Infectious Disease

Question 1

Which abx can treat MRSA?

Answer 1

Vancomycin

Ceftaroline

Linezolid (+tedizolid)

Daptomycin

Telavancin / dalbavancin / oritavancin

Question 2

Which abx can be used for mild MRSA skin infections?

Answer 2

Bactrim

Doxy

Clindamycin

Linezolid

Question 3

Side Effects of Linezolid

Answer 3

Serotonin syndrome (do not use w/ MAOI)

Thrombocytopenia

Question 4

Side Effects of Daptomycin

Answer 4

CPK elevation (mycin hurts myosin)

does not work in lungs (surfactant deactivates)

Question 5

Main Uses of Amoxicillin (6)

Answer 5

Otitis media

Dental infection / endocarditis ppx

Lyme if just rash, joints, CN

Listeria

Enterococcal infections

UTI in pregnant women (or nitro)

Question 6

Which abx are penicillinase-resistant? What are they used for?

Answer 6

Oxacillin, cloxacillin, dicloxacillin, nafcillin

Uses

• Skin infection (cellulitis)
• Staph meningitis, endocarditis, bacteremia
• OM / septic arthritis w/ gram pos

Question 7

Can those w/ PCN allergy use cephalosporins?

Answer 7

YES - if just rash w/ PCN

NO - if anaphylaxis w/ PCN

Question 8

Side effect of cefoxitin

Answer 8

Disulfarim like reaction w/ alcohol

depletes prothrombin –> inc risk of bleeding

Question 9

Why can’t ceftriaxone be given to newborns?

Answer 9

impairs biliary metabolism (use cefotaxime instead)

Question 10

What are carbapenems used for?

Answer 10

ANAEROBES & ESBL-PROD GRAM NEG

Ertapenem - does NOT cover pseudo (others do)

Question 11

Side effect of Bactrim

Answer 11

Rash

Hemolysis if G6PD deficiency

BM suppression - folate antagonist

Renal damage

Question 12

Anaerobe Coverage

Answer 12

Above diaphragm
- clindamycin

Below diaphragm

• metro
• any beta lactam/lactamase combo
• carbapenems
• moxifloxicin (good for diverticulitis)

Question 13

Polymixin

Answer 13

Last resort for gram neg infection (because renal toxic)

Question 14

When do you need head CT before LP?

Answer 14

Papilledema

Focal neuro findings on exam

Seizures

Confusion so cannot trust physical exam

Question 15

Who needs to be given ppx in meningitis? What is it?

Answer 15

Close contacts - major respiratory fluid contact (kissing, in same house, sharing cigs or utensils)

NOT school or work contacts

Healthcare - only if intubate, suction or contact respiratory secretions in some way

USE RIFAMPIN, CIPRO, CEFTRIAXONE

Question 16

What is Yersinia diarrhea associated with?

Answer 16

IRON - has high affinity for iron so seen in hemochromatosis patients, ppl w/ blood transfusion

**People with hemochromatosis also susceptible to vibrio cholera and listeria

Question 17

What does Hep B e-antigen tell you?

Answer 17

• correlates w/ the amount of active viral replication
• only present w/ high amount go DNA polymerase activity
• means person w/ highest e antigen is most likely to benefit from anti-viral therapy

Question 18

How do you treat Hep C genotype 1?

Answer 18

ledipasvir + sofosbuvir

Question 19

Side effects of interferon

Answer 19

arthralgia

myalgia

anemia

depression

Question 20

Cervicitis

Answer 20

• cervical discharge
• strawberry cervix

TX = ceftriazone + azithromycin

Question 21

What is the most sensitive test for syphilis in CSF?

Answer 21

FTA (fluorescent treponemal antibody)

If FTA is positive they have neurosyphilis

If VLDR and RPR from CSF are negative they may still have neurosyphilis

Question 22

Causes of False Pos VLDR/RPR in Serum

Answer 22

Infection

Older age

Injection drug use

AIDS

Malaria

Anti-phospholipid syndrome

Endocarditis

Question 23

Tx duration for proctitis

Answer 23

2-6 wks (usually chronic infection)

v. only 1 wk for cystitis

Question 24

Which 2 bacteria are associated w/ colon pathology?

Answer 24

Strep bovis

Clostridium septicum

Get colonoscopy if ID these in blood cx

Question 25

When is surgery required in endocarditis?

Answer 25

CHF w/ acute valve rupture Fungal endocarditis - replace valve If associated w/ existing prosthetic valve Abscess AV block Recurrent emboli despite abx

Question 26

Culture-Neg Endocarditis

Answer 26

Think bartonella or coxiella HACEK (H aphrophilus, H parainfluenza, actinobacillus, cardiobacterium, eikenella, kingella)

Question 27

What do you do if someone has asymptomatic tick bite?

Answer 27

Sngl dose doxy if ... - confirmed Ixodes scapularis - Engorged - attached > 24 to 48 hrs - endemic area

Question 28

First Line HIV Tx

Answer 28

2 NRTIs + Integrase Inhibitor NRTIs = tenofovir, zidovudine, lamivudine, abacavir, emtricitabine Integrase inhibitors all end in -gravir

Question 29

What is the adverse effect associated with abacavir?

Answer 29

If HLA B5701 then hypersensitivity reaction (SJS-like)

Question 30

HIV Tx in Pregnanct

Answer 30

Treat immediately - do not wait for genotype Use at least 3 drug combo during pregnancy Zidovudine during delivery, give to baby 6 wks after birth C-section if viral load > 1000

Question 31

What HIV drug are used for PrEP?

Answer 31

emtricitabine - tenofovir Cont indefinitely or 1 mo after last exposure Careful of reactivation of Hep B once stopping tenofovir

Question 32

Which disseminated fungal infection is not treated w/ amphotercin?

Answer 32

Aspergillus - use voriconazole, isavuconazole or caspofungin instead DO FOR ... Coccidio, histoplasmosis (followed by itraconazole), mucormycosis, blasto

Question 33

How do you treat severe malaria?

Answer 33

artemisinin CNS dysfunction, hypotension, shock, parasitemia > 5%, renal injury

Question 34

Malaria PPX

Answer 34

Mefloquine or atovaquone/proguanil

Question 35

Chikungunya Zika Dengue

Answer 35

All transmitted by Aedes mosquito Chik = intense joint pain Zika = microcephaly if pregnant, GBS Dengue = break bone fever, also low WBCs, high LFTs

Question 36

Ebola

Answer 36

NOT transmitted by mosquito, direct contact w/ body fluids Viral syndrome w/ high volume diarrhea Low WBC, low platelet, high LFTs Hypovolemic shock Encephalitis

Question 37

How do you treat babesiosis?

Answer 37

Azithromycin + atovaquone

Question 38

Leptospirosis

Answer 38

Ingestion of foods infected w/ animal URINE Oligouria, liver problems, muscle pain (high CK) ELISA Tx - PCN, amoxicillin, ceftriaxone or doxy

Question 39

Treatment of Leishmania

Answer 39

SANDFLIES Stibogluconate (steak)

Question 40

Bacillary Angiomatosis

Answer 40

Caused by bartonella HIV-AID w/ CD4 < 100 Purple/red vascular papules that bleed easily + Constitutional sx + Liver/bone/CNS Tx = anti-retrovirals, doxy and erythromycin