Prevalence and genetic determinant of drug-resistant tuberculosis among patients completing intensive phase of treatment in a Tertiary Referral Center in Nigeria

Background: Drug-resistant tuberculosis (DR-TB) continues to be a challenge in developing countries with poor resources. Despite the high prevalence of primary DR-TB, its routine screening prior to the treatment is not performed in public hospitals in Nigeria. Data regarding drug resistance and its genetic determinant among follow-up patients with TB are lacking in Nigeria. Hence, the aim of this study was to determine the prevalence and genetic determinant of drug resistance among the follow-up patients with TB in a tertiary hospital in Nigeria. Materials and Methods: This was a cross-sectional, laboratory-based study conducted on 384 sputum samples collected from consented follow-up patients with TB. Standard microbiology methods (Ziehl–Neelsen staining and microscopy) and polymerase chain reaction (PCR; line probe assay [LIPA]) were used to analyze the collected samples. Pearson's Chi-square test was used to analyze the generated data. Results: Out of 384 sputum samples analyzed for Mycobacterium tuberculosis and DR-TB, 25 (6.5%) tested positive for acid-fast bacilli. These samples were subjected to PCR (LIPA), of which 18 (72%) tested positive for DR-TB. Of these 18 samples, mutations conferring resistance to rifampicin (rpoB) and isoniazid (katG and/or inhA) were detected in 12 (66.7%) and 6 (33.3%) samples, respectively. Transmission dynamics of DR-TB was not significantly (P > 0.05) dependent on demographic characteristics. Conclusion: There is a need to strengthen the laboratory capacity for the diagnosis of TB and drug resistance testing and make these services available, affordable, and accessible to the patients who need them