Prevalence and Epidemiological Distribution of Mycobacterium tuberculosis and Rifampicin-Resistant Tuberculosis Among Patients Attending Selected Health Facilities in South-Western Nigeria

Abstract

Tuberculosis (TB) remains a major public health challenge in Nigeria, with emerging concerns regarding rifampicin-resistant tuberculosis (RR-TB). Geographic variations in Mycobacterium tuberculosis (MTB) prevalence and drug resistance patterns necessitate localised surveillance to inform evidence-based control strategies. This study aimed to determine the prevalence of MTB and rifampicin resistance among presumptive TB patients attending selected health facilities in south-western Nigeria, and to describe the epidemiological distribution across demographic variables. A cross-sectional, laboratory-based study was conducted among 324 presumptive TB patients recruited from health facilities in Osun, Oyo, and Lagos States. Sputum specimens were analysed using the Xpert MTB/RIF assay. Data were analysed using SPSS, with frequencies, percentages, and chi-square tests employed to examine associations between demographic variables and MTB detection. Statistical significance was set at p < 0.05. Overall MTB prevalence was 24.7% (80/324), with state-specific prevalence of 26.6% in Osun, 23.1% in Oyo, and 15.4% in Lagos. Among MTB-positive cases, 38.8% (31/80) exhibited rifampicin resistance. MTB-positive cases were equally distributed between males and females (50.0% each). The 20–29 and 30–39 years age groups accounted for 56.3% of MTB-positive cases. Artisans and traders together constituted 62.5% of MTB-positive participants. Among RR-TB cases, males represented 61.3%, and Osun State accounted for 67.7%. No statistically significant associations were observed between MTB detection and age (p = 0.081) or sex (p = 0.178). The findings indicate a substantial burden of MTB (24.7%) and an alarmingly high prevalence of rifampicin resistance (38.8%) in south-western Nigeria, exceeding global and several regional estimates. This study had several limitations.  The unequal state-specific sample sizes limited the precision of comparisons, particularly in Oyo and Lagos States. Second, the facility-based design limits generalisation to the wider population. Finally, the cross-sectional design limits causal interpretation of the findings. These data emphasise the urgent need for enhanced diagnostic capacity, strengthened drug-resistance surveillance, and targeted interventions to mitigate transmission and improve treatment outcomes.