Outbreak of Pneumocystis Pneumonia in Renal and Liver Transplant Patients Caused by Genotypically Distinct Strains of Pneumocystis jirovecii

TY - JOUR

T1 - Outbreak of Pneumocystis Pneumonia in Renal and Liver Transplant Patients Caused by Genotypically Distinct Strains of Pneumocystis jirovecii

AU - Rostved, Andreas A

AU - Sassi, Monica

AU - Kurtzhals, Jørgen A L

AU - Sørensen, Søren Schwartz

AU - Rasmussen, Allan

AU - Ross, Christian

AU - Gogineni, Emile

AU - Huber, Charles

AU - Kutty, Geetha

AU - Kovacs, Joseph A

AU - Helweg-Larsen, Jannik

PY - 2013/11/15

Y1 - 2013/11/15

N2 - BACKGROUND: An outbreak of 29 cases of Pneumocystis jirovecii pneumonia (PCP) occurred among renal and liver transplant recipients (RTR and LTR) in the largest Danish transplantation centre between 2007 and 2010, when routine PCP prophylaxis was not used. METHODS: P. jirovecii isolates from 22 transplant cases, 2 colonized RTRs, and 19 Pneumocystis control samples were genotyped by restriction fragment length polymorphism and multilocus sequence typing analysis. Contact tracing was used to investigate transmission. Potential risk factors were compared between PCP cases and matched non-PCP transplant patients. RESULTS: Three unique Pneumocystis genotypes were shared among 19 of the RTRs, LTRs, and a colonized RTR in three distinct clusters, two of which overlapped temporally. In contrast, Pneumocystis control samples harbored a wide range of genotypes. Evidence of possible nosocomial transmission was observed. Among several potential risk factors, only cytomegalovirus viremia was consistently associated with PCP (P=0.03; P=0.009). Mycophenolate mofetil was associated with PCP risk only in the RTR population (P=0.04). CONCLUSION: We identified three large groups infected with unique strains of Pneumocystis and provide evidence of an outbreak profile and nosocomial transmission. LTRs may be infected in PCP outbreaks simultaneously with RTRs and by the same strains, most likely by interhuman transmission. Patients are at risk several years after transplantation, but the risk is highest during the first 6 months after transplantation. Because patients at risk cannot be identified clinically and outbreaks cannot be predicted, 6 months of PCP chemoprophylaxis should be considered for all RTRs and LTRs.

AB - BACKGROUND: An outbreak of 29 cases of Pneumocystis jirovecii pneumonia (PCP) occurred among renal and liver transplant recipients (RTR and LTR) in the largest Danish transplantation centre between 2007 and 2010, when routine PCP prophylaxis was not used. METHODS: P. jirovecii isolates from 22 transplant cases, 2 colonized RTRs, and 19 Pneumocystis control samples were genotyped by restriction fragment length polymorphism and multilocus sequence typing analysis. Contact tracing was used to investigate transmission. Potential risk factors were compared between PCP cases and matched non-PCP transplant patients. RESULTS: Three unique Pneumocystis genotypes were shared among 19 of the RTRs, LTRs, and a colonized RTR in three distinct clusters, two of which overlapped temporally. In contrast, Pneumocystis control samples harbored a wide range of genotypes. Evidence of possible nosocomial transmission was observed. Among several potential risk factors, only cytomegalovirus viremia was consistently associated with PCP (P=0.03; P=0.009). Mycophenolate mofetil was associated with PCP risk only in the RTR population (P=0.04). CONCLUSION: We identified three large groups infected with unique strains of Pneumocystis and provide evidence of an outbreak profile and nosocomial transmission. LTRs may be infected in PCP outbreaks simultaneously with RTRs and by the same strains, most likely by interhuman transmission. Patients are at risk several years after transplantation, but the risk is highest during the first 6 months after transplantation. Because patients at risk cannot be identified clinically and outbreaks cannot be predicted, 6 months of PCP chemoprophylaxis should be considered for all RTRs and LTRs.

U2 - 10.1097/TP.0b013e3182a1618c

DO - 10.1097/TP.0b013e3182a1618c

M3 - Journal article

C2 - 23903011

SN - 0041-1337

VL - 96

SP - 834

EP - 842

JO - Transplantation

JF - Transplantation

IS - 9

ER -