Étude de la résistance de Mycobacterium tuberculosis chez les patients bacillifères au Tchad

Abstract

Culture and resistance testing of Mycobacterium tuberculosis are not regularly performed in Chad. Sputa were obtained from three different categories of hospitals (district, regional and national) in Chad. All examined sputa were smear-positive and were investigated by culture and drug resistance testing for first-line antituberculosis drugs. From 232 sputa positive for acid-fast bacilli, 135 isolates of M. tuberculosis from different patients (46 women, 89 men, mean age 34 years) were analyzed. All the patients except one corresponded to new cases of tuberculosis. In total, 27 out of 135 isolates (20%) were resistant to at least one major antituberculosis drug. Resistance to isoniazid was the most frequent resistance observed, with 18 isolates (13%) presenting at least this resistance. Three isolates (2.2%) were resistant to isoniazid and rifampicin (multidrug resistance MDR) including one isolate being concomitantly resistant to streptomycin and ethambutol. The resistance rate differed in relation to the category of the hospital; the most important resistance rate was observed in regional hospitals (33%), while it was 16% and 14% in the national and district hospitals, respectively. HIV serology was performed in 81 patients, among whom 20 (25%) were positive. This is the first study that shows that drug resistance of M. tuberculosis is present in Chad. Besides single drug-resistant isolates, multidrug-resistant strains of M. tuberculosis could also be identified. This result highlights the urgency of initiating actions to detect drug resistance and limit the spread of drug-resistant strains.

Resistance Profile of Mycobacteria Isolated from Patients Undergoing Retreatment in Senegal

“…Among the anti-tuberculosis drugs tested in all types of patient, RMP presented the lowest resistance rates (43.66%) while the highest rate was noted with SM (56.06%) with an overall MDR rate of 43.66%. HIV status was not determined in patients as the analysis of the literature shows that the best factor associated with the rate of MDR-TB for a country is the failure rate to retreatment while the incidence of tuberculosis or co-infection with HIV in Africa do not appear to be significantly associated with multidrug resistance [7].…”

Emergence and clonal transmission of multi-drug-resistant tuberculosis among patients in Chad

“…The DOTS strategy has been implemented by the NTP, and the current TB therapeutic regimen used in Chad includes 2 months of quadri-therapy with rifampicin (R), isoniazid (H), pyrazinamide (Z) and ethambutol (E), followed by 6 months with isoniazid and ethambutol (2RHZE/6HE). For retreatment patients, treatment includes 2 months of rifampicin, isoniazid, ethambutol, pyrazinamide and streptomycin followed by 1 month of rifampicin, isoniazid, pyrazinamide and ethambutol and finally 5 months of rifampicin, isoniazid and ethambutol (2RHZES/1RHZE/5RHE) [ 8 ].…”

Genotypic Characterization of Mycobacterium Tuberculosis Strains Resistant to Rifampicin, Isoniazid and Second-Line Antibiotics in Chad

“…In Chad, a previous study on the drug resistance of tuberculosis in sputum in 232 new patients followed in three hospitals reported 58% (n=135) patients detected positive for tuberculosis, of whom 3 (2.2%) presented multidrug resistance to tuberculosis (MDR-TB). The rate of resistance to at least one anti-tuberculosis antibiotic was 20% [8]. Tuberculosis strains are resistant to at least two of the most potent anti-tuberculosis drugs: isoniazid and rifampicin [9,10].…”