Infectious Disease

Question 1

Lyme Disease
Path:
Pt:
Dx:
Tx:

Answer 1

Path: Borrelia burgdorferi, north-central and northeastern US, blacklegged tick main vector

Pt: Patient with a history of being in the woods hiking or camping complaining of:
Stage I: erythema migrans (bull’s eye lesion with central clearing), viral like syndrome
Stage II: myocarditis, bilateral Bell palsy
Stage III: chronic arthritis, chronic encephalopathy

Dx: ELISA followed by Western blot if ELISA is positive or equivocal. During times of EM, serologic testing often negative

Tx: doxycycline
children- amoxicillin or doxycycline (teeth)
pregnant- amoxicillin

Question 2

MRSA Abx coverage

Answer 2

Oral:
-SMX-TMP
-minocycline
-doxycycline
-clindamycin
-linezolid
IV:
-vancomycin
-daptomycin
-ceftaroline (also vanc resistance)

Question 3

Anaerobic abx coverage

Answer 3

-metronidazole
-augmentin
-clindamycin
-pip/tazo
Carbapenems: -> imipenem/cilastatin, meropenem, doripenem ertapenem

Question 4

Atypicals: Path and abx coverage

Answer 4

Path: mycoplasma, chlamydia, legionella

Doxycycline
Azithromycin
Levofloxacin
Ciprofloxacin

Question 5

Pseudomonas abx coverage

Answer 5

FQ-> cipro, levo, ofloxacin

AG-> tobi, amikacin, gent, streptomycin

Carbapenems-> imipenem/cilastatin, meropenem, doripenem
Aztreonam

BL->Pip/tazo, Cefepime, ceftazidime

Question 6

HIV with CD4 count 200 - 500

At risk infections and tx

Answer 6

TB
Tx:
1st line: Isoniazid if latent
2nd line: Rifampin

Kaposi Sarcoma
Thrush
Lymphoma
Zoster

Question 7

HIV with CD4 count = 200

At risk infections and tx

Answer 7

Pneumocystis (PCP)
Tx:
1st line: SMZ-TMP
2nd line: Dapson, Atovaquone, Pentamidine (aerosolized)

Question 8

HIV with CD4 count = 150

At risk infections and tx

Answer 8

Histoplasmosis
Tx:
1st line: Itraconazole
2nd line: Amphotericin B

Question 9

HIV with CD4 count = 100

At risk infections and tx

Answer 9

Toxoplasmosis
Tx:
1st line: TMP-SMX
2nd line: Dapsone + Pyrimethamine + Folic Acid

Cryptococcus
Tx:
1st line: fluconazole
2nd line: amphotericin B

Question 10

HIV with CD4 count = 50

At risk infections and tx

Answer 10

MAC
Tx:
1st line:
Azithromycin
Clarithromycin
2nd line:
Rifabutin-> must obtain CXR prior to use to r/o active TB

CMV retinitis
Tx:
1st line: Valganciclovir 450mg/day
2nd line: Ganciclovir + Foscarnet

Question 11

HIV

dx:

Answer 11

ELISA (screening test) 
If reactive the test is confirmed by Western Blot 
Usually becomes reactive within 3-6m
5% seroconvert in 7 days
50% in 20 days
>95% in 90 days 

Rapid testing: blood or saliva

Western Blot: confirmatory test