American Board of Internal Medicine (ABIM) Certification Practice Exam 2026 - Free ABIM Practice Questions and Study Guide

Transplant patients are at particularly high risk for Pneumocystis jirovecii infections during the first 6 to 12 months post-transplant due to their immunosuppressed state. After organ transplantation, patients typically undergo immunosuppressive therapy to prevent organ rejection. This immune suppression, particularly in the early post-transplant period, significantly increases their susceptibility to opportunistic infections.

Pneumocystis jirovecii pneumonia (PJP) is a common and potentially severe infection in this population. Prior to the widespread use of prophylactic treatment, PJP was a leading cause of morbidity and mortality among transplant recipients, especially in the first year. The risk is most pronounced as basic immune defenses are compromised and the patient may not have mounting responses to infections.

While all the infection types mentioned can occur in transplant patients due to immune suppression, Pneumocystis jirovecii is specifically notable for its association with the timing of immunosuppressive therapy initiation, necessitating preventive measures such as prophylactic antibiotics to mitigate the risk during those crucial first months. In contrast, while viral, bacterial, and fungal infections are also risks, they may not be as specifically highlighted in the same timeframe as PJP.