Pneumocystis colonization is highly prevalent in the autopsied lungs of the general population

Abstract

Increasing reports of Pneumocystis DNA in noninvasive respiratory specimens from immunocompetent asymptomatic adults and the characteristic lung tropism of Pneumocystis suggest that asymptomatic pulmonary infections with Pneumocystis occur after primary infection. However, studies searching for Pneumocystis in the autopsied lungs of healthy immunocompetent adults have not met with success. Methods. Lungs of people who died of violent causes (accidents, homicide, and suicide) and of nonviolent causes (diseases causing a rapid demise in the street) in Santiago, Chile-for whom an autopsy was legally required-were examined for Pneumocystis by nested polymerase chain reaction (PCR) DNA amplification of the mitochondrial large subunit ribosomal RNA-specific P. jirovecii gene and immunofluorescent microscopic analysis. Lung tissue concentration methods and analysis of ∼3% of the weight of the right upper lobe (RUL) were needed to reach the sensitivity threshold of the assays. Individuals dete