle/pustule on an inflamed area of skin and then converts to an indurated, purulent ulcer. Lesions are most common on the buttocks, thighs, and legs
Staphylococcal ecthyma
Secondary bacterial pneumonia is the most common influenza complication and should be suspected when fever and pulmonary symptoms worsen after initial improvement. Most cases occur in patients age >65, but what organism has a predilection for young patients with recent influenza?
-Methicillin-resistant Staph aureus
Describe the pneumonia that community associated MRSA causes
- preferentially attacks young patients with influenza
- causes severe, necrotizing pneumonia that is rapidly progressive and often fatal
- Manifestations include high fever, productive cough with hemoptysis
- Leukopenia
- multilobar cavitary infiltrates
Nocardia is a filamentous, aerobic, gram-positive bacteria that is partially acid-fast. It causes pulmonary or disseminated disease (particularly to the brain) in immunocompromised hosts. What is the treatment?
- Trimethoprim-sulfamethoxazole
- When the brain is involved, the carbapenems are added for better coverage
- When possible, abscesses should be surgically drained as well
- Duration of therapy depends on the clinical response but is generally long (6-12 months)
Infectious esophagitis is common in patients with advanced HIV, especially with CD4 counts < 100. the most common cause of esophagitis in patients with HIV is Candida albicans (>60% of cases); however; viral esophagitis is more likely than candidal esophagitis in patients with what symptoms?
- Severe odynophagia (pain with swallowing) as the predominant symptom
- No dysphagia (difficulty swallowing)
- No thrush
Medication-related chemical esophagitis (“pill esophagitis”) can cause acute odynophagia due to direct effects of a medication on esophageal mucosa. Common offending medication include what?
- Potassium chloride
- Tetracyclines
- bisphosphonates
- NSAIDs
Acute HIV infection typically present 2-4 weeks after exposure. What are the clinical features?
- Mononucleosis-like syndrome (eg, fever, lymphadenopathy, sore throat, arthralgias)
- Generalized macular rash
- GI symptoms
Diagnosis of Acute HIV infection
- Viral load is markedly elevated (>100,000 copies/mL)
- HIV antibody testing may be NEGATIVE (not yet seroconverted)
- CD4 count may be normal
Patient presents with nonspecific symptoms with GI symptoms (diarrhea, abdominal distension, flatulence), accompanied by arthralgias, night sweats, weight loss, and lymphadenopathy. The differential diagnosis includes acute HIV infection, IBD, connective tissue diseases, lymphoma, and Whipple’s disease among others. What is the most appropriate first step?
- HIV testing
- A low threshold for HIV testing should be adopted
The response of acute hepatitis B infection depends heavily on when in life a patient becomes infected. Describe this?
- Patients infected during the perinatal period almost universally progress to chronic HBV infection
- Children age 1-5 have an intermediate response, with 50%-80% achieving spontaneous remission
- Among healthy adults, acute HBV infection is self-limited in > 95% of cases
Treatment of Rhino-orbital-cerebral mucormycosis
- Surgical debridement
- Liposomal amphotericin B
- Elimination of risk factors like high blood glucose and acidosis
Hepatitis A virus infection commonly presents with fever, nausea, vomiting, and abdominal pain followed by jaundice and pruritis. Physical exam and lab analysis reveals tender hepatomegaly and significant elevations in transaminases, bilirubin, and alkaline phosphatase. What is the most likely sequela?
Most patients completely recover in 3-6 weeks
This is marked by persistent fever, malaise, and fatigue with absolute lymphocytosis on CBC and atypical lymphocytes on peripheral blood smear. Unlike, Epstein-Barr virus, this is much less likely to cause pharyngitis, lymphadenopathy, or splenomegaly. Heterophile antibody test is negative
- CMV mononucleosis
- CMV IgM serology is positive
Describe the Epidemiology of Echinococcus granulosus?
- Dog tapeworm (sheep intermediate host)
- Rural, developing countries (eg, South America, Middle East)
- Humans are incidental hosts (egg ingestion)
Manifestations of Echinococcus granulosus
- Initially asymptomatic (often for years)
- LIVER CYST (most common): Mass effect causes RUQ pain, N/V, hepatomegaly; Rupture causes fever and eosinohilia
- Lung cyst: cough, chest pain, hemoptysis
Describe the diagnosis of Echinococcus granulosus
- Imaging: Large, smooth hydatid cyst often with internal septations
- IgG Echinococcus granulosus serology
Treatment of Echinococcus granulosus
- Albendazole
- Percutaneous therapy (> 5 cm or septations)
- Surgery (if rupture)
Undercooked fish may transmit liver flukes (eg, clonorchis sinensis) or fish tapeworm (eg, Diphyllobothrium latum) . .what does each of these cause?
- Liver flukes: biliary disease
- Fish tapeworms: rarely causes symptoms but may cause magaloblastic anemia due to vitamin B12 deficiency
Injection drug users, patients with sickle cell anemia, and immunosuppressed patients are at highest risk for osteomyelitis. The spine is a frequent site of osteomyelitic infection in injection drug users. Most cases of VERTEBRAL osteomyelitis are chronic (>6 weeks) and insidious with minimal symptoms. Describe what can be found
- Many patients have back pain unrelieved by rest
- fever is present <50% ***
- PE often shows new findings but tenderness to gentle percussion over the spinous process of the involved vertebra can be an important clue
- Leukocytes may be elevated or normal
- Platelet count is often high as a marker of inflammation/stress
- ESR is often significantly elevated
Patient presents with pulmonary symptoms, Hx of IV drug abuse with track marks, and cavitary lung lesions on imaging suggests what? Most likely organism?
- Septic embolism from infective endocarditis . .tricuspid
- Staph. aureus
Although pulmonary tuberculosis can cause similar symptoms and present with a cavitary lesion like Infective endocarditis causing septic embolism to lungs, How is TB different?
- typically presents with slowly progressive symptoms of malaise, anorexia, weight loss, fever, and night sweats along with pulmonary findings
- Chronic cough instead of dyspnea is usually the most common pulmonary symptom
For adults with suspected or confirmed influenza, What is the treatment?
- Those with no risk factors for complication do NOT require diagnostic testing and are generally treated symptomatically
- Those with risk factors (eg, age 65 or older, chronic medical problems, pregnancy) should receive antiviral therapy (oseltamivir), regardless of symptom duration.
- Antivirals can also be considered in those without risk factors who come to the office within 48 hours of symptom onset
As with all adults, patients with HIV should receive vaccination for influenza annually in the fall (but the the inactivated formulation rather than the live, attenuated or nasal formulations). They should also receive revaccination for tetanus and diphtheria (Td) every 10 years. A single dose of tetanus-diphtheria-acellular pertussis (Tdap) could be considered as it is recommended to address waning pertussis immunity, particularly in those who have not previously received Tdap. What additionaly vaccines should patients with HIV receive due to elevated risk?
- Hep B unless they have documented immunity
- PCV13, followed by the PPSV23 8 weeks later and again in 5 years and at age 65
- Many experts also recommend varicella vaccine for adults with HIV born after 1979 who do not have evidence of immunity, provided that their CD4+ count is > 200 *****
- the meningococcal vaccine including booster every 5 years
The safety of live-attenuated vaccines in those receiving tumor necrosis factor (TNF) antagonists (eg, adalimumab) is unknown, and these vaccines should be avoided in such patients. What are the live-attenuated vaccines?
- Polio (oral)
- Measles/mumps/rubella
- Rotavirus
- Influenza (intranasal)
- Yellow fever
- Varicella, zoster
Vaccination for yellow fever is recommended prior to travel to some countries in central Africa, many of which require evidence of vaccination for entry. What are the contraindications to this live-attenuated vaccine?
- Allergy to vaccine components (eg, eggs)
- AIDS (CD4 < 200), certain immunodeficiencies (including those associated with thymus disorder), recent stem cell transplantation
- Immunosuppressive therapy (eg, TNF antagonists, high-dose systemic corticosteroids)
Individual with contraindications to yellow fever vaccine who must travel to an endemic area should be provided with what?
- a medial waivers (documented in an international certificate of vaccination)
- Counseled on mosquito-protective measures
Although bacterial and viral pathogens are the most common cause of traveler’s diarrhea, parasitic organisms such as these are responsible for most cases of PROLONGED, profuse, watery diarrhea
- Cryptosporidium parvum
- Cyclospora
- Ciardia
Pulmonary nocardiosis is the most common manifestation and may present alone or with disseminated disease (eg, skin, CNS). Symptoms arise with varying chronicity but often include fever, weight loss, malaise, dyspnea, cough, and pleurisy. Imaging typically reveals what?
- Nodular or cavitary lesions in the UPPER lobes
- May be confused with malignancy or TB
This is a sporulating (not branching, not filamentous) bacterium that can be inhaled. Symptoms progress rapidly and include fever, myalgias, dyspnea, hypoxemia, and shock
Bacillus anthracis
This should be suspected in a patient from an endemic region with a history of tick bite, febrile illness with systemic symptoms, Leukopenia and/or thrombocytopenia, and elevated aminotransferases. Rash is uncommon. What is the disease and treatment/
- Ehrlichiosis
- Doxycycline
what is the epidemiology of Human monocytic ehrlichiosis?
- Transmitted by tick vector
- Seen in southeastern and south central US
TMP-SMX is the initial drug of choice for the treatment of PCP regardless of pneumonia severity. Treatment typically lasts for 21 days. Adjunctive corticosteroids have been shown to decrease mortality in cases of severe PCP (possibly by reducing inflammation due to dying organisms). What are the indication for corticosteroid use?
- Partial pressure of oxygen (PaO2 <70 mm Hg) or
- an Alveolar-arterial (A-a) gradient >35 mm Hg on room air
- Macular (often hypopigmented) anesthetic skin lesions with raised borders
- Nodular, painful nearby nerves with loss of sensory/motor function
Leprosy (mycobacterium leprae)
Describe the epidemiology of leprosy
- Mycobacterium leprae
- Primarily developing world (eg, Asia, Africa, South America
- Respiratory droplets/nine-banded armadillo
- Low infectivity
Describe how to diagnose Leprosy?
- Full-thickness biopsy of skin lesion (active edge)
- M leprae is NOT culturable
Treatment of Leprosy
- Dapsone + rifampin
- Add clofazimine if severe (“multibacillary)
fevers, headaches, and signs of elevated intracranial pressure (vomiting, papilledema) in immunocompromised patients with HIV and a negative Brain MRI
Cryptococcal meningitis
This is an opportunistic infection seen in patients with HIV that can be detected on PCR testing of CSF. Neuroimaging usually shows patchy areas of white matter consistent with demyelination
JC virus . . . . .Progressive multifocal leukoencephalopathy
HIV screening is recommended for all patients age 15-65 regardless of risk factors. It is also recommended for pregnant women, men who have sex with men, IV drug users, patients reporting unprotected sex, and those diagnosed with another STD. What is the preferred HIV screening test?
- A 4th generation assay that detects both the HIV p24 antigen AND HIV antibodies
- Patients with positive test results should then undergo confirmatory testing with HIV-1/HIV-2 antibody differentiation immunoassay
- Plasma HIV RNA testing is recommended for ppatients with negative serologic tests and high clinical suspicion of acute HIV
Routine testing for hepatitis C virus is not recommended in the general population. Guidelines recommend screening what patients?
- patients with elevated ALT
- HIV +
- HCV (eg, history of IV drug used, receiving clotting factors before 1987 or blood transfusions before 1992, chronic hemodialysis, or born in the U.S. between 1945-1965)
- Sexual contacts of patients who are HCV + should also be screened
- Testing is also recommended for health care workers after needle stick exposure to HCV + blood and for children born to patients with HCV
What is the most likely diagnosis in a patient who recently returned from a trip to the Caribbean and now has fever, malaise, rash, lymphadenopathy, and polyarthralgias (almost always present), with LYMPHOPENIA and THROMBOCYTOPENIA on lab testing
Chikungunya fever
Epidemiology of Chikungunya fever
- Central and South America, Tropical regions of Africa, South Asia
- Vector: Aedes mosquita (same as dengue fever)
Management of Chikungunya fever?
- Supportive care (resolves in 7-10 days)
- Development of chronic arthralgias, which may require methotrexate, in approximately 30%
The symptoms of Coccidioides may be subclinical, but many patients (>50%) develop community-acquired pneumonia often accompanied by arthralgias, erythema nodosum, or erythema mulitforme. This clinical syndrome is also called what?
Valley fever
Describe the difference in lymphadenopathy between Strep pharyngitis and infectious mononucleosis?
- Strep pharyngitis: tender cervical . . unlikely to cause generalize lymphadenopathy
- IM: commonly posterior cervical but may be generalized
What post exposure prophylaxis is recommended following high-risk occupational exposure to blood or body fluids from an HIV-infected individual
- 3-drug antiretroviral therapy for 4 weeks
- therapy should be started as soon as possible, preferable in the first few hours
what organism?
- Primarily lower extremity
- Cutaneous (deeper infections rare)
- Erythematous, pruritic papule at the site of entry
- Intensely, pruritic, migrating, serpiginous, reddish-brown tracks
Cutaneous larva migrans
Epidemiology of cutaneous larva migrans
- Hookwoom larvae: Dog (Ancylostoma caninum) or cat (A braziliense)
- Humans are incidental hosts
- Barefoot contact with contaminated sand or soil
This occurs most commonly on the upper arm, thorax, or inner thighs. They are characterized by a red plaque or papule with central clearing. Some patients develop a necrotic eschar
Brown recluse spider bites
The typical cycle of the protozoal malaria consists of a cold phase (chills, shivering), then a hot phase (high-grade fevers), then a sweating stage (diaphoresis, fever resolution). Headache, malaise, myalgias, vomiting, and diarrhea are often seen. What lab results are classic?
- Anemia
- Thrombocytopenia
Describe PREVENTION of malaria?
- Antimalarial drugs: Atovaquone-proguanil, Doxycycline, Mefloquine, Chloroquine, Hydroxychloroquine
- Insecticide-treated nets
- Household insecticide residual spraying
vector for malaria
Anopheles mosquito
This is also caused by a tick-transmitted RBC parasite and has a similar presentation to malaria but is more commonly seen in the northeastern and midwestern U.S.
Babesiosis
This can present with fever and headache. Symptoms typically develop 4-7 days following a mosquito bite and classically include marked muscle and joint pains, retroorbital pain, rash and Leukopenia (diagnostically useful)
Mosquito born dengue fever
- Headache
- GI symptoms
- Salmon Rose spots
- Relative Bradycardia
Typhoid fever
A febrile patient with no obvious focus of infection given normal Chest x-ray and urinalysis and severe neutropenia
Febrile neutropenia
Neutropenia is defined as what?
-Absolute neutrophil count <1500 (severe neutropenia <500)
Patients with febrile neutropenia should be started on what as soon as possible after blood cultures are obtained?
- Empiric broad-spectrum antibiotics
- Empiric monotherapy with an anti-pseudomonal agent (eg, cefepime, meropenem, Piperacillin-tazobactam) is recommended for initial management
- Antifungal meds are recommended in high risk neutropenic patients wit hpersistent fever after 4-7 days of initial therapy in whom a source of infection is not identified
What organism?
- 90% of patients asymptomatic
- Colitis (diarrhea, bloody stool with mucus, abdominal pain)
- Liver Abscess (RUQ pain, fever): complications - rupture to pleura/peritoneum
Entamoeba histolytica
This is a protozoan found in developing countries that is transmitted primarily through the consumption of contaminated food and water. Most infections are asymptomatic, but about 10% of patients have clinical symptoms of colitis or extraintestinal (liver, pleura, brain) disease
Entamoeba histolytica
What is the most common form of extraintestinal disease in E histolytica and develops when it spreads from colonic mucosa to the liver vie the portal vein?
What is the characteristic finding on imaging?
Amebic liver abscess
-Single subcaspular cyst in the right hepatic lobe
pyogenic and amebic abscesses have similar clinical and radiographic appearances. However, what differentiated pyogenic abscesses?
- More common in patients with diabetes orunderlying hepatobiliary or pancreatic disease
- Tend to develop following episodes of infection or from surgical wounds
Echinococcus granulosis can cause a hydatid liver cyst with symptoms of RUQ pain, N/V, and hepatomegaly. How would this be different from E histolytica
- Fever is rare in absence of cyst rupture
- Diarrhea is uncommon
- Patients are asymptomatic for years (not months)
A patient with primary syphilis (chancre) recieved a dose of penicillin G last night and now has an acute febrile illness, typically within 12 hours of treatment. Symptoms include headache, myalgias, rigors, sweating, hypotension, and worsened syphilitic rash (diffuse, macular, including palms and soles) . .what is this and describe it
- Jarisch-Herxheimer reaction
- This reaction is seen primarily in patients with early syphilis treated with antibiotic medication
- The rapid destruction of spirochetes causes it
- Manifestations are usually self-limited and resolve spontaneously within 48 hours
- This reaction can also occur after the treatment of otehr spirochetes (eg, Borrelia burgdorferi) and atypical organisms (eg, Bartonella)
This can occur in patients with HIV initiated on highly active antiretroviral treatment and is marked by a paradoxical worsening of infectious symptoms due to immune system improvement
Immune reconstitution inflammatory syndrome
In this etiology of meningitis, patients develop sudden symptoms, and rapid, severe progression is the norm. Manifestations often begin with fever, headache, vomiting, and severe myalgias. Withing 12-15 hours, most patients develop nuchal rigidity, AMS, and petechial rash. Shock often follows shortly thereafter.
Meningococcal meningitis
CFS findings in Meningococcal meningitis
- Low glucose (<45)
- High protein (often > 500)
- Neutrophilic leukocytosis (>1000)
What organism/disease?
- Lab: eosinophilia (usually > 20%), the hallmark of the disease, possible elevated CK and leukocytosis
- PERIorbital edema
- myositis
- eosinophilia
Trichinellosis . . roundworm
Describe the stages of Trichinellosis?
- Intestinal stage (within 1 week of ingestion): can be asymptomatic or include abdominal pain, nausea, vomiting, diarrhea
- Muscle stage (up to 4 weeks after ingestion): Myositis, Fever, subungal splinter hemorrhages, periorbital edema, Eosinophilia (usually > 20%) with possible elevated creatinine kinase and leukocytosis
This can present with intestinal symptoms and eosinophilia, but more often has a lung phase with nonproductive cough followed by an asymptomatic intestinal phase. Can also present with the worms obstructing the small bowel or bile ducts
Ascariasis
This usually presents with fever, headache, RETRO-orbital pain, rash, and significant myalgia and arthralgias. Patients can also develop a hemorrhagic form with signficant hemorrhage in the skin or nose
Dengue fever . . . . No Eosinophilia
Bright red, firm, friable exophytic nodules in a HIV infected patient
Bacillary angiomatosis . . caused by Bartonella, a Gram-negative bacillius
Treatment of Bacillary angiomatosis
Oral erythromycin
These skin lesions usually occur on the Trunk, face, and extremities. Typically the lesions are papules that become plaques or nodules. The color changes from light brown, to pink, to dark violet
Kaposi Sarcoma
This may cause nodular and papular cutaneous lesions in the external auditory meatus in immunocompromised (HIV) patients
Pneumocystis (Extrapulmonary)
Patient presents with low-grade fever and violaceous skin lesions with scrapings showing yeast . . characteristic presentation of heaped-up verrucous or nodular lesions with a violaceous hue that may evolve into microabscesses
Blastomycosis
Patients receiving solid organ transplantation require high-dose immunosuppressive medication to prevent organ rejection. this results in systemic immunosuppression, which puts them at risk for opportunistic infections, most notably what?
- Pneumocystis pneumonia
- CMV
Patient was on prophylaxis for PCP (TMP-SMX) and CMV (valganciclovir), but both meds were discontinued 2 months ago due to leukopenia. She now presents with pulmonary symptoms (dyspnea on exertion, dry cough), GI symptoms (abdominal pain, diarrhea, hematochezia), pancytopenia, mild hepatitis, and interstitial infiltrates on chest x-ray. This combo is strongly suggestive of what?
-tissue invasive DMV disease
Describe tick removal
should be removed with tweezers as soon as they are noticed to reduce the risk of a tickborned illness
Describe the antimicrobial prophylaxis criteria for Lyme disease?
- Must meet all 5
- Attached tick is an adult or nymphal Ixodes scapularis (deer tick)
- Tick attached for 36 hours or more
- Prophylaxis started within 72 hours of tick removal
- Local Borrelia burgdorferi infection rate >20% (eg, New England area)
- No contraindications to doxycycline (eg, age < 8, pregnant, or lactating)
Primary prophylaxis in HIV patients with CD4 counts < 50
- PCP and Toxo: TMP-SMX
- Mycobacterium Avium: Azithromycin or clarythromycin
Do you need primary prophylaxis of HSV or Candida in HIV patients?
no
Primary prophylaxis of Histoplasma capsulatum?
- CD4 < 150 in Endemic area
- ITRAconazole
Progressive multifocal leukoencephalopathy is due to JC virus reactivation in Severe immunosuppression (e.g. untreated AIDS CD4 < 200). It manifests as slowly progressive confusion, paresis, ataxia, seizure. How do you diagnose?
- CT brain: White matter lesions with NO ENHANCEMENT/EDEMA
- Lumbar puncture: CSF PCR for Jc virus
- Brain biopsy rarely needed
