Persistent Mycobacterium tuberculosis bioaerosol release in a tuberculosis-endemic setting

Area of Science:

• Microbiology and Infectious Diseases
• Public Health and Epidemiology

Background:

• Traditional understanding posits that symptomatic tuberculosis (TB) disease is necessary for Mycobacterium tuberculosis (Mtb) transmission.
• Previous research indicated Mtb aerosol release by individuals without a TB diagnosis, challenging the necessity of active pathology for transmission.
• The role of subclinical Mtb shedding in community-level transmission dynamics remains largely unexplored.

Approach:

• Extended bioaerosol sampling to a randomly selected community cohort in a TB-endemic region.
• Assessed Mtb bioaerosol production in relation to TB diagnosis status and QuantiFERON-TB Gold (QFT-Gold) results.
• Conducted longitudinal sampling over two months to evaluate serial Mtb bioaerosol negativity.

Key Points:

• A high prevalence (79.8%) of Mtb bioaerosol release was observed in the community cohort, irrespective of QFT-Gold status.
• Serial sampling revealed minimal participants (2%) remained consistently Mtb bioaerosol negative over two months.
• These findings demonstrate that Mtb release is a common phenomenon within communities, not solely linked to diagnosed TB.

Conclusions:

• The study necessitates a paradigm shift in understanding Mtb transmission, highlighting common aerosol shedding beyond symptomatic disease.
• Widespread Mtb release may explain the difficulties in tracing transmission networks in TB-endemic areas.
• Further research is needed to understand the implications of subclinical Mtb shedding for TB control strategies.