Pneumocystis jirovecii in General Population

摘要

The possible presence of Pneumocystis amonghealthy adults was examined by detecting Pneumocystisjirovecii–specific DNA in prospectively obtained oropharyn-geal wash samples from 50 persons without underlyinglung disease or immunosuppression. Pneumocystis car-riage, defined by detecting Pneumocystis DNA by nestedpolymerase chain reaction in 2 independent analyses plussuccessful mitochondrial large subunit ribosomal RNA typ-ing by direct sequencing, was found in 20% of cases. Allcarriers were asymptomatic, anti-HIV negative, and hadnormal total lymphocyte and CD4+ cell counts. A secondsample obtained in the 6-month follow-up was positive in 2of 9 available carriers. Genotype analysis showed differentpolymorphisms; 85A/248C (40%) and 85C/248C (30%)were most frequently observed. This study provides thefirst evidence that P. jirovecii DNA can be frequently detect-ed in the respiratory tract of immunocompetent adults,which agrees with the hypothesis that the general popula-tion could be a reservoir and source of this infection