Impact of short-course therapy on tuberculosis drug resistance in South-West Burkina Faso

Abstract

Setting: The Regional Tuberculosis Centre and the Muraz Centre in Bobo-Dioulasso, Burkina Faso. Objectives: To observe the trend of primary drug resistance in pulmonary tuberculosis patients 5 years into a short-course treatment programme and to assess the possible implementation of a further programme. Design: Bacteriological study of stains isolated from all newly diagnosed tuberculosis patients ( n = 300), all relapse cases ( n = 20) and all failure cases ( n = 58) from the Houet province, during the period from April 1992 to April 1994. Human immunodeficiency virus (HIV) serostatus was determined for the first 119 patients included in the study. Results:Mycobacterium tuberculosis was the predominant species as shown by 75.1% of the isolates; next was M. africanum, then atypical mycobacteria and finally M. bovis, representing 18.4%, 6.5% and 0.4% of the isolates respectively. Primary resistance (excluding atypical strains) was as follows: isoniazid 7.6%, ethambutol 1.0%, rifampicin 2.5%, and streptomycin 12.4%; 33.6% of the patients tested for HIV were HIV positive. There was no relationship between HIV serostatus and the identity of strains or drug resistance. However, negative acid-fast bacilli smear microscopy with positive culture was significantly more frequent in HIV-positive patients than in HIV-negative patients. Conclusion: This study shows a drop in primary resistance compared with previous studies carried out in Bobo-Dioulasso under the same conditions (setting, materials and methods, sampling procedures) in 1982 and 1986. This is consistent with the hypothesis that treatment monitoring and the introduction of short-course therapy in 1989 (2 HERZ/4 HR or 2 HRSZ/4 HR) have contributed to lower rates of primary drug resistance.