Preventive chemotherapy for HIV-associated tuberculosis in Uganda: an operational assessment at a voluntary counselling and testing centre

Abstract

To assess the operational aspects of isoniazid preventive chemotherapy (IPT) for tuberculosis in persons dually infected with HIV and Mycobacterium tuberculosis identified at an independent HIV voluntary counselling and testing centre in Kampala, Uganda. HIV-infected persons were counselled, had active tuberculosis excluded by medical examination, and were offered purified protein derivative (PPD) skin testing. PPD-positive persons were offered isoniazid 300 mg daily for 6 months. Drugs were supplied, and toxicity and compliance were assessed monthly. Utilization of service, cost, and sustainability were also assessed. Between 14 June 1991 and 30 September 1992, 9862 persons tested HIV-positive. Of 5594 HIV-infected clients who returned to collect test results, only 1524 (27%) were enrolled. Of those, 1344 were tuberculin-tested (88%); 180 were not tested because of active tuberculosis, serious illnesses, refusal, and other reasons. Of the 1344, 250 (19%) did not return for test reading and 515 were negative (47% of tests read). Of 579 tuberculin-positive persons, 59 (10%) were excluded from preventive chemotherapy because of tuberculosis and other respiratory illnesses. Of 520 persons given isoniazid, 62% collected at least 80% of their drug supplies. No major toxicity was observed. One case of tuberculosis occurred in the first month of treatment. Cost of HIV counselling and testing was US $18.54 per person and cost of follow-up counselling and social support was US $7.89. Important factors were identified which caused attrition, such as limited motivation by counsellors to discuss tuberculosis issues during HIV pre- and post-test counselling, insufficient availability of medical screening, shifting of sites to collect pills, and frequent tuberculin-negative tests. Active tuberculosis among 6% of persons screened suggests that voluntary counselling and testing sites may be important for tuberculosis case finding and underscores the need to exclude tuberculosis carefully before starting IPT. In developing countries, further studies assessing the feasibility of IPT within tuberculosis and HIV/AIDS programme conditions are needed. Cost-effectiveness of IPT, compared with passive case finding, and its sustainability should be assessed before national policies are established.