THE EFFECT OF HUMAN-IMMUNODEFICIENCY-VIRUS TYPE-1 ON THE INFECTIOUSNESS OF TUBERCULOSIS

Setting: Developing country tertiary referral hospital plus catchment community. Objective: To determine the infectiousness of culture-confi rmed pulmonary tuberculosis in patients infected with Human Immunodefi ciency Virus type-1 (HIV-1). Design: Comparison of the incidence of tu berculosis and the prevalence of tuberculin skin test positivity among the household contacts of both HIV-1 positive and negative cases with pulmonary tuberculosis. Results: Of 255 contacts of HIV-1 negative in dex cases, 2 were HIV-1 positive and of 102 contacts of HIV-1 positive index cases, 14 were HIV-1 positive (odds ratio (OR) = 20.0 95% Confi dence Interval (CI) 4. 193). 21 cases of tuberculosis were diagnosed a mong contacts, of whom 3 were HIV-1 positive. The overall unadjusted O R for tuberculosis among contacts of HIV-1 positive index cases was 1. 6 (95% CI 0.6-4.3) compared to contacts of HIV-1 negative index cases. Amongst HIV-1 negative contacts alone the OR was 1.5 (95% CI 0.4-4.4) . In this group the best predictors of tuberculosis among contacts wer e female sex of the index case (OR = 3.4 95% CI 1.1-12), sharing the s ame bed as the index case (OR = 2.6 95% CI 0.9-7.4), and contact's age less than 5 years (OR = 3.3 95% CI 1.1-9.5). HIV-1 positive contacts were more likely to develop tuberculosis than HIV-1 negative contacts (OR = 4.1 95% CI 0.7-17). Tuberculin skin test positivity rates were t he same among the HIV-1 negative contacts of HIV-1 positive and negati ve index cases (OR = 1.1 CI 0.7-1.6). Conclusions: HIV-1 associated pu lmonary tuberculosis is not more infectious than tuberculosis alone. T he presence of HIV-1 in a community does not mandate a change in the m anagement of contacts of patients with pulmonary tuberculosis.