Airborne spread of Pneumocystis jirovecii.

In this issue of the journal, Choukri et al [1] state that their study provides the first quantitative data on the spread of Pneumocystis jirovecii in exhaled air from infected patients. There are additional data in prior studies using air samples collected in rooms of patients diagnosed as having P. jirovecii showing that not only could the organisms be detected but also their types correlated with types demonstrated in patient samples [2]. The air samples were compared with samples from areas close to the rooms studied and other control areas. We believe that airborne transmission was demonstrated with the samples and methods used. Because airborne transmission for animals has been well established, the next step was to show that transmission occurred in humans as well. It is important that these addi-