Guizhou province is located in southwest China, where it is high incidence of TB and SF. COVID-19 swept the world in 2020, this prompted Guizhou to take a series of prevention and control measures, among which the most important measure was that people were required to wear masks in public places20,21, for example, on buses and subways, in hospitals and cinemas, in shopping malls and other gathering places, even people were advised to reduce their participation in crowd activities during the worst of COVID-19, and these public and gathering places were also disinfected more frequently than before22,23, the main purpose of these actions were to reduce the possibility that COVID-19 patients release pathogens into the air and healthy people inhale the pathogen.These prevention and control measures were implemented in Guizhou province until September 2021 with no new local COVID-19 patients24,25. We want to explore the impact of long-term COVID-19 prevention and control on other respiratory infectious diseases, so we chose TB and SF as the representative of chronic and acute respiratory infectious diseases respectively
In our study, we used exponential smoothing model to predict the number of TB and SF cases in Guizhou Province, and the parameters and test results of prediction model showed that our prediction model were successful.
Our study showed that the COVID-19 prevention and control measures also had a beneficial impact on TB and SF, so it is likely to have same effect on other respiratory infectious diseases, among which the most useful measure was wearing masks26,27, and our study results also showed that the impact on acute and chronic respiratory infectious diseases was different.
There was a rapid decline in both TB and SF cases in the first 1-2 months of COVID-19 prevention and control, because almost all of the focus at that time was on COVID-19, active detection of other infectious diseases such as TB and SF had been reduced or temporarily halted, as well as patient's willingness and behavior of taking initiative to see doctor and seek medical care had been affected. Another important reason for SF was that the COVID-19 prevention and control measures also reduced the spread of SF, meanwhile, as SF is an acute respiratory infectious disease, its incubation period is as short as 1-7 days28,29, which enabled us to see a decrease in the number of SF cases in a short time.
In addition, our research results showed that the decrease in the number of SF cases did not last for a long time in the context of COVID-19 prevention and control, it returned to the predicted state about 7 months later, which was probably related to gradual public's willingness decline to comply with normal prevention and control measures and the gradual psychological fatigue30. However, in addition to the decline in the first 1-2 months, TB began to decline significantly after the 11th month and the trend of decline lasted for 7 months or even longer, the main reason for this phenomenon may be that TB is a chronic respiratory infectious disease with a long incubation period, which can be 6 months to more than a year or more31,32, the COVID-19 prevention and control measures for did reduce spread of Mycobacterium tuberculosis and infection possibility in healthy people, but effect can only be seen after several months, and the effect will be very obvious when it occurs in an area where TB epidemic is very serious, like Guizhou province
Our study showed that the impact of the normalized COVID-19 prevention and control measures in Guizhou province on TB may be long-term, the number of TB cases may maintain a decline of 7 months or even longer after the implementation of these measures for 11 months, while the impact of these measures on SF may only be short-term, these measures can only sustain a decline in the number of SF cases for about six months.
Spatial aggregation analysis also showed that the normalized COVID-19 prevention and control measures were beneficial to reduce TB and SF cases, TB and SF cases in 88 Guizhou’s counties almost all showed reduced in different degree,especially in the areas with the largest number of cases. however, but they are still the most serious areas.