Infectious DIsease

Question 1

Infective Endocarditis

Answer 1

• infection of the endocardium

- commonly affects heart valves, esp mitral valve

Question 2

Risk factors for infective endocarditis

Answer 2

• Rheumatic, Congenital or Valvular Disease
• Prosthetic heart valves
• IV drug use
• Immunosuppression

Question 3

Most common causative agent in infective endocarditis

Answer 3

S. aureus

- responsible for > 80% of acute bacterial endocarditis in pts with hx of IV drug use

Question 4

Main causative agents in infective endocarditis

Answer 4

• S. aureus
• Viridans streptoccocci
• Coagualse negative Staphylococcus
• Streptococcus bovus
• Candida and Aspergillus

Question 5

Viridans strep in infectious endocarditis

Answer 5

• most common pathogen for left-sided subacute bacterial endocarditis and following dental procedurs in native valves

Question 6

Coagulase negative streptococcus in infectious endocarditis

Answer 6

• most common infecting organism in prosthetic valves

Question 7

Streptococus bovis endocarditis

Answer 7

S. bovis endocarditis associated with co-existing GI malignancy

Question 8

Candida and Aspergillus endocarditis

Answer 8

account for most cases of fungal endocarditis

- predisposing factors are: long-term IV catheters, malignancy, AIDS, organ transplant, and IV drug use

Question 9

Pt presents w/ fever and new / change inmurmur. Likely diagnosis?

Answer 9

Endocarditis

Question 10

Complications of endocarditis

Answer 10

JR = NO FAME
Janeway lesions (flat and painless)
Roth spots in eyes
Nail-bed (splinter) hemorrhage
Osler's nodes (raised and painful)
Fever
Anemia
Murmur
Emboli to lung or brain

Question 11

Endocarditis: Hx adnd PE

Answer 11

• Constitutional sx (fever/FUO, weight loss, fatigue)
• exam reveals heart murmur (MV > AV) in non-IV drug users; right sided murmur in IV drug users (tricuspid > MV > AV)
• immune phenomena (e.g. splinter hemorrhages, Roth spots)

Question 12

Diagnosis of Endocarditis

Answer 12

• Duke’s criteria
  
  • 2 major, 1 major + 3 minor, 5 minor
• CBC with leukocytosis and left shift; incr ESR and CRP

Question 13

Best initial test for endocarditi

Answer 13

• Blood cultures
• ## TTE

Question 14

Duke’s Major Criteria for Endocarditis

Answer 14

1. At least 2 separate positive blood cx for a typical organism, persistent bacteremia w/ any organism or a single culture of Coxiella
2. Evidence of endocardial involvement (via TTE/TEE) or new murmur

Question 15

Duke’s Minor Criteria

Answer 15

1. predisposing factors
2. Fever > 38.3
3. Vascular phenomena: septic emboli, septic infarcts, mycotic aneurysm, Janeway lesions
4. Immune phenomena: GN, Osler’s nodes, Roth’s spts,
5. Microbiological evidence that doesn’t meet major criteria

Question 16

Tx of infective endocarditis

Answer 16

Best empiric treatment is vancomycin and gentamycin

- narrow abx course wherever appropriate

Question 17

Tx of Viridans Strep endocarditis

Answer 17

• Ceftriaxone for 4 weeks

Question 18

Tx of S. aureus (MSSA)

Answer 18

Oxacilln, nafcillin, or cefazolin

Question 19

Tx of fungal endocarditis (candida or aspergillus)

Answer 19

Amphotericin and valve replacement

Question 20

Tx of staph epidermidis or resistant Staph endocarditis

Answer 20

Vancomycin

Question 21

Tx of Enterococi endocarditis

Answer 21

Ampicillin and gentamicin

Question 22

Indications for surgery in patient with endocarditis

Answer 22

1. CHF or ruptured valve or chordae tendinae
2. Prosthetic valves
3. Fungal endocarditis
4. Abscess
5. AV block
6. Recurrent emboli while on abx

Question 23

Causative organisms in culture negative endocarditis

Answer 23

HACEK (Haemophlus parainfluenzae, Actinobacillus, Cardiobacterum, Eikenella, Kingella)
Coxiella burnetti
Brucella
Bartonella

Question 24

Most common causes of culture negative endocarditis

Answer 24

Coxiella

Bartonella

Question 25

Tx of HACEK group endocarditis

Answer 25

Ceftriaxone

Question 26

Prophylaxis indications of endocarditis

Answer 26

1. Significant cardiac defect (e.g prostetic

Question 27

HIV

Answer 27

retrovirus that targets and destroys CD4 T cells | - infection characterized by high rate of viral replication that leads to progressive decline in CD4 count

Question 28

CD4 count

Answer 28

- indicates degree of immunosuppression | - guides therapy and prophylaxis and helps determine prognosis

Question 29

Viral load

Answer 29

may predict the rate of disease progression | - provides predictions for treatment and gauges response to ARTs

Question 30

HIV: Hx and PE

Answer 30

- acute HIV, pts are often asymptomatic but patients may also present with mononucleosis-like or flu-like symptoms (e.g. fever, lymphadenitis, maculopapular rash) - HIV may present later as night sweats, weight loss, thrush, recurrent infxns or opportunic infxns

Question 31

Diagnosis of HIV

Answer 31

ELISA test (detects serum antibodies) then Western blot as confirmatory tests

Question 32

Baseline eval for HIV should incle:

Answer 32

``` HIV RNA PCR (viral load) CD4 count PPD skin tests Pap smear Mental status exam VDRL/RPR serologies for CMV ```

Question 33

Treatment for HIV

Answer 33

Initiate ART: 1. symptomatic patients (those with AIDS defining illness no matter CD4 count) 2. Patients with CD4 count < 350 3. Pregnant patients 4. Those with HIV specific conditions (e.g. HIV associated nephropathy, neurocognitive deficits)

Question 34

Initial regimen for HIV

Answer 34

2 nucleoside reverse transcriptase inhibitors (NRTIs) plus 1 nonnucleoside reverse transcriptase inhibitor -- most import is select multiple meds (usually 3) to achieve durable treatment response and limit resistance

Question 35

Goal of HIV therapy

Answer 35

Limit viral suppression < 50 copies - after therapy is started CD4 count should be monitored monthly until suppression is achieved and every 3-6 months afterward

Question 36

HIV + with CD4 300 - 500

Answer 36

``` Baceterial infections TB Herpes Simplex Herpes Zoster Vaginal candidiasis Hairy leukoplakia Kaposi's sarcoma ```

Question 37

HIV + with 75 - 175

Answer 37

``` Pneumocytosis Toxoplasmosis Cryptococcus Coccidiomycosis Cryptosporidoios ```

Question 38

HIV < 50

Answer 38

Disseminated MAC infection Histoplasmosis CMV retinitis CNS lymphoma

Question 39

Pregnant HIV + patient is not on ARVs at time of delivery, she should be treated with what meds?

Answer 39

Intrapaerum zidovudine | - infants should recieve AZT for 6 weeks after birth

Question 40

Which is only live vaccine that should be given to HIV patients?

Answer 40

MMR

Question 41

P jiroveci pneumonia (PCP pneumonia)

Answer 41

- prophylaxis indicated at CD4 < 200 prior PCP infection - unexplained fever x 2 weeks - HIV related candidiasis

Question 42

PCP prophylaxis

Answer 42

- single strength TMP-SMX (Bactrim fo | * * discontinue PCP prophylaziz when CD4 > 200 for 3 months

Question 43

Mycobacterium avium complex (MAC)

Answer 43

prophylaxis indicated when CD4 count < 50-100 - treated with weekly azithromycin - discontinue prophylaxis when CD4 count is > 100 for > 6 months

Question 44

Toxoplasma gondii (HIV +)

Answer 44

prophylaxis indicated < 100 with positive IgG serologies | - prophylaxis with double strength Bactrim

Question 45

M tuberculosis (HIV +)

Answer 45

prophylaxis indicated PPD > 5mm - treated with isonizaid x 9 months (+ pyridoxine) or rifampin (4 months) - include pyridoxine with INH-containing regiments `

Question 46

Candida prophylaxis (HIV +)

Answer 46

prophylaxis indicated at multiple recurrences esophagitis prophylaxis: fluconazole oral: nystatin swish and swallow