Sharing cannabis bongs linked to 4x higher tuberculosis risk in Thailand

After adjusting for covariates, smoking and sharing a cannabis bong had an odds ratio of 4.22 (95% CI: 1.47-12.07) for TB. No significant association was found for other types of cannabis consumption. The population-attributable fraction for shared cannabis bongs was 12.16%, compared to 12.62% for tobacco smoking.

Matched case-control study in Songkhla Province, Thailand (2023). 148 TB cases and 117 healthy controls completed face-to-face interviews about cannabis consumption. Multivariate logistic regression estimated odds ratios. Population-attributable fractions calculated.

In TB-endemic countries, sharing smoking devices is a plausible transmission route. This study isolates shared cannabis bong use as a specific risk behavior, distinct from cannabis use in general, which has direct implications for harm reduction messaging.

Following Thailand cannabis legalization in 2022, understanding which specific behaviors carry health risks is critical for targeted harm reduction. This study suggests the TB risk is about sharing the device, not necessarily about cannabis use itself.

Small sample size from one Thai province. Case-control design limits causal inference. Self-reported cannabis use may be inaccurate. Cannot separate the effect of sharing from the effect of bong smoking itself. Cultural context (Thai waterpipe sharing) may not generalize.