Infectious Disease Flashcards
(42 cards)
Treatment of latent TB (+duration)
- HIV positive
- HIV negative
- INH x 9 months (add pyridoxine)
2. INH x 6 months or Rifampin x 4 months
Treatment for active TB (with duration)
1st –> RIPE (rifampin, isoniazid, pyrazinamide, ethambutol) x 8 weeks
–> Then isoniazid + rifampin x 4-7 months
What 3 criteria determine that TB patient is no longer infectious?
- Adequate tx for >2wks
- improved sx
- 3 consecutive negative sputum smears
What should you monitor if treating with pyrazinamide or ethambutol?
- uric acid levels
- visual acuity
- color vision
Name 3 rapidgly growing myobacterium causing localized skin and soft tissue infections
Myobacterium abscessus/fortuitum/chelonae
occur after trauma, surgery, cosmetic procedures, pedicures, tattooing, body piercing
Source – contaminated, nonsterile water
Name two groups of people that may have pulmonary MAC infection? Where is infection usually localized?Name one group that may have disseminated MAC infection?
Pulm:
- middle aged - older adult male smoker with underlying lung disease –> CXR looks like pt with TB
- elderly, thin, white female, may have suggestion of connective tissue defect (scoliosis, pectus excavtum, MVP) with CXR showing RML or left lingular lobe infection
Dissem:
- HIV with CD4<50 not on MAC ppx
Most common form of meningitis in AIDS patient? How to treat it?
cryptococal meningitis
CD4<100
high opening CSF pressure
dx - cryptococcal Ag in CSF, or +CSF culture
Tx -
induction with amphotericin B + flucytosine
maintenance - fluconazole (for pts with AIDS until CD4>100 x over 3 months)
HIV post exposure prophylaxis treatment regimen? When to test for HIV ?
- Start <72hr after exposure
- 3 drug regimen: tenofovir + emtricitabine + either raltegravir or dolutegravir
- HIV testing of the exposed person should be conducted at baseline, then 6 weeks, 12 weeks, and 5 months after exposure
Whats the HIV drug regimen for PrEP? What to test for before starting PrEP? What to monitor during PrEP?
- tenofovir + emtricitabine
- HIV, HBV, kidney function, pregnancy
- monitor Q3months - HIV, STIs, pregnancy, kidney function
Zika screening
- asx preg
- sx, non-preg
- Asymptomatic, pregnant - may have been exposed, test IgM antibody
- Symptomatic, non pregnant – NAAT (nucleic acid amplification testing) for dengue and Zika on serum, within 7 days of Sx onset
- If >7days since Sx OR NAAT (-) then do IgM antibody testing
gram-negative coccobacillus with a “safety-pin” appearance (bipolar staining pattern)
- name organism
- clinical presentation
- treatment
- Yersenia Pestis (potentially lethal, ease of dissemination)
- Pulmonary involvement via - primary (via close contact) or via hematogenous spread to lungs from buo or other source
- Tx streptomycin or gentamicin.
Can also cause fever/diarrhea/RLQ pain = mimic appendicitis!
Which two types of malaria are the most severe/lethal? Where are they endemic?
P. falciparum – Africa
Plasmodium knowlesi – South and Southeast Asia
What is the most common cause of viral meningitis? treatment?
Enterovirus (may - november) – supportive treatment
HSV2 - year round
others…
HSV2 - supportive
VZV - IV acyclovir
West Nile Virus or St. Louis encephalitis - supportive
What is Neuroborreliosis? how do you treat it?
- Facial nerve palsy (CN VII) + headache +/- nuchal rigidity (meningitis)
- Neuroborreliosis occurs in 10% to 15% of patients with Lyme disease
- Treatment IV ceftriaxone, cefotaxime, or penicillin (meningitis) – can defer Abx until LP obtained
- Treatment PO doxy 14-28days if facial palsy (uni or bilateral)
Explain Syphillis Testing
- “reverse screening”- regular testing
Treponemal test = enzyme immunoassay
NONtreponemal test = Rapid plasma regain or Venereal Disease Research Laboratory
“reverse screening”
- EIA (+) and RPR/VDRL (-) = previously treated for syphillis***
- EIA (+) and RPR/VDRL (+) = new syphillis infection
***in this case should repeat treponemal test to confirm EIA (flourescent treponemal antibody test)
RPR and VDRL pearls:
- often negative in primary infection
- positive with high titers in secondary syphillis
- positive with low titers in tertiary syphillis
- **confirm positive EIA with FTA-ABS (fluorescent treponemal antibody absorptiontest) or TPPA (treponema pallidum particle agglutination assay)
explain 3 step screening test for HIV
1st – EIA for HIV antibody (HIV-1 and HIV-2) and HIV p14 antigen… if positive…
2nd – immunoassay to differentiate HIV-1 from HIV-2
»_space; if either (+) - confirms HIV diagnosis
»_space; if (-)/inconclusive - get NAAT
3rd – NAAT (+) = acute HIV, if NAAT (-) initial test was false positive
fresh water/pool swimming, then diarrhea, what caused it? Treatment?
Cryptosporidium - parasitic protozoan is tolerant to chlorine and can persist for days in a chlorinated pool (HIV at high risk)
Tx - supportive. If very symptomatic - Nitazoxanide
Severe vs Fulminant C.diff? difference in treatment?
SEVERE = low albumin (<3) + WBC>15 or abdominal tenderness // Cr>1.5 + WBC>15
— Tx PO Vanc x 10 days
FULMINANT = severe + complications (ie. ileus, hypoTN, shock, toxic megacolon)
— Tx PO vanc + IV metronidazole q8h
At what MIC level should you not use Vancomycin for MRSA infection and switch to Dapto? What type of of MRSA infection can you NOT use Dapto for?
- MIC > 2 (MIC 4-8 = intermediate sucept. but high treatment failure for MRSA)
- pneumonia b/c daptomycin is inactivated by surfactant
When should rifampin be added to vancomycin?
prosthetic joint infection (osteo) with bacteremia - staph auerus - when hardware cannot be removed
Nodular infection (cellulitis) of extremities (nodular) with exposure to fish tank/marine?
- name organism
- treatment
- myobacterium marinum
- MILD – clarithromycin OR Doxy or Bactrim
SEVERE – clarithomycin + ethambutol OR rifampin
Diarrheal illness after adopting pet reptile (snakes, turtles, iguanas, frogs, toads)
- organism
- clinical symptoms
- Nontyphoidal Salmonella
- Transferred by animal feces to people OR via contaminated food (poultry, beef, eggs, milk)
2, Clinically - crampy abdominal pain, fever, nonbloody diarrhea, and vomiting.
Treatment for PJP pneumonia? When would you add glucocorticoids?
3 weeks of
- IV or PO bactrim (based on severity)
- If sulfa allergy – IV pentamidine or IV clinda + PO primaquine
IF A-a>35mmHg or PO2 <70 = use glucocortioids within 72hr
Treatment of toxoplasmosis in immune suppressed patient or HIV with CD4<200
sulfadiazine + pyrimethamine + folic acid (if you see multiple ring enhancing lesions on brain imaging). Biopsy if fail to respond within 2 weeks of empiric therapy.
