A Cluster of Pneumocystis Infections Among Renal Transplant Recipients: Molecular Evidence of Colonized Patients as Potential Infectious Sources of Pneumocystis jirovecii

Abstract

The results provide to our knowledge the first data on the role of colonized patients as potential sources of P. jirovecii in a context of nosocomial acquisition of the fungus.

Epidemiological Outbreaks of Pneumocystis jirovecii Pneumonia Are Not Limited to Kidney Transplant Recipients: Genotyping Confirms Common Source of Transmission in a Liver Transplantation Unit

“…In addition, our findings clearly support the conclusion that liver transplant patients P1 to P4 were all infected by a single genotype of P. jirovecii. This conclusion seems robust because, as shown by the phylogenetic tree, data for the three loci combined were sufficient to discriminate between 24 unrelated P. jirovecii isolates (10). To our knowledge, this is the first genotypic demonstration of clustered PCP limited only to liver transplant patients (24), whereas numerous studies have reported similar findings for kidney recipients (6,10,18), especially in France (10).…”

“…It is responsible for a severe respiratory disease, Pneumocystis jirovecii pneumonia (PCP) (1,20). One potential route of infection is currently believed to be patient-to-patient transmission mediated by airborne droplets (1), and the hypothesis related to contamination from an environmental source has largely been rejected (9,10).…”

“…Globally, the epidemiology of this disease has always been difficult to study (21,23,28,29), mainly due to the lack of easy-to-perform methods of culture and because alternative powerful and informative techniques have not been available in all microbiology laboratories (30). However, MLST is now used widely to investigate nosocomial PCP outbreaks and is generally considered the gold standard (6,10,11,18,31). Recently, Maitte et al showed that a simple scheme relying on three loci, SOD, mt26S, and CYB, provides sufficient discrimination to be used reliably for epidemiological investigations of PCP outbreaks (11).…”

“…These techniques are not suitable for investigating the transmission routes of P. jirovecii (1,9) or for epidemiological investigations of a PCP outbreak (10).…”

Combined Quantification of Pulmonary Pneumocystis jirovecii DNA and Serum (1→3)-β- d -Glucan for Differential Diagnosis of Pneumocystis Pneumonia and Pneumocystis Colonization

“…It has been shown that the fungus may play a role in the progression of underlying lung diseases or in the development of PCP in colonized patients (4). It also has been recently shown that colonized patients may act as potential infectious sources (37).…”