Medicine - Medicine - Infectious Diseases
A Case-Control Study Investigating the Intersection between Tobacco use, TB and HIV
The epidemics of tobacco use, HIV and tuberculosis (TB) are responsible for millions of deaths worldwide annually, and persons living in the developing world are especially at risk. While the association between tobacco use and TB disease has been widely investigated, it remains unclear if tobacco use is more prevalent in HIV-infected patients with TB compared to HIV patients with no TB. We wish to establish whether the impact of smoking on TB in HIV -infected patients is restricted to the lungs or is more pervasive, affecting other organ systems equally.The overall objective of this proposal is to investigate the association between tobacco use and tuberculosis in HIV-infected males in Johannesburg, South Africa where rates of all three epidemics are extremely high. We will conduct a case-control study restricting all participants to HIV-infected men from Soweto. There will be two Case groups: 1) HIV-infected males with confirmed pulmonary tuberculosis and 2) HIV-infected males with extra-pulmonary TB and no evidence of pulmonary TB. The Control group will be HIV-infected males without TB. We will estimate nicotine exposure in all cases using hair samples, a biomarker that is relatively easy to collect and store and provides reliable exposure data of the previous month. We will also collect data for factors that may modify the association between tobacco and TB among HIV -infected patients including alcohol exposure and socioeconomic status.Tobacco exposure is now recognized as an emerging threat to public health worldwide. The proposed study will provide preliminary data for a future larger study investigating further components of the intersection between tobacco use, tuberculosis and HIV-infection.
Neil Martinson, MBBCH, MPH