HIV-associated tuberculosis in developing countries: clinical features, diagnosis, and treatment.

This article reviews the clinical aspects and diagnosis of HIV-associated tuberculosis in developing countries, and summarizes WHO's recommendations for treatment. According to WHO estimates (early 1992) over 4 million persons worldwide have been infected with HIV and tuberculosis; 95% of them are in the developing countries. Clinical features of HIV-associated pulmonary tuberculosis in adults are frequently atypical, particularly in the late stage of HIV infection, with non-cavitary disease, lower lobe infiltrates, hilar lymphadenopathy and pleural effusion. More typical post-primary tuberculosis with upper lobe infiltrates and cavitations is seen in the earlier stages of HIV infection. Extrapulmonary tuberculosis is reported more frequently, despite the difficulties in diagnosing it. WHO's recent guidelines recommend 6-month short-course chemotherapy with isoniazid, rifampicin, pyrazinamide and ethambutol for patients with HIV-associated tuberculosis. The older 12-month regimen without rifampicin is much less effective. Streptomycin should not be used, because of the risk of transmitting blood-borne pathogens through contaminated needles. Thioacetazone should be abandoned, because of severe adverse reactions observed among HIV-infected patients. The roles of preventive chemotherapy and BCG vaccination for prevention of tuberculosis are also briefly discussed.