BCACP Infectious Disease and Immunization Management 4 — Questions and Answers
Question 1: A patient with HIV on antiretroviral therapy has a CD4 count of 150 cells/μL. Which opportunistic infection prophylaxis is MOST indicated?
- Trimethoprim-sulfamethoxazole for Pneumocystis jirovecii pneumonia (Correct answer)
- Fluconazole for cryptococcal meningitis
- Azithromycin for Mycobacterium avium complex
- Acyclovir for HSV reactivation
Correct answer: Trimethoprim-sulfamethoxazole for Pneumocystis jirovecii pneumonia
TMP-SMX prophylaxis for PCP is indicated when CD4 count falls below 200 cells/μL.
Question 2: Which hepatitis B vaccine schedule is recommended for adults with diabetes mellitus aged 60 years or older?
- 2-dose series (Heplisav-B) is preferred
- Vaccination should be at the clinician's discretion based on risk (Correct answer)
- 3-dose series is mandatory regardless of prior vaccination status
- Vaccination is contraindicated in this age group
Correct answer: Vaccination should be at the clinician's discretion based on risk
ACIP recommends hepatitis B vaccination for adults 19–59 with diabetes and at the clinician's discretion for those ≥60 years.
Question 3: A patient is prescribed rifampin for latent TB. Which drug interaction requires the most urgent counseling?
- Warfarin — reduced anticoagulant effect (Correct answer)
- Metformin — increased hypoglycemia risk
- Lisinopril — additive hypotension
- Omeprazole — reduced rifampin absorption
Correct answer: Warfarin — reduced anticoagulant effect
Rifampin is a potent CYP450 inducer that significantly reduces warfarin levels, increasing thromboembolism risk.
Question 4: Which statement best describes the role of oseltamivir in outpatient influenza management?
- Most beneficial when initiated within 48 hours of symptom onset (Correct answer)
- Equally effective regardless of time to initiation
- Should be withheld until rapid flu test is confirmed positive
- Indicated only for patients with severe immunocompromise
Correct answer: Most beneficial when initiated within 48 hours of symptom onset
Oseltamivir reduces duration and severity of influenza most effectively when started within 48 hours of symptom onset.
Question 5: A 35-year-old pregnant woman at 28 weeks asks about Tdap vaccination. What is the correct guidance?
- Administer Tdap during each pregnancy, preferably between 27–36 weeks gestation (Correct answer)
- Defer Tdap until postpartum to avoid fetal harm
- Tdap is contraindicated in pregnancy
- Only administer if the patient has never received Tdap before
Correct answer: Administer Tdap during each pregnancy, preferably between 27–36 weeks gestation
ACIP recommends Tdap during every pregnancy, ideally at 27–36 weeks, to provide neonatal pertussis protection via maternal antibody transfer.
Question 6: A patient with recurrent UTIs requests prophylaxis. Which regimen is evidence-based for continuous antibiotic prophylaxis?
- Nitrofurantoin 50–100 mg daily at bedtime (Correct answer)
- Ciprofloxacin 500 mg twice daily
- Amoxicillin-clavulanate 875 mg daily
- Doxycycline 100 mg twice daily
Correct answer: Nitrofurantoin 50–100 mg daily at bedtime
Nitrofurantoin at low doses taken nightly is a well-established option for continuous prophylaxis of recurrent uncomplicated UTIs.
Question 7: Which vaccine is CONTRAINDICATED in a patient receiving high-dose corticosteroids (prednisone ≥20 mg/day for >2 weeks)?
- Zoster recombinant (Shingrix)
- Live attenuated influenza vaccine (LAIV) (Correct answer)
- Inactivated influenza vaccine (IIV)
- Pneumococcal polysaccharide vaccine (PPSV23)
Correct answer: Live attenuated influenza vaccine (LAIV)
LAIV is a live vaccine contraindicated in immunocompromised patients, including those on high-dose systemic corticosteroids.
BCACP Infectious Disease and Immunization Management 4
A patient with HIV on antiretroviral therapy has a CD4 count of 150 cells/μL.
Which opportunistic infection prophylaxis is MOST indicated?