PREVALENCE OF MULTI-DRUG RESISTANT MYCOBACTERIUM TUBERCULOSIS (MDR-TB) IN KADUNA STATE, NIGERIA

Title: PREVALENCE OF MULTI-DRUG RESISTANT MYCOBACTERIUM TUBERCULOSIS (MDR-TB) IN KADUNA STATE, NIGERIA Authors: ALIYU, MUHAMMAD SANI Abstract: This study determined the prevalence of MDR-TB in Kaduna State, Nigeria using both phenotypic and genotypic methods. A total of 1186 sputum samples were screened for the presence of AFB by Ziehl-Neelsen staining procedure. Two hundred and twenty one (18.6%) of the samples screened were positive for AFB. Of the 221 smear positive sputum samples cultured on Lowenstein Jensen (L-J) medium, 171 (77%) yielded M. tuberculosis complex, 22 (10%) were AFB and culture positive but negative for MPT 64 antigen on SD-bioline, these were considered non tuberculous mycobacteria (NTM), 15 (7%) were smear positive but culture negative while 13 (6%) were contaminated. All the MTBC isolates (100%) were further characterized as M. tuberculosis genotypically by LPA. Tuberculosis and HIV co-infection was found in 21 (9.5%). One hundred and eighty two (82%) of the subjects were new cases while thirty nine (18%) were retreatment cases. Any drug resistance was found in 21 (52.5%) of all cases; 19 (47.5%) among new cases and 2 (5.0%) were found in retreatment cases. Mono-drug resistance against streptomycin was seen in 9 (22.5%) of the isolates tested. All mono-drug resistant isolates were from the new cases. MDR-TB was detected in 2 (5.0%) of the subjects all of which were found among new cases. Four (10.0%) isolates of all cases were poly-drug resistant, 3 (7.5%) were new cases, only 1 (2.5%) was retreatment case. One isolate each (2.5%) from new case and retreatment case showed poly-drug resistance to SM EMB, 1 (2.5%) was resistant to INH EMB. Poly resistance to SM INH EMB was found in only 1 (2.5%) new case. No poly-drug resistance to SM INH, RIF EMB, RIF SM or RIF SM EMB was observed. One isolate was characterized as MDR with bands at rpoβ MUT2A region and ihnA MUT2 corresponding to H526Y and A16G mutations respectively. Rifampicin mono resistance with band at rpoβ MUT3 corresponding to S531L was found in one isolate. Also, isoniazid mono viii resistance was observed in one isolate with ihnA MUT2 band corresponding to A16G mutation. The comparison of Geno Type MTBDRplus LPA and phenotypic LJ-proportion method showed that one isolate was mono resistant to RIF and one was mono resistant to INH by LPA, one and two MDR-TB isolates respectively were characterized by genotypic and phenotypic methods. The remaining isolates were found to be pan susceptible by both methods. There was association between TB and age (OR=1.72, CI=1.21-2.44, P= 0.002), sex (OR=2.10, CI=1.56-2.84, P