Trends in rifampicin resistance among patients with presumptive TB in the pre-COVID and COVID-era.

Background: The COVID 19 pandemic has had its impact on tuberculosis notification, incidence, and management, particularly in the context of rifampicin-resistant TB. We set out to determine the trends in rifampicin resistant tuberculosis between the pre-COVID and COVID era in a resource-constrained setting.

Methods: This was a retrospective review of single early morning sputum from presumed tuberculosis between January 2016 and May 2022 in a regional TB referral and treatment centre in South-western, Nigeria. We used a molecular beacon to detect Mycobacterium tuberculosis (MTB) and mutations in the B gene using a real-time polymerase chain reaction (PCR).

Results: We analyzed 19,892 of 20,589 presumptive TB with complete data. Most subjects were in the age group 18-45 years (10,594; 53.3 %) and were males (11,492; 57.8 %). Of the 19,892 presumptive TB, 4,526 (22.8 %) were in pre-COVID-19 era (Jan 2016-December 2019) and 15,366 (77.2 %) cases were in COVID-19 era (Jan 2020-May 2022). The MTB notification declined during the COVID-19 era compared with the pre-COVID-19 era (10.5 % vs 12.9 %, p < 0.001). The annual prevalence of MTB rose from 5.6 % (2016) to a peak of 23.2 % in 2019 (pre-COVID-19 era), followed by a decline to 12.8 % in 2020 and 8.6 % in 2022 (COVID-19 era), p = <0.001). The overall incidence of RR-TB was 3.8 %. The incidence of RR was higher during pre-COVID-19 than the COVID-19 era, 9.5 % vs 2.5 %, p = <0.001. The incidence of RR-TB declined substantially from 28.0 % in 2016 to 1.6 % in 2021 but rose exponentially to 5.4 % in 2022. After controlling for confounders, only the pre-COVID-19 status was associated with increased odds for RR (adjusted odds ratio 3.3, 95 % confidence interval, 2.049, 5.421).

Conclusion: This study found a progressive decline in MTB notification since the COVID-19 pandemic's outbreak. Furthermore, RR-TB notification decreased gradually in the pre-COVID-19 era, with a resurgence in 2022. In the era of COVID-19, there is an urgent need to increase intervention efforts in order to halt the decline in MTB detection rates and the resurgence of RR-TB.