HIV-associated tuberculosis among a cohort of heterosexual discordant couples in Lusaka, Zambia

The purpose of this study was to determine the association between human immunodeficiency virus (HIV) infection and tuberculosis (TB) among a cohort of heterosexual discordant couples (one partner HIV-positive and the other HIV-negative) enrolled at an HIV prevention and research centre in Lusaka, Zambia. All medical records identified from January 1994 to July 1998 were extensively reviewed. In addition, follow-up visits to local health department and chest clinics and to sputum analyses laboratories were conducted to validate the extracted medical data. The study used a nested approach based on a retrospective study design. The participants with HIV-associated tuberculosis (HAT), when compared with HIV-negative subjects with diagnosis of presumptive tuberculosis, were more likely to have presented with negative sputum analyses, to have been diagnosed with pulmonary tuberculous lesion, to have experienced relapse from tuberculosis, to have never been hospitalized for tuberculosis-related complications, and to have died due to tuberculosis. In addition, 9% of the urban heterosexual discordant couples enrolled in the primary cohort study were positive for presumptive tuberculosis. This study reports the first major impact of HIV infections on the outcomes of tuberculosis among heterosexual discordant couples. However, further research using vigorous methodological criteria is recommended to confirm the above findings.