A highly transmissible tuberculosis outbreak: the importance of bars

Area of Science:

• Epidemiology
• Public Health
• Infectious Disease Transmission

Background:

• Tuberculosis (TB) transmission in social venues like bars is challenging to investigate.
• Understanding transmission dynamics in non-traditional settings is crucial for public health interventions.

Purpose of the Study:

• To describe a significant tuberculosis outbreak originating in a company bar and extending to other leisure settings.
• To assess the risk of latent tuberculosis infection (LTBI) among contacts in various social environments.

Main Methods:

• A descriptive study design was employed to investigate the TB outbreak.
• Contact tracing was conducted within the workplace bar (five circles) and a social network of neighborhood bars.
• Tuberculin skin tests (TST) and chest X-rays were used to identify TB cases and LTBI.

Main Results:

• Five new TB cases were identified among 316 contacts at the workplace bar, with an LTBI prevalence of 57.9%.
• LTBI prevalence decreased with increasing distance from the index case within the workplace bar (96.0% in the first circle to 46.5% in the fifth).
• Two TB cases and a 51.7% LTBI prevalence were found among 58 contacts in neighborhood bars; two children of a secondary case also became ill.

Conclusions:

• Bars and similar social venues can serve as significant locations for tuberculosis transmission.
• These popular social gathering spots should be recognized as potential areas for TB exposure and targeted for public health surveillance.