The Role of MTBDR plus ver 2.0 in the Detection of Drug Resistant Tuberculosis in Smear-Negative Pulmonary Tuberculosis in Kano, Nigeria

The development of multidrug resistant tuberculosis (MDR-TB) and extensively drug resistant  tuberculosis XDR-TB coupled with Human Immunodeficiency Virus Co-infection with TB has brought a major  setback in the tuberculosis control strategies worldwide including Nigeria. The Genotype MTBDR plus VER  2.0 is widely recognized for its excellent performance due to its rapid detection of drug resistant tuberculosis  especially from acid fast bacilli (AFB) smear-positive pulmonary TB cases which has brought much hope  towards reversing the spread of all forms of tuberculosis. The study aimed at evaluating Genotype MTBDR plus  VER 2.0 for detection of Drug Resistant-TB from sputum samples of smear-negative pulmonary TB cases. A  total of 175 smear-positive and 278 AFB smear-negative sputum samples were purposely selected from sputum  samples that were referred to North West Zonal Tuberculosis Reference laboratory. All the samples were  rifampicin resistant cases (confirmed by Genxpert) from their respective health centers across North-Western  Zone of Nigeria and were then subjected to Line Probe Assay (LPA) using Genotype MTBDR plusver 2.0. The  result shows that 87% of the AFB smear-positive samples were identified as positive for Mycobacterium  tuberculosis complex (MTBC) by the LPA and 13.7% were negative. Whereas 79%of the AFB smear-negative  samples were also detected as negative for MTBC by the LPA and 21% were positive for MTBC. The study  further revealed that 44.7% of the AFB smear-positive and 46.5% of AFB smear-negative samples were found  to be rifampicin resistant by LPA. Also 36.4% of AFB smear-positive and 34.5% of the AFB smear-negative  sample were found to be MDR-TB by the LPA. Most importantly, 15.1% of the smear-positive samples and  17.2% of AFB smear-negative samples were found to be susceptible to both rifampicin and isoniazid by the  LPA. The study demonstrated that the Genotype MTBDR plusVer 2.0 detects 87% of the positive smears and  79% of the negative smears as positive and negative for MTBC respectively. Most importantly, it detects 21%  of the AFB smear negative samples as positive for MTBC with some of them identified as rifampicin resistant  and MDR-TB respectively. This therefore reveals the excellent performance of Genotype MTBDRplusVer 2.0  in the diagnosis of DR-TB both in smear positive samples and smear-negative samples within a short turnaround  time.