Effect of tuberculosis on the survival of HIV-infected men in a country with low tuberculosis incidence

Evidence regarding the effect of tuberculosis (TB) on HIV disease progression at the population level remains inconclusive. We estimated the effect of incident TB on time to AIDS-related death, using a marginal structural Cox model. Between 1984 and 2005, 2882 HIV-infected men in the Multicenter AIDS Cohort Study contributed 21 914 person-years while followed for a median of 5.4 years. At study entry, the median CD4 cell count and HIV-1 RNA viral load were 533 cells/microl (interquartile range: 365-737) and 12, 953 copies/ml (interquartile range: 2453-48 540), respectively. This study was performed in a setting with a modest exposure to HAART; 8295 of 23 801 (35%) person-years were followed during the HAART era. Fifteen men incurred incident TB, yielding a TB incidence of 7 (95% confidence interval: 4-14) per 10 000 person-years and 1072 died of AIDS-related causes. Accounting for potential confounders, including CD4 cell count and viral load, the hazard of AIDS-related death was 2.4 times more for the person-time with TB compared to the person-time without TB (95% confidence interval: 1.2-4.7). Results underscore the importance of avoiding TB by using preventive interventions such as treatment of latent TB infection, particularly in populations with a large prevalence of HIV/TB co-infected individuals.