ABSTRACT
SETTING: Tuberculosis centre of Hôpital Jamot, Yaounde, Cameroon. OBJECTIVES: To determine the prevalence of acquired resistance (ADR) to the main anti-tuberculosis drugs, and to identify risk factors associated with its occurrence in Yaounde. DESIGN: A total of 111 previously treated adults admitted consecutively to the tuberculosis centre with sputum smear-positive pulmonary tuberculosis between June 1996 and July 1997 were included in the study. Information on potential risk factors for ADR was obtained from each patient, and human immunodeficiency virus (HIV) serostatus was determined. Drug susceptibility testing to the main anti-tuberculosis drugs was performed on cultures of Mycobacterium tuberculosis complex isolated from sputum samples of each patient by the indirect proportion method. All patients whose isolates tested resistant to at least one anti-tuberculosis drug were defined as having ADR. RESULTS: Growth of M. tuberculosis complex was obtained from sputum specimens of 98 (88.3%) of the 111 patients studied; 57 (58.2%) of these were resistant to at least one anti-tuberculosis drug. Resistance to isoniazid was the most common (54.1%), followed by resistance to rifampicin (27.6%), streptomycin (25.5%) and ethambutol (12.2%). Multidrug resistance was observed in 27 (27.6%) of the cases. In a multivariate logistic regression analysis, ADR was significantly associated only with monotherapy use in previous tuberculosis treatment(s) (P = 0.03). CONCLUSION: The rate of ADR of M. tuberculosis is quite high in Yaounde. Acquired resistance to rifampicin alone or in combination with isoniazid is also high. Monotherapy in previous anti-tuberculosis treatment(s) is a significant predictor of ADR in previously treated patients in Yaounde. These results underscore the urgent need for the re-establishment of a tuberculosis control programme, using the DOTS strategy, in Cameroon.