High rifampicin resistance found among tuberculosis cases in Benin City

A cross-sectional study at a referral hospital in Benin City, Nigeria, has detected Mycobacterium tuberculosis complex DNA in 8 percent of presumptive pulmonary tuberculosis patients, with rifampicin resistance identified in more than a third of those positive cases. The findings, published in BMC Infectious Diseases, underscore the persistent burden of tuberculosis in a country where the disease remains highly prevalent and is frequently linked with HIV infection.

Researchers enrolled 300 presumptive pulmonary tuberculosis patients attending Central Hospital, Benin. Each participant completed a structured questionnaire covering sociodemographic profile, symptoms, lifestyle and environmental characteristics. Sputum samples were then analysed for M. tuberculosis complex DNA and rifampicin resistance using the standard GeneXpert MTB/RIF assay, a molecular diagnostic platform manufactured by Cepheid that detects the bacillus and rifampicin resistance in a single test. Blood samples were screened for HIV infection using immunochromatographic test kits.

The molecular assay returned positive results for M. tuberculosis complex DNA in 24 of the 300 participants, corresponding to a prevalence of 8.0 percent, with a 95 percent confidence interval of 5.2 to 11.7 percent. Among these 24 MTBC-positive individuals, rifampicin resistance was detected in 9 cases, or 37.5 percent, with a wide confidence interval of 18.8 to 59.4 percent reflecting the small number of positive samples. The authors describe this level of resistance as notably high, a significant challenge for tuberculosis therapy, prevention and control in the region.

Age emerged as a strong correlate of infection. Individuals aged 34 to 49 years and those aged 50 to 65 years exhibited approximately four-fold higher odds of tuberculosis compared with participants aged 18 to 33 years, a difference that reached statistical significance at p = 0.035. Residence was also associated with MTBC DNA detection, with the study reporting a significant relationship at p = 0.024, and the authors note that urban or suburban residence was among the factors significantly linked to a positive result.

Bivariate analysis identified several clinical factors associated with tuberculosis. HIV infection carried a crude odds ratio of 4.82, with p = 0.024, meaning HIV-positive participants had nearly five times the odds of a positive MTBC result. Persistent cough showed the strongest association, with a crude odds ratio of 5.73 and p < 0.001. Hemoptysis was associated with an odds ratio of 4.05 at p = 0.013, and a history of previous tuberculosis carried an odds ratio of 5.93 at p = 0.014.

Notably, the study found no significant associations between tuberculosis and the assessed behavioural or environmental factors, suggesting that in this population the clinical and demographic variables carried the strongest signals. The combination of older age, HIV infection, urban or suburban residence, persistent cough and history of TB together characterised the profile of patients in whom MTBC DNA was most likely to be detected among those presenting with presumptive disease.

The findings carry practical implications for tuberculosis control in Nigeria, where rifampicin resistance complicates treatment decisions. The high proportion of resistance among detected cases at this referral centre indicates that drug resistance is a substantial component of the tuberculosis seen in this setting, and the authors state in their conclusion that increasing resistance to rifampicin presents a significant challenge for TB therapy, prevention and control. The study’s reliance on the GeneXpert MTB/RIF assay reflects the use of molecular diagnostics for simultaneous detection of the bacillus and resistance to this drug.

The authors caution that the study was conducted among presumptive tuberculosis patients at a single referral centre, so the 8 percent prevalence reflects the proportion of people already suspected of having the disease who tested positive, not the prevalence in the general population. As a cross-sectional design, the study captures associations at a single point in time and cannot establish causal relationships between the identified factors and infection. The wide confidence interval around the rifampicin resistance estimate also reflects the limited number of positive samples. Nevertheless, the study provides a detailed snapshot of the molecular epidemiology of tuberculosis and drug resistance among patients seeking care at a Nigerian referral hospital, and highlights the continued intersection of HIV and tuberculosis in the region.

Subject of Research: Molecular detection of Mycobacterium tuberculosis complex DNA and rifampicin resistance among HIV-positive and HIV-negative presumptive tuberculosis patients attending a referral centre in Benin City, Nigeria

Article Title: Molecular detection of Mycobacterium tuberculosis complex DNA and rifampicin resistance among HIV-positive and HIV-negative presumptive tuberculosis patients attending a referral centre in Benin City, Nigeria

Article References: Okundaye, M. I., Omoruyi, Z., Ekhator, E., Aichienede, J. E., & Emonbeifo, F. O. (2026). Molecular detection of Mycobacterium tuberculosis complex DNA and rifampicin resistance among HIV-positive and HIV-negative presumptive tuberculosis patients attending a referral centre in Benin City, Nigeria. BMC Infectious Diseases. https://doi.org/10.1186/s12879-026-14700-w

Image Credits: AI Generated

DOI: 10.1186/s12879-026-14700-w

Keywords: Molecular, detection, Mycobacterium, tuberculosis, complex, rifampicin, resistance, HIV-positive, HIV-negative, presumptive, patients, attending