Incidence, severity and treatment outcome of tuberculosis in the era of the COVID-19 pandemic, France, 2018-2023.

Introduction: In France, the average steady decline in tuberculosis (TB) incidence close to 5 % per year over the past half-century has been occasionally interrupted by disruptions related to external events. We describe the impact of the COVID-19 pandemic on TB incidence, severity and treatment outcome.

Methods: We analysed the number of TB cases and treatment outcomes reported through the mandatory notification system through 2018-2023. We compared cases reported, notification rates and percentage of cases completing treatment before and after the occurrence of the COVID-19 pandemic.

Results: The TB rate and the mean weekly number of cases decreased from 7.6/100,000 to 6.8/100,000 (-10 %) (p=0.96) between 2019 and 2020. This decreasing trend continued, albeit more moderately, in 2021 (-7 %) and 2022 (-2 %). The trend shifted upward in 2023 (7.1/100,000, +15 % compared to 2022). The mean weekly number of reported cases significantly decreased between 2018 (n=97), 2019 (n=97) and 2020 (n= 88) (p<0.01) and significantly increased between 2022 (n=77) and 2023 (n=91) (p<0.01). There was no increase in the number of severe cases, multidrugresistant (MDR) cases or deaths in the years following the pandemic. The proportion of persons that completed treatment was 83.3 % for cases notified in 2022, a significant increase compared to the 79.7 % estimated for 2019 cases (p<0.01). However, less than half of the reported cases had information on treatment outcome.

Conclusion: The important fall in TB incidence in France in 2020 is likely explained among other factors by the social and health measures that were implemented soon after the onset of the COVID-19 pandemic. In 2023, the situation had reversed although no impact on severe and MDR cases and deaths was observed.