CCTN Infection Prevention and Management in Transplant Recipients 1 — Questions and Answers
Question 1: Which prophylactic medication is routinely prescribed to prevent Pneumocystis jirovecii pneumonia (PCP) in solid organ transplant recipients?
- Trimethoprim-sulfamethoxazole (TMP-SMX) (Correct answer)
- Fluconazole
- Valganciclovir
- Dapsone monotherapy
Correct answer: Trimethoprim-sulfamethoxazole (TMP-SMX)
TMP-SMX (Bactrim) is the first-line prophylactic agent for PCP in immunocompromised transplant patients due to its proven efficacy and broad coverage.
Question 2: In a CMV donor-positive/recipient-negative (D+/R-) transplant scenario, what is the recommended management strategy?
- Universal prophylaxis with valganciclovir for 3–6 months (Correct answer)
- Pre-emptive therapy based on weekly CMV PCR monitoring only
- No prophylaxis needed since the recipient has no prior exposure
- Acyclovir prophylaxis for the first 30 days
Correct answer: Universal prophylaxis with valganciclovir for 3–6 months
D+/R- is the highest-risk CMV serostatus combination, requiring universal antiviral prophylaxis (valganciclovir) for 3–6 months post-transplant to prevent primary CMV disease.
Question 3: Which live vaccines are contraindicated in solid organ transplant recipients on maintenance immunosuppression?
- MMR (measles-mumps-rubella) and varicella zoster live vaccine (Correct answer)
- Inactivated influenza and pneumococcal vaccines
- Hepatitis B and recombinant zoster vaccine
- Tetanus, diphtheria, and pertussis (Tdap)
Correct answer: MMR (measles-mumps-rubella) and varicella zoster live vaccine
Live attenuated vaccines such as MMR and live varicella zoster vaccine carry the risk of vaccine-strain infection in immunocompromised patients and are contraindicated post-transplant.
Question 4: BK polyomavirus nephropathy is a significant concern primarily in which type of solid organ transplant recipient?
- Kidney transplant recipients (Correct answer)
- Liver transplant recipients
- Heart transplant recipients
- Lung transplant recipients
Correct answer: Kidney transplant recipients
BK virus predominantly replicates in the urothelium and tubular epithelium, making kidney transplant recipients the population most at risk for BK nephropathy and graft loss.
Question 5: A transplant recipient presents with fever, productive cough, and CT findings showing bilateral ground-glass opacities three months post-transplant. Which organism should be highest on the differential?
- Pneumocystis jirovecii (Correct answer)
- Streptococcus pneumoniae
- Mycobacterium tuberculosis
- Candida albicans
Correct answer: Pneumocystis jirovecii
Ground-glass opacities on CT combined with fever and cough in the 1–6 month post-transplant window are classic for PCP, especially if prophylaxis was discontinued or inadequate.
Question 6: What is the primary mechanism by which trimethoprim-sulfamethoxazole provides prophylaxis against Toxoplasma gondii in transplant recipients?
- It inhibits folate synthesis, which is essential for Toxoplasma replication (Correct answer)
- It disrupts the parasite's cell membrane permeability
- It blocks Toxoplasma entry into host macrophages
- It stimulates innate immune recognition of the parasite
Correct answer: It inhibits folate synthesis, which is essential for Toxoplasma replication
TMP-SMX inhibits dihydrofolate reductase and dihydropteroate synthase, blocking folate synthesis required for Toxoplasma DNA replication, providing concurrent PCP and toxoplasma prophylaxis.
Question 7: During the first month post-transplant, which category of infections predominates and reflects the patient's pre-transplant health status and surgical complications?
- Donor-derived and recipient pre-existing infections, plus surgical-site and nosocomial infections (Correct answer)
- Opportunistic infections from immunosuppression such as CMV and PCP
- Community-acquired respiratory infections from environmental exposure
- Reactivation of latent viral infections like EBV and VZV
Correct answer: Donor-derived and recipient pre-existing infections, plus surgical-site and nosocomial infections
In the first month post-transplant, infections are similar to those in any post-surgical patient and reflect pre-existing conditions, donor-derived pathogens, and hospital-acquired organisms rather than immunosuppression-driven opportunists.
CCTN Infection Prevention and Management in Transplant Recipients 1
Which prophylactic medication is routinely prescribed to prevent Pneumocystis jirovecii pneumonia (PCP) in solid organ transplant recipients?