Association of air pollution with the risk of initial outpatient visits for tuberculosis in Wuhan, China

Objectives Previous studies suggested the association of air pollution with initial Mycobacterium tuberculosis infection and the disease development. However, few studies have been conducted on air pollution and initial tuberculosis (TB) consults using short-interval data. We investigated the weekly association between air pollution and initial TB outpatient visits. Methods We used a Poisson regression model combined with a distributed lag non-linear model to conduct a time-series study with weekly air pollution data and TB cases during 2014-2017 in Wuhan, China. Results A 10 µg/m 3 increase in NO 2 (nitrogen dioxide) was associated with 11.74% (95% CI: 0.70 to 23.98, lag 0-1 weeks), 21.45% (95% CI: 1.44 to 45.41, lag 0-2 weeks) and 12.8% (95% CI: 0.97 to 26.02, lag 0-1 weeks) increase in initial TB consults among all patients with TB, old patients (≥60 years old) and male ones, respectively. A 10 µg/m 3 increase in SO 2 (sulfur dioxide) was associated with -22.23% (95% CI: -39.23 to -0.49, lag 0-16 weeks), -28.65% (95% CI: -44.3 to -8.58, lag 0-16 weeks), -23.85 (95% CI: -41.79 to -0.37, lag 0-8 weeks) and -23.82% (95% CI: -41.31 to -1.11, lag 0-16 weeks) increase in initial TB consults among the total, young (aged 15-59 years old), old and male patients, respectively. In old patients, a 0.1 mg/m 3 increase in CO (carbon monoxide) and a 10 µg/m 3 increase in PM 2.5 (particulate matter) were separately associated with 42.32% (95% CI: 1.16 to 100.22, lag 0-16 weeks) and 17.38% (95% CI: 0.28 to 37.38, lag 0-16 weeks) increases in TB consults. Conclusion Our study first highlighted the importance of weekly association between air pollution and the risk of initial TB consults, which is helpful for the arrangements of TB screening and medical assistance.