Prevalence of Multi-Drug Resistant Tuberculosis among Tuberculosis Patients Attending Chest Clinics in Osun-State, Nigeria

Background: The development of multidrug-resistant tuberculosis (MDR-TB) poses a considerable threat to tuberculosis control programmes in Nigeria. There is an increase in the prevalence of MDR-TB worldwide both among new tuberculosis cases as well as previously-treated ones. There is also a rise in transmission of resistant strains due to an increase in MDR-TB patients largely due to the poor drug compliance and the impact of Human immunodeficiency virus infection. Therefore, we intend to determine the extent of MDR-TB among attendees of chest clinics in Osun-State, Nigeria. Objectives: The objective of this study was to determine the prevalence of MDR-TB among confirmed tuberculosis patients attending chest clinics in Osun-State, Nigeria. Methods: This study was conducted among 207 attendees of chest clinics in Osun-State between June, 2015 and October 15, 2016. Sputum and blood samples of the participants were collected. GeneXpert test was carried out first on the samples for simultaneous identification of MTB and rifampicin resistance. Sputum samples were cultured on Lowenstein-Jensen (L-J) medium using N-acetyl-Lcysteine- sodium hydroxide (NALC-NaOH) decontamination method. Drug susceptibility testing (DST) to three first-line drugs was carried out using the proportion DST method. Results: The prevalence of MTB was found to be 27.5% while the prevalence of MDR-TB from the fifty-seven isolates was 10.5%. Previously treated and new cases had a prevalence of 7.0% and 3.5% MDR-TB, respectively. Seventy (33.8%) participants were positive for HIV infection, out of which twenty-six (12.6%) had co-infection of tuberculosis and HIV. The mono-resistance rates of the three first-line drugs used were: 5.3% and 8.7% for ethambutol (EMB) and isoniazid (INH), respectively. No isolate had mono-resistance (0%) to rifampicin (RIF). Conclusion: This study observed the prevalence of 27.5% MTB and a prevalence of 10.5% MDR-TB among the MTB isolates. The prevalence of TB is high in Osun State. MDR-TB prevalence is higher compared with the national estimate of MDR-TB (5.1%) of 2017. Resistant TB is a threat to national tuberculosis control and it is recommended that all the facilities be equipped to cater to its diagnosis.