Tobacco Smoking and Tuberculosis among Men Living with HIV in Johannesburg, South Africa: A Case-Control Study

Abstract

Setting: Although there is ample evidence that smoking increases the risk of tuberculosis (TB), the magnitude of impact on TB risk among HIV-infected persons is poorly described. Given that a high proportion of patients with TB are co-infected with HIV in South Africa, the risks arising from the intersection of smoking, TB, and HIV/AIDS have key relevance for tobacco control policies.

Objective: To evaluate the association of pulmonary tuberculosis (PTB) with current tobacco smoking among men with HIV in South Africa.

Design: Case-control study of antiretroviral therapy naïve men with confirmed HIV-infection in Johannesburg. Cases had laboratory-confirmed PTB and controls had no evidence of active TB. Participants were interviewed to collect detailed smoking histories.

Results: We enrolled 146 men diagnosed with PTB and 133 controls. Overall, 33% of participants were currently smoking, defined as smoking a cigarette within 2 months (34% cases vs. 32% controls, p = 0.27). Median CD4 count was lower (60 vs. 81 cells/mm3, P = 0.03) and median viral load was higher (173 vs. 67 copies/ul per thousand, P<0.001) among cases versus controls. In adjusted analyses, current smoking tripled the odds of PTB (aOR 3.2; 95%CI: 1.3-7.9, P = 0.01) and former smoking nearly doubled the odds of PTB (aOR 1.8; 95%CI 0.8-4.4, P = 0.18) compared to never smoking.

Conclusions: Males with HIV that smoke are at greater odds for developing PTB than non-smokers. Extensive smoking cessation programs are needed to reduce odds of TB and promote health among adults living with HIV.