Prevalence of primary and acquired resistance of Mycobacterium tuberculosis to antituberculosis drugs in Benin after 12 years of short- course chemotherapy

SETTING: Benin National Tuberculosis Programme, West Africa. OBJECTIVE: To measure the prevalence of primary and acquired resistance of Mycobacterium tuberculosis to the antituberculosis drugs isoniazid, rifampicin, ethambutol and streptomycin in Benin from 1994-1995, after 12 years of short-course chemotherapy regimens. METHODS: Prospective study by cluster sampling according to the methodology recommended by the International Union Against Tuberculosis and Lung Disease (IUATLD) and the World Health Organization (WHO). RESULTS: The survey of primary resistance included 333 strains, of which 28 (8.4%) were drug-resistant, one to both rifampicin and isoniazid (multidrug-resistant). For acquired resistance, out of 57 strains tested 26 (45.6%) were resistant, six of which (11%) were multidrug-resistant. CONCLUSION: Despite the considerable increase in the number of tuberculosis cases observed in recent years (52% between 1987 and 1995), direct observation of patients taking their antituberculosis drugs during the intensive phase of treatment has limited the development of drug resistance in Benin.