Humans Are Selectively Exposed to Pneumocystis jirovecii

Abstract

Environmental exposure has a significant impact on human health. While some airborne fungi can cause life-threatening infections, the impact of environment on fungal spore dispersal and transmission is poorly understood. The democratization of shotgun metagenomics allows us to explore important questions about fungal propagation. We focus on Pneumocystis, a genus of host-specific fungi that infect mammals via airborne particles. In humans, Pneumocystis jirovecii causes lethal infections in immunocompromised patients if untreated, although its environmental reservoir and transmission route remain unclear. Here, we attempt to clarify, by analyzing human exposome metagenomic data sets, whether humans are exposed to different Pneumocystis species present in the air but only P. jirovecii cells are able to replicate or whether they are selectively exposed to P. jirovecii. Our analysis supports the latter hypothesis, which is consistent with a local transmission model. These data also suggest that healthy carriers are a major driver for the transmission.

No Change of Pneumocystis jirovecii Pneumonia after the COVID-19 Pandemic: Multicenter Time-Series Analyses

“…P. jirovecii was detected in air samples within 1 to 8 m from patients with PCP or P. jirovecii colonization and intensive care unit (ICU) HCWs, suggesting airborne spread [32,34,36,[41][42][43]. Additionally, recent analyses with metagenomic data sets have focused on the frequent air shedding of P. jirovecii and their transmission from PCP-confirmed patients, supporting early epidemiologic data [44].…”

Risk of Pneumocystis jirovecii Pneumonia among Solid Organ Transplant Recipients: A Population-Based Study

“…Notably, CD4+ lymphocyte count <200 cells/μL is the primary risk factor for PJP presentation in these immunocompromised patients [ 25 ]. Additionally, recent analyses of available metagenomic data sets have focused on the frequent air shedding of Pneumocystis jirovecii and it transmission from PJP-confirmed patients, supporting early epidemiologic analysis data [ 26 ].…”

Exposome-based public health interventions for infectious diseases in urban settings

“…Although this was not a systematic review of the literature on the topic, it illustrated the level of attention infectious diseases have received among exposome studies. Notwithstanding, there were two studies that included measurements of pathogens as exposures in personal exposure monitoring schemes ( Cissé et al, 2020 , Jiang et al, 2018 ). Moreover, infectious diseases have been described as components of the mixture of exposures in association with physiological aspects of infection to SARS-CoV-2 in a commentary and a review article ( Land, 2020 , Naughton et al, 2020 ).…”