Persistent Mycobacterium tuberculosis bioaerosol release in a tuberculosis-endemic setting.

UNLABELLED: Pioneering studies linking symptomatic disease and cough-mediated release of Mycobacterium tuberculosis ( Mtb ) established the infectious origin of tuberculosis (TB), simultaneously informing the pervasive notion that pathology is a prerequisite for Mtb transmission. Our prior work has challenged this assumption: by sampling TB clinic attendees, we detected equivalent release of Mtb -containing bioaerosols by confirmed TB patients and individuals not receiving a TB diagnosis, and we demonstrated a time-dependent reduction in Mtb bioaerosol positivity during six-months' follow-up, irrespective of anti-TB chemotherapy. Now, by extending bioaerosol sampling to a randomly selected community cohort, we show that Mtb release is common in a TB-endemic setting: of 89 participants, 79.8% (71/89) produced Mtb bioaerosols independently of QuantiFERON-TB Gold status, a standard test for Mtb infection; moreover, during two-months' longitudinal sampling, only 2% (1/50) were serially Mtb bioaerosol negative. These results necessitate a reframing of the prevailing paradigm of Mtb transmission and infection, and may explain the current inability to elucidate Mtb transmission networks in TB-endemic regions.

SUMMARY: Elucidating chains of Mycobacterium tuberculosis transmission is limited by a dependence on linking sputum-positive tuberculosis cases. Here, we report persistent M. tuberculosis bioaerosol release in the majority of a randomly selected community cohort. The contribution to tuberculosis transmission is unknown.