Background: Outbreaks of Pneumocystis jirovecii pneumonia (PCP) in kidney transplant recipients are frequently reported worldwide. However, the general guidelines propose only short-term prophylaxis with trimethoprim-sulfamethoxazole after kidney transplantation. We experienced 3 PCP outbreaks in the last 10 years despite providing the recommended prophylaxis. The purpose of this study was to find a prophylaxis regimen that could successfully prevent future PCP outbreaks in immunosuppressed kidney transplant recipients.
Methods: Occurrence of PCP at our hospital since 2004 was reviewed. A total of 48 cases were diagnosed from July 2004 through December 2014. Genotypes of P. jirovecii were determined in these cases.
Results: Three PCP outbreaks by 3 different genotypes of P. jirovecii in each outbreak occurred with 2-year intervals in last 10 years. Molecular analysis showed that each intraoutbreak was caused by identical P. jirovecii, whereas interoutbreaks were caused by different genotypes. Although short-term prophylaxis was provided to all kidney recipients after each outbreak after identification of a single PCP case, additional outbreaks were not prevented because the universal prophylaxis had already been completed when new case of PCP emerged.
Conclusions: The contagious nature of P. jirovecii allows easy development of outbreaks of PCP in immunosuppressed kidney transplant recipients. Although the universal short-term prophylaxis is effective in controlling ongoing outbreak, lifelong prophylaxis of kidney transplant recipients should be considered to prevent new outbreaks.