Impact of tobacco smoking on tuberculosis recurrence in Uganda

Background Previous research has identified tobacco smoking as a risk factor for tuberculosis (TB) recurrence. The purpose of this analysis is to evaluate the association between smoking and TB recurrence among patients who completed TB treatment at an urban clinic in Kampala, Uganda.

Methods We conducted a retrospective review of records of adult TB patients who participated in the Kawempe District Household Contact Study from 2002–2009. TB recurrence was defined as a culture of M. tuberculosis from a patient who was declared cured of his/her initial TB episode. The associations between smoking and other risk factors for TB recurrence among this population were examined.

Results Of the 538 patients who completed TB treatment, 33 (6.1%) had a TB recurrence and 98 (18.2%) had ever smoked. Of those who smoked 13.3% had a recurrence of TB compared to 4.6% of those who had never smoked (P = 0.001). After univariate analysis, smoking was significantly associated with recurrence (OR=2.7; 95% CI = 1.4, 5.1). Positive HIV status, age 35+, male gender, cavitation, and fibrosis at end of treatment were also associated with TB recurrence. After multivariate analysis, smoking (aOR=2.3; 95% CI = 1.1, 5.9) and fibrosis at end of treatment (aOR=2.6; 95% CI = 1.4, 9.1) were independently associated with TB recurrence.

Conclusion Tobacco consumption is increasing in developing countries and smoking cessation during and after TB treatment is necessary to help prevent TB recurrence.