Limited effect of reducing pulmonary tuberculosis incidence amid mandatory facial masking for COVID-19

Tuberculosis (TB) remains a significant health and public issue in many countries. Its incidence and mortality have been decreasing in many countries. The recent COVID-19 could have significant impacts on the transmission and health care for this chronic disease by obligatory facial masking and by affecting healthcare capacities. We asked whether the trend of TB incidence and mortality would be affected by COVID-19 epidemic due to their common air transmission route. We also asked whether the incidence of TB in regions with different COVID-19 incidence would be similar. We obtained the annular new cases of TB and multi-drug resistant TB through Taiwan CDC and estimated the incidence and mortality by the population numbers in 7 administrative regions in Taiwan in 2011-2021. The result showed that incidences of TB and multi-drug resistant TB in recent 10 years show a continuously decreasing trend, even amid the COVID-19 epidemic in 2020-21. In addition, the mortality of TB shows similar decreasing trend in 2020-21. From 2011-2011, the highest incidence of TB was in the southern and eastern Taiwan whereas the lowest incidence of TB was in northern Taiwan. In contrast, the highest incidence of COVID-19 in 2020-21 was in the northern Taiwan while the lowest incidence of COVID-19 in 2020-21 is in the southern and eastern Taiwan. These results indicated that in the low COVID-19 incidence regions of Taiwan, the incidence of TB remained high during COVID-19 pandemic. We concluded that the decreasing trend of incidence and mortality of TB does not change during COVID-19 epidemic in Taiwan. The mask wearing and social distancing could prevent the transmission of COVID-19, however, their effect on the limiting spread of TB may be limited.