Unit 5 Flashcards
HIV patients with the following should be offered primary pneumocystis prophylaxis
● CD4 count < 200 cells/mcL
● CD4 lymphocyte percentage < 14%
● Weight loss
● Oral candidiasis
Patients with a history of Pneumocystis should receive secondary prophylaxis until …
● viral load is undetectable AND
● They have maintained a CD4 count > of 200 cells/mcL while receiving ART for > 3 mo.
Pneumocystis prophylaxis meds
-Trimethoprim-sulfamethoxazole 1 double-strength tablet 3 times a week -up to- 1 tab daily
● After treatment of an infection with Pneumocystis jiroveci prophylaxis should be maintained
until CD4 count is > 200 for 3 months.
● If patient intolerant to Bactrim treat with Dapsone or Atovaquone.
Dapsone 50-100 mg daily or 100 mg 2to3 times per week (if Bactrim not tolerated)
Atovaquone 1500 mg daily with a meal
Pentamidine (IV or aerosolized)
Preexposure ART Prophylaxis (PrEP) Regimen
-Used for those at high risk for contracting HIV
-● emtricitabine/TDF (Truvada) - reduces the risk of sexual transmission of HIV among uninfected
individuals at high risk for infection, and in men who have sex with men.
● Tenofovir - reduces HIV infections among injection drug users
Post-exposure prophylaxis (PEP): Goal, when to give
-Goal of therapy is to reduce/prevent local viral replication prior to dissemination to abort infection
● Treatment should be started as soon as possible, success declines with increased length of time from
HIV exposure. Treatment not recommended to be offered > 72 hours after exposure
● Treatment should be offered with prevention counseling; focusing on how to prevent future exposures
Post-exposure prophylaxis (PEP): Regimen
Preferred regimen: tenofovir with emtricitabine (Truvada) with raltegravir
Who should get ART therapy
All HIV-infected patients should be considered for ART regardless of CD4 count. The benefit of
ART is well established in preventing progression to AIDS and associated comorbidities.
What is symptomatic HIV
Symptomatic HIV: the presence of any of the following: thrush, vaginal candidiasis, herpes zoster,
peripheral neuropathy, bacillary angiomatosis, cervical dysplasia in situ, constitutional symptoms
such as fever or diarrhea for more than 1 month, ITP, PID or listeriosis.
Goals of ART therapy
-CD4 cell counts and HIV viral load should be repeated 1-2 months after initiation or change
of ART regimen and every 3-4 months thereafter in clinically stable patients.
■ With integrase regimens 80% of patients will have undetectable HIV viral load at 1
month.
■ All patients should have undetectable HIV viral load by 3 months
■ If not, the usual problem is compliance.
Opportunistic Infections of HIV
●Pneumocystis jiroveci pneumonia*** most common
● Toxoplasma gondii encephalitis (Toxoplasmosis)
● Mycobacterium tuberculosis disease (TB)
● Disseminated MAC disease
● Non-Hodgkin lymphoma
● Cryptococcal meningitis
● Cytomegalovirus retinitis (sight threatening)
● Esophageal candidiasis
● Vaginal candidiasis
● Herpes simplex infection
● Herpes zoster
● Kaposi sarcoma
● Aspergillosis
What causes increased risk of AIDS-related
complications
Drug holidays or structured treatment interruptions have be shown to increase risk of AIDS-related
complications - the interruptions are NOT recommended
Only stop ART for toxicity
when a diagnosis of AIDS
Look up answer to this
What test is necessary for osteomyelitis diagnosis
bone biopsy
most common pathogen identified in causing Community acquired pneumonia
Strep pneumoniae
Most common cause of pneumonia is young adults and adolescents
Mycoplasma pneumoniae
Pneumocystis, candida, herpes.
know treatments
Influenza vaccine is given in which months
September and October
Most common fungal infection for HIV patients
Candida
look at pics
for herpes zoster and skin cancer
What if patient is not at goal after months of ART therapy
-ASK ABOUT MED COMPLIANCE
-Resistance testing is recommended for patient receiving ART and have suboptimal viral
suppression.
● Resistance testing is complex, many clinicians require expert interpretation of the results
● Resistance testing should NOT replace a carefully documented history of what medications the
patient has taken in the past and for how long.
● After testing and with knowledge of patient history a second-line ART regimen is constructed with 3
medications (from 2 different classes) to which the virus is not resistant.
● With the availability of new classes and new generations medications, a combination of ART can
successfully treat virtually all patients - no matter how much resistance is present.
Normal Spinal fluid analysis: cells
0–5 lymphocytes
Normal Spinal fluid analysis: glucose
45–85
Normal Spinal fluid analysis: protein
15–45
Normal Spinal fluid analysis: opening pressure
70–180 mm H 2 O
Purulent meningitis Spinal fluid analysis (numbers)
200–20,000 polymorphonuclear neutrophils
Low (< 45) glucose
High (> 50) protein
opening pressure Markedly elevated (>180)
Clinical manifestations of meningitis
fever (high > 38C), nuchal rigidity, change in mental status, Headache, N/V, photophobia, seizures coma, lethargy, Rash: petechial, purpura fulminans, myalgia, unilateral CN abnormality, Papilledema, dilated on responsive pupils, posturing decorticate/decerebrate,
Kernig & Brudzinkski- seen in later
Meningitis workup
-Stat labs, history/phyiscal
-CT BEFORE LP if pt presents with SAH, new focal neuro deficit, papilledema, seizures within one week,
AMS, CNS (tumor, stroke), age > 60, immunodeficient
-Lumbar puncture
-Empiric therapy
Empiric therapy for meningitis
- Dexamethasone 10 mg iv q 6hr x 4 days
- Selected third-generation cephalosporins (ie, cefotaxime 2gm iv q 4-6 hr and ceftriaxone
2g iv q 12) are the beta-lactams of choice in the empiric treatment of meningitis, vancomycin 15-20 mg/kg iv q 8-12 hrs should be added to cefotaxime or ceftriaxone as empiric treatment until culture and susceptibility results are available due to penicillin-resistant pneumococci - Adult > 50 add ampicillin 2 gm iv q 4 hr to cover listeria
Bacterial Endocarditis Essentials of Dx
i. Fever.
ii. Pre-existing organic heart lesion.
iii. Evidence of vegetation on echocardiography.
iv. New or changing heart murmur.
v. Evidence of systemic emboli
What is bacterial endocarditis, what is the virulent type?
-Bacterial infxn of the valvular or endocardial surface of the heart.
-Clinical presentation depends on the infecting organism and the valve/valves
infected.
-S. aureus : Virulent organism
How does a patient with endocarditis caused by more virulent organisms present
- Acute febrile illness.
- Complicated by early embolization, acute valvular regurgitation, and
myocardial abscess formation.
Less virulent strains of endocarditis
Viridian strains of streptococci, enterococci, other bacteria, yeasts, and fungi tend
to cause a more subacute presentation
Valvular Dz with endocarditis, what is it, what does it do
- Present 50% of the times.
- Alters blood flow and produces jet effects that disrupts the endothelial surface, providing a nidus (Nest. Site of origin for disease or bacteria. A place where bacteria multiplies) for attachment and infection of microorganisms to enter the bloodstream.
Predisposing Valvular Abnormalities
- Rheumatic involvement of any valve, bicuspid aortic valves, calcific or
sclerotic aortic valves, hypertrophic subaortic stenosis, mitral valve
prolapse. - Rheumatic Dz is no longer the major predisposing factor in developing
countries. - Regurgitation lesions are more susceptible than stenotic ones.
The initiating event in Native Valve Endocarditis
- colonization of the valve by bacteria that gain access to the bloodstream.
1. Transient bacteremia is common during dental, upper respiratory, urologic, and lower GI diagnostic and surgical procedures.
2. Less common in upper GI and gynecologic procedures.
Intravascular Devices role in bacterial endocarditis
-increasingly implicated as a portal of access of
microorganisms into the bloodstream.
-A large proportion of cases of S. aureus endocarditis are attributed to health-care associated bacteremia.
Native Valve Endocarditis leading causative organism
- S. aureus
- > 60% of injection drug user cases.
- 80-90% of cases: Tricuspid Valve is infected
Prosthetic Valve Endocarditis leading causative organism, early and late
- Early infxns: Occurring w/in 2 months after valve implantation; Commonly caused by staphylococci: Coagulase-Positive Organisms, Coagulase-Negative Organisms
- Late Prosthetic Valve Endocarditis: Streptococci commonly identified
signs and symptoms of bacterial endocarditis
Fever, Duration: Typically a few days to weeks, Changing regurgitant murmur (Significantly diagnostic), Cough, Dyspnea, Arthralgias/Arthritis, Diarrhea, Abdominal, Back, Flank Pain, Characteristic Peripheral Lesions, Strokes and major embolic events are present in about 25% of patients (Tend to occur before or w/in the first week of antimicrobial tx), Hematuria and Proteinuria may result from emboli or immunologically mediated glomerulonephritis causes Kidney Dysfxn.
Peripheral lesions associated with bacterial endocarditis
- Petechiae: On the palate or conjunctiva or beneath the fingernails.
- Subungual (Splinter) Hemorrhages.
- Osler Nodes: Painful, Violaceous raised lesions of the Fingers, Toes, or Feet).
- Janeway Lesions: Painful erythematous lesions of the palms or soles.
- Roth Spots: Exudative lesion in the retina. Occur in about 25% of patients.
Antibiotic Management of Bacterial Endocarditis
i. Empiric regimens while culture results are pending. Should include agents active against staphylococci, streptococci, etc enterococci.
ii. Vancomycin 1gm q12hrs IV + Ceftriaxone 2gm q24hrs provides appropriate
coverage pending definitive diagnosis.
iii. Infectious Dz Consultation: Strongly preferred/recommended.
Most common agent of CAP in AIDS/immunocompromised pts
Pneumocystitis jirovecii
Antibiotic therapy for a patient diagnosed with pneumonia caused by S. pneumoniae if no prior use of abx
- azithromycin or clarithromycin + macrolide
Antibiotic therapy for a patient diagnosed with pneumonia caused by S. pneumoniae if at risk for drug resistance, >65 years old, comorbidities, immunosuppresion
-A fluoroquinolone (levo, moxi, or gemi floxicin)
OR you can treat with:
-Combo of macrolide PLUS beta-lactam (amox or amox/clav)
- Give for a minimum of 5 days and recommended until patient is afebrile for 48-72hours
Most common sites for nosocomial infections
- Urinary tract infections caused by foley catheters are the most common
- Others are blood stream infections from central lines, surgical wounds, abscesses
- Pneumonia in intubated patients
- Those most at risk are those critically ill, hospitalized for long durations and those who have received multiple abx courses
Malarial prophylaxis when traveling to country WITHOUT drug resistant parasites
-Bug repellant, insecticides, and bed nets are the
most effective prevention
- Chemoprophylaxis is recommended for all travelers from non-endemic to endemic areas
- Chloroquine
Malarial prophylaxis when traveling to country WITH drug resistant parasites
-Bug repellant, insecticides, and bed nets are the
most effective prevention
- Mefloquine or Malarone or doxycycline are all used in resistant areas
Management of VRE
- If rectal or stool then no tx recommended
- If resistant to Vanco, often resistant to many other abx (80% will be resistant to ampicillin also)
- Potential tx agents are: Linezolid or Daptomycin
- Also mentions Quinupristin- dalfopristin (synercid) but this is only effective on rare strains and it causes myalgias, arthralgias, and venous irritation so rarely used
Pyelonephritis causative agents in hospital
E. coli., Klebsiella, enterobacter or
pseudomonas
Pyelonephritis causative agents outpatient
E. coli, K. pneumoniae, Proteus species, or s.
Saprophyticus
Antibiotic management of pyelonephritis in hospital
These will be tx w/ceftriaxone 1gm q24h OR cipro 400mg q12h OR levofloxacin 500mg q24 *all IV
If empiric tx is started while waiting on abx then should be ampicillin & gent OR cipro, levofloxacin, or bactrim**
Antibiotic management of pyelonephritis outpatient
These are tx with fluoroquinolones for 7 days (*preferred) or Bactrim for 7-14 days
Workup to Dx of osteomyelitis
ESR (high), CRP, blood cx, bone cx, bone biopsy (required for diagnosis), PCR analysis of specimens, xray, MRI best, SPECT
signs and symptoms of osteomyelitis
fever/chills, painful/tender bone (sometimes neuropathic pain if pt has vascular insufficiency)
Inpatient and outpatient treatment for osteomyelitis
- In hospitalized patients tx is IV nafcillin 2gm q4h or cefazolin 2gm q8h for MSSA
- If MRSA susp. Tx w/ vanc or dapto instead
- In outpatient 6-8 weeks of fluoroquinolones, can add rifampin if s. Aureus is the cause
Challenges to treating osteomyelitis
- Chronic osteomyelitis has high tx failure rates due to poor vascular supply, nondistensible bone tissue, and limited penetration of bone tissue.
- Inadequate treatment of bone infections results in chronicity of infection, and this possibility is increased by delaying diagnosis and treatment. Extension to adjacent bone or joints may complicate acute osteomyelitis
- Hyperbaric sometimes needed chronic, or ID specialist if multiple tx failures
- Most patients will require I & D and LONG abx tx course
Causes and Antibiotic management of intra-abdominal infections
● Intra-Abdominal sepsis (postoperative, peritonitis, cholecystitis ect): likely caused by
gram neg, anaerobic, streptococci, or clostridia.
● Tx: Piperacillin-Tazobactam 4.5Gm IV q6h OR ertapenem 1 Gm IV daily
Characteristics of fever of unknown origin
- illness at least 3 weeks
- Fever over 38.3C on several occasions,
- No Dx after 3 hospital visits or 3 days inpatient
Causes of fever of unknown origin
Infection (most common), neoplasm, autoimmune disorders, miscellaneous, undiagnosed
Management of fever of unknown origin
-Thorough history, Labs + blood cultures, CXR, CT abd/pelvis, LP, HIV testing, any other testing such as biopsies, MRIs, etc. don’t just randomly give Abx or
steroids because it may delay Dx/Tx.
● Refer if immunocompromised, rapidly declining, weight loss, recent organ transplant
Causes of a fever in a post-op patient on day one
medications given perioperatively, surgical trauma, infections that were present before surgery, necrotizing fasciitis (due to group A strep), malignant hyperthermia (from anesthesia), rapidly developing chemical pneumonitis (from aspiration of stomach contents)
Management of a fever in a post-op patient on day one
Treat the cause
Endemic regions for Histoplasma capsulatum fungus
● Central and eastern US (Ohio River and Mississippi River beds), eastern canada, Mexico, Central and
South America, Africa, and Southeast Asia
● Isolated from soil in river valleys contaminated with bird and bat droppings
Fungal infections that clinically manifests in the central nervous system
● Disseminated coccidioidomycosis can cause fungal meningitis, brain abscess, and granuloma formation.
● *Cryptococcus, Aspergillus and Candida can cause fungal cerebritis.
● *Aspergillus can cause meningeal vasculitis with vessel thrombosis and localized brain infarction
Which causative agent of malaria is most virulent and fatal
Plasmodium falciparum - responsible for nearly all severe disease
Which agent is transmitted via cat feces
Toxoplasmosis - definitive host of T gondii are cats.
Anthrax inoculation: injectional
May have similar skin lesions present with IV drug users, which may progress rapidly with systemic dissemination; NOT associated with eschar formation
Anthrax inoculation: Cutaneous
-Occurs within 2 weeks post-exposure to spores; no latency period; self-limiting in most cases, but hematogenous spread with sepsis or meningitis may occur
- Initial lesion: erythematous papule, often on exposed skin that vesiculates, ulcerates, and undergoes necrosis, progressing to purple-black painless eschar ;
pain indicates secondary staphylococcal or streptococcal infection
- Surrounding area: edematous, vesicular, not purulent
- Signs/Symptoms: regional adenopathy, fever, malaise, headache, N/V
Anthrax inoculation: inhalation
- occurs in 2 stages ~10 days post-exposure, may have latent onset 6 weeks
- Signs/Symptoms:
Initial stage - nonspecific viral symptoms like fever, malaise, headache, dyspnea, cough, congestion (nose, throat, larynx), anterior chest pain (mediastinitis);
Fulminant stage - within hours to few days; sepsis signs,hemorrhagic meningitis (delirium, obtundation, meningeal irritation)
Anthrax inoculation: Gastrointestinal
- occurs within 2-5 days post-ingestion of contaminated meat
- Initial lesion: ulcerative, produces blood-tinged or coffee-ground emesis and blood-tinged or melenic stool; bowel perforation can occur
- Signs/Symptoms: fever, diffuse abdominal pain, rebound abdominal tenderness, vomiting, constipation, diarrhea
- Oropharyngeal form: local lymphadenopathy, cervical edema, dysphagia, upper respiratory tract obstruction
Which inoculation route of Anthrax has highest mortality rate
● Inhalational anthrax is the most lethal form (>90%), higher mortality with meningeal
infection
● Fatality rates: Cutaneous <1%, GI 25-60%, Injectional 34%
Clinical manifestations of Group A beta strep infection
-Gram positive
-STREP PHARYNGITIS, SCARLET FEVER, IMPETIGO,
ERYSIPELAS, ARTHRITIS, PNEUMONIA, EMPYEMA, ENDOCARDITIS, NECROTIZING FASCIITIS, STREPTOCOCCAL TOXIC SHOCK SYNDROME
Empiric management of a patient with abdominal pain and free air on abdominal x-ray
○ Broad spectrum antibiotics to cover both gram negative aerobic and anaerobic bacteria:
● Mild-moderate disease: piperacillin-tazobactam 3.375g IV Q6H or 4.5g IV Q8H OR ticarcillin-clavulanate 3.1g IV Q6H. Alternative agents: ciprofloxacin 400mg IV Q12H or levofloxacin 750mg IV Q24H plus metronidazole 1g IV Q12H
● Severe life-threatening disease: imipenem 500mg IV Q6H or meropenem 1g IV Q8H.
Alternative agents: ampicillin plus metronidazole plus ciprofloxacin
Lab tests used to diagnose herpes simplex virus: Direct Fluorescent antibody slide tests
offer rapid, sensitive diagnosis
Lab tests used to diagnose herpes simplex virus: Viral Culture
helpful; most definitive method for diagnosis; results in 1-2 days; lesions should be sampled during vesicular or early ulcerative stage; cervical samples taken from endocervix
Lab tests used to diagnose herpes simplex virus: Pap Smear
will detect HSV-infected cells in cervical tissue from women without symptoms
Lab tests used to diagnose herpes simplex virus: Serologic Tests
IgG & IgM serum antibodies to HSV occur in 50-90% of adults; presence of IgM or four-fold or greater rise in IgG titers indicate recent infection
Lab tests used to diagnose herpes simplex virus: Western Blot/ELISA
specific HSV-2 serology can determine who is infected and potentially infectious; useful in couples in which only 1 partner reports genital herpes history
Lab tests used to diagnose herpes simplex virus: Tzanck Smear
readily available test shows multinucleated giant cells, but not highly sensitive
Lab tests used to diagnose herpes simplex virus: PCR
Test for herpes
Cause of herpes zoster
varicella-zoster virus
signs and symptoms of herpes zoster
Pain along course of nerve with grouped vesicular lesion; usually unilateral on face or trunk; regional lymphadenopathy; direct fluorescent antibody test will be positive
Prevention of herpes zoster
live Zostavax vaccine
Treatment in immunocompetent host with herpes zoster
oral acyclovir for 7 days, systemic corticosteroids
to shorten s/s, opioids, TCAs, gabapentin
Treatment in immunocompromised host with herpes zoster
acyclovir until lesions have completely healed
(2 weeks); do NOT use corticosteroids
Questions to include in a comprehensive travel history
Geography (rural vs urban, specific country visited), time of year, animal or insect
contact, unprotected sexual intercourse, ingestion of untreated water or raw foods,
historical or pre-travel immunizations, adherence to malaria ppx
Stage 1 of pertussis
Catarrhal: 1-2 week prodrome similar to common cold, followed by increased mucus production and excessive lacrimation with conjunctival infection
Stage 2 of pertussis
Paroxysmal: intense paroxysmal cough ending with gasps and inspiratory whoop. Anoxia, cyanosis, apnea, posttussive gagging/vomiting
Stage 3 of pertussis
Convalescent: lasts over 2 months as cough slowly decreases in severity
Rabies post exposure prophylaxis-when is it indicated
The decision to treat should be based on the circumstances of the bite, including the extent and
location of the wound, the biting animal, the history of prior vaccination, and the local epidemiology of rabies.
● Any contact or suspect contact with a bat, skunk, or racoon is usually deemed sufficient indication to warrant prophylaxis
● Postexposure treatment including both immune globulin and vaccination should be administered as promptly as possible when indicated
-Consultation with state and local health departments is recommended
What is Giardiasis
- A protozoan parasite capable of causing sporadic or epidemic diarrheal illness.
- Giardiasis is an important cause of waterborne and foodborne disease, daycare center outbreaks, and illness in international travelers.
Transmission and incubation of Giardiasis
- Transmission of infectious Giardia cysts to humans may occur via three routes:waterborne, foodborne , or fecal-oral transmission
- incubation period of 7 to 14 days
Signs and symptoms of Giardiasis
Diarrhea, Malaise, Foul-smelling and fatty stools (steatorrhea), Abdominal cramps and bloating, Flatulence, Nausea, Weight loss, Vomiting, Fever, Constipation, Urticaria
Tests for Giardiasis
Test the SHIT : direct immunofluorescent assays (DFA) ,
immunochromatographic assays, and enzyme-linked immunosorbent assays (ELISAs) DFA and ELISA now routinely used are 85-98% sensitive and 90-100% specific, Nucleic acid amplification assays(NAAT ).
● Serum albumin, VIt B12 and stool fat to exclude malabsorption
management of Giardiasis
● Tinidazole 2 gm single dose > 3 yrs old side effect of metallic taste, nausea , headache,
avoid booze
● Metronidazole 250 mg po TID x 5-7 days ( not during pregnancy)
● If pregnant , for 1st trimester: paromomycin ( less systemic) 25-35 mg/kg/ay in 3 doses
for 5-10 days
● typically resolve within five to seven days