Trends and risk factors for drug-resistant tuberculosis in Nairobi County, Kenya: A comparative analysis before, during and after COVID-19

Background: Drug-resistant tuberculosis (DR-TB) is associated with a significant health burden and poses a major impediment to TB eradication. In Kenya, the COVID-19 pandemic disrupted healthcare services between March 2020 and February 2022. Consequently, the burden of DR-TB was projected to worsen. Despite these concerns, the impact of the pandemic on its trends remains unexplored. We conducted a quasi-experimental study to compare epidemiological trends of DR-TB before, during, and after the COVID-19 pandemic, and to identify associated risk factors in Nairobi County. Methodology: A quasi-experimental design utilising single-group interrupted time series (ITSA) was employed to assess the impact of COVID-19–related health system disruptions on DR-TB trends in Nairobi County. Laboratory-confirmed DR-TB data were retrieved from the TIBULIMS database and stratified by diagnosis period: pre-pandemic (March 2018–February 2020), intra-pandemic (March 2020–February 2022), and post-pandemic (March 2022– February 2024). Analyses were performed in STATA version 15. Results: A total of 616 DR-TB patient records were analysed. Overall, DR-TB cases rose slightly by 2.82%, from 213 pre-COVID-19 to 219 intra-COVID-19, and then declined significantly by 15.98% to 184 post-COVID-19 (p < 0.001). Cases were over twice as common among males. HIV infection was significantly associated with RR-TB (43.55%; n = 248, p < 0.0001) and monoresistant TB (21.02%; n = 214, p < 0.0001). ITSA showed significant COVID-19-related level changes in RR-TB, with an upsurge trend at the onset of the pandemic (+5.96 cases per quarter, p = 0.006), followed by a non-significant decline intra-pandemic, and a subsequent moderate increase post-pandemic (+2.56 cases per quarter, p = 0.022). Level changes observed in MDR-TB and MR-TB trends were not attributable to the pandemic (p = 0.094 and p = 0.0799, respectively). Conclusion: The study revealed fluctuations in MDR-TB, RR-TB, and MR-TB trends during the period. COVID-19-related health disruptions caused significant level changes in RR-TB trends. These findings highlight the importance of sustaining DR-TB diagnostic and treatment services to safeguard progress in TB control even during future public health crises.