National trends in the prevalence of tuberculosis before and during the COVID-19 pandemic, 1998-2021: a nationwide representative study in South Korea

Objective: In this study, we investigate changes in the prevalence of tuberculosis (TB) before and during the COVID-19 pandemic in South Korea, analyzing the effects of age, socioeconomic, and environmental variables on TB trends over a period of 24 years. Investigation into the association between TB and the COVID-19 pandemic can accelerate advances in the prevention and treatment of both diseases. Methods: This study utilized data from the Korea National Health and Nutrition Examination Survey conducted between 1998 and 2021 by the Korea Disease Control and Prevention Agency. The study population included individuals aged ≥ 5 years, selected to represent a broad spectrum of the South Korean adult population (n=186,561). The data collected encompassed a range of variables, including age, sex, residence, body mass index, education level, income, and other health-related factors potentially influencing TB trends. Results: A total of 186,561 surveys were included in this study. There was an increase in the trend of TB prevalence before the pandemic (trend in β, 0.124 [95% CI, 0.047-0.201]), which was not apparent during the pandemic. Females saw a significant positive trend in TB prevalence before the pandemic (trend in β, 0.146 [0.055-0.238]), which decreased during the pandemic. Similarly, individuals living in both urban and rural regions (trends in β, 0.104 [0.018-0.189] and 0.239 [0.059-0.420], respectively), those with a high school diploma, middle school, or elementary school education (0.185 [0.056-0.314], 0.239 [0.059-0.420], and 0.740 [0.541-0.939], respectively), and those in the second and lowest income quartiles (0.282 [0.087-0.476] and 0.195 [0.037-0.353], respectively) all showed significant positive trends in TB prevalence before the pandemic, which were no longer apparent after the onset of the pandemic. Conclusions: There was a sharp decrease in TB prevalence between 2020 and 2021. Differences previously seen between males and females, and those of differing income and education statuses were nullified during and after the pandemic. This highlights the importance of healthcare utilization, timely diagnosis, and effective treatments for diseases that are a significant public health risk.