Infectious Diseases

Question 1

What are the durations of treatment for different pathogens causing bacterial meningitis?

Answer 1

S. pneumonia - 10-14 days
N. meningitidis - 7 days
L. monocytogenes - 21 days

Question 2

Who gets chemoprophylaxis for N. meningitis and with what?

Answer 2

Who - household contacts, sharing sleeping arrangements, healthcare workers with intensive unprotected contact.

What - ceftriaxone 250 mg IM, rifampin 600 mg PO BID x 2d, ciprofloxacin 500 mg PO x 1

Question 3

Who gets immunoprophylaxis for N. meningitis?

Answer 3

Household contacts, sharing sleeping arrangements.

Question 4

Who gets empiric anaerobic coverage for aspiration pneumonia?

Answer 4

Feculent sputum, abscess, empyema.

Question 5

What are risk factors for MRSA?

Answer 5

Healthcare - recent hospitalization, resident of LTC home, recent surgery, IHD
Other - HIV, IVDU, prior antibiotics.

Question 6

What are risk factors for pseudomonas?

Answer 6

Healthcare (ICU stay, bedridden, invasive devices), prior use of broad-spectrum antibiotics in last 3 months, lung disease (CF, bronchiectasis, COPD exacerbations), immunocompromise (HIV, neutropenic, stem cell transplant).

Question 7

What are the most specific tests for early HIV infection?

Answer 7

Genital ulcers > weight loss

Question 8

How do define and treat severe pneumocystis pneumonia?

Answer 8

Severe: PaO2<70% or A-a gradient >35.

Treat:
Septra 15-20 mg/kg IV x 21d,
Prednisone 40 mg PO BID x 5d then 20 mg PO BID x 5d then 20 mg PO daily x 11d.

Question 9

How do you treat toxoplasmosis in an HIV + patient?

Answer 9

Sulfadiazine and pyrimethamine (with leucovorin) for 6 weeks.

Question 10

Who should be tested for latent TB?

Answer 10

1. Contact with someone with active TB.
2. Travelling to TB endemic country.
3. Immigrant from TB endemic country.
4. Health care workers.
5. LTC home or prison resident.
6. Homeless.
7. Aboriginal.
8. IV drug user.

Question 11

Who tests positive with a TBST > 5 mm (six total)?

Answer 11

1. HIV +
2. Contact with infectious case in past 2 years.
3. Fibronodular disease on CXR.
4. Organ transplantation.
5. ESRD.
6. Drugs (TNF-alpha, steroids).

Question 12

Who requires steroids as part of TB treatment?

Answer 12

TB meningitis and TB pericarditis.

Question 13

What are 5 class one indications for early surgical intervention for infective endocarditis?

Answer 13

1. Persistent fever or bacteremia >5-7d after appropriate antibiotics.
2. Lt sided IE from S. aureus, fungus, or resistant organism.
3. Valve dysfunction with signs of heart failure.
4. Heart block, root/annular abscess, penetrating lesion.
5. Infected PPM or ICD or lead.

Question 14

Who should be considered for IE prophylaxis?

Answer 14

1. Prior IE.
2. Any prosthetic valve (including TAVR).
3. Congenital heart disease (unrepaired, repaired within last 6 months, or repaired with residual deficits).
4. Heart transplant with valvulopathy.

Question 15

Name three populations who should get empiric antibiotics for bloody diarrhea.

Answer 15

1. Sick immunocompromised.
2. Immunocompetent with fever >38.5C and recent travel.
3. Immunocompetent with signs of shigella dysentery (frequent scant movements, pain, tenesmus, fever).

Question 16

What are the elements of treatment of necrotizing fasciitis?

Answer 16

1. Urgent plastic surgery consult.
2. Type I NF empiric tx: piptazo + vanco
3. Type II NF empiric tx: clindamycin
4. Consider IVIG if shock or pre-op

Question 17

What is the OVIVA trial?

Answer 17

Showed non-inferiority of oral vs intravenous antibiotics for bone and joint infections.

Question 18

What are the most sensitive and specific tests for malaria diagnosis?

Answer 18

Sensitive: No fever
Specific: High bilirubin, splenomegaly, low platelets, fever

Question 19

What degree of parasitemia constitutes severe malaria?

Answer 19

2%

Question 20

What are key features of dengue fever?

Answer 20

Fever, severe mylagias, retro-orbital pain, maculopapular rash, cytopenias, NSAIDs make symptoms worse.

Question 21

What are key features of chikungunya disease?

Answer 21

Fever, polyarthralgias, lymphopenia, maculopapular rash.

Question 22

What are key features of typhoid fever?

Answer 22

Flu like symptoms, rose spots, relative bradycardia, constipation, abdominal pain.

Question 23

How do you treat typhoid?

Answer 23

Uncomplicated: fluoroquinolone (resistance in Asia) or azithromycin.
Severe: Ceftriaxone.

Question 24

Which four diseases do you screen for before starting steroids?

Answer 24

1. TB - prednisone > 15 mg/d >4 weeks and 1+ TB risk factors (r/o active, treat latent, INH x 9 mo).
2. Hep B - prednisone > 7.5 mg/d.
3. Pneumocystis - prednisone > 20 mg/d >4-8 weeks (Septra one DS daily)
4. Strongyloides - anyone from endemic country.

Question 25

List 6 opportunistic infections occur at CD4 count <20

Answer 25

1. Cutaneous Kaposi sarcoma. 2. PJP. 3. Endemic fungi (histo, coccidiosis, blasto). 4. Non-endemic fungi (cryptococcus). 5. HIV-myelopathy (paraplegia). 6. Cancer (NHL, anal, vaginal, cervical, liver)

Question 26

What viral load count precludes vaginal delivery?

Answer 26

>1000 copies/mL

Question 27

What are three features of tertiary syphilis?

Answer 27

1. Cardiovascular - aortitis. 2. Neurologic - tabes dorsalis, paresis. 3. Gummatous disease.

Question 28

What is a classic finding of mucormycosis?

Answer 28

Black eschar in nasal mucosa or palate of a diabetic patient.

Question 29

What organism most likely causes invasive otitis externa?

Answer 29

Pseudomonas aeruginosa.

Question 30

Which patients get tetanus vaccine and immunoglobulin?

Answer 30

Vaccine: clean/minor wound with last vaccine unknown or >10 years ago, dirty and/or major wound with last vaccine unknown or >5 years ago. Immunoglobulin: dirty and/or major wound with unknown vaccine status.

Question 31

How long does Lyme IgM convert to IgG?

Answer 31

30 days.

Question 32

How do you treat erythema migrans?

Answer 32

Doxycycline for 14 days.

Question 33

How do you treat ventriculitis?

Answer 33

Remove all hardware, place external drain, vanco + mero or ceftaz IV, treat for 10-14d (GP) or 21d (GN), new shunt inserted after 7-10d negative CSF cultures.

Question 34

List 4 ways to prevent ventilator-associated pneumonia.

Answer 34

1. Bed 30-45 degrees. 2. Sedation vacation daily. 3. Oral care with chlorhexidine. 4. Early mobilization.

Question 35

Which strains of candida are resistant to fluconazole?

Answer 35

C. krusei and C. glabrata.

Question 36

What are risk factors for listeriosis?

Answer 36

1. Age>50 2. Immunocompromise 3. Alcoholic 4. Pregnancy 5. Diabetes 6. ESRD 7. Iron overload 8. Active liver disease.

Question 37

What is the differential for leptomeningeal enhancement?

Answer 37

TB, sarcoid, mets