The impact of COVID-19 national lockdowns on drug-resistant tuberculosis in KwaZulu-Natal, South Africa: A spatial analysis

Purpose: We sought to understand the impact of the initial COVID-19 mitigation strategies in 2020 on drugresistant (DR) TB diagnoses in KwaZulu-Natal province (KZN), South Africa. Methods: We compared the number, spatial distribution, and characteristics of DR TB diagnoses before and after the initial COVID-19 lockdown on March 26th, 2020. Information on DR TB diagnoses was collected from the CONTEXT prospective cohort study and municipality characteristics were collected from Statistics South Africa. We used Bayesian conditional autoregressive models and relative-risk surface maps to examine spatial correlates and patterns of DR TB notifications. Results: Between October 2018 and February 2022, there were 693 individuals diagnosed with DR TB in KZN, South Africa. The rate of diagnoses per year was 274 and 155 prior and after to the initial lockdowns, respectively, corresponding to a 43% decrease in the notification rate of cases. Compared to cases diagnosed before the lockdown, cases diagnosed after were less likely to have a fuel source for heating, piped water, a flush toilet, or own a phone (p-values <= 0.02). Changes in notifications were not homogenously distributed, with predominantly rural northeastern and southwestern municipalities having significantly greater relative-risks after the lockdown. Conclusions: We found a reduction in the rate of DR TB diagnoses after the COVID-19 pandemic lockdowns and observed that individuals diagnosed after the lockdowns had worse living conditions, fewer household resources, and more adults living in their household compared to before the pandemic.