[Resistance of mycobacterial tuberculosis complex to the main antibacillary agent in Yaounde, Cameroon]

To evaluate the current prevalence of initial and acquired resistance to the main antituberculosis drugs in Yaounde, isolates of M. tuberculosis complex obtained from sputum cultures of 602 adult patients with pulmonary tuberculosis (516 new cases and 86 old cases) consecutively admitted into the tuberculosis centre of Hôpital JAMOT from July 1994 to December 1995 were studied. The susceptibility of isolates to the major antituberculosis drugs was tested by the indirect proportion method. The overall resistance rate (1 or more drugs) was 35.2%, with initial resistance 31.8% (164 of 516) and acquired resistance 55.8% (48 of 86). Initial resistance to streptomycin was the most frequent (20.5%), followed by isoniazid 12.4%), thiacetazone (5.6%), rifampicine (0.8%) and ethambutol (0.4%). Initial resistance was noted as 25% to 1 drug, 5.8% to 2 drugs, 0.8% to 3 drugs and 0.2% to 4 drugs. Acquired resistance to isoniazid was the most frequent (45.3%), followed by streptomycin (40.7%), rifampicine (30.2%), thiacetazone (10.5%) and ethambutol (9.3%). Acquired resistance was found as 13.9% to one drug, 19.8% to 2 drugs, 12.8% to 3 drugs and 9.3% to 4 drugs. A combined resistance to rifampicine and isoniazid in the same patient was noted in 0.8% of the new cases and in 26.7% of the old cases. These high rates af antituberculosis drug resistance in Yaounde underline the urgent need to reestablish a tuberculosis control programme in Cameroon.