[Impact of COVID-19 epidemic on syphilis case reporting in China].

ABSTRACT

Objective: To analyze the impact of COVID-19 epidemic on syphilis case reporting in China, and provide evidence to evaluate the epidemic situation of syphilis and strengthen the prevention and control of syphilis during COVID-19 epidemic. Methods: The data were collected from the National Notifiable Infectious Disease Reporting System of China Information System for Disease Control and Prevention, National STD Management Information System, and the "nCov2019" R package of github website. The changes of reported cases of syphilis before and during COVID-19 epidemic in China were analyzed. Joinpoint regression model was established by using the reported case number of syphilis from 2010 to 2018, the data in 2019 was used for validation, and the number of syphilis cases in 2020 and 2021 was predicted. The impact of COVID-19 epidemic on the number of syphilis cases was evaluated with calculating the percentage error (PE) between actual number and predicted number of syphilis cases reported.The correlation between reported cases of syphilis and COVID-19 was analyzed by Spearman's correlation analysis. The softwares of Joinpoint 4.9.1.0 and SPSS 18.0 were used for statistical analysis. Results: In 2020 and 2021, the reported cases of syphilis in China decreased significantly by 13.32% and 10.41%, respectively, compared with 2019 (before COVID-19 epidemic), and the reported cases of syphilis in 2021 increased by 3.36% compared with 2020. The reported cases of syphilis in 2020 and 2021 decreased by 17.95% and 20.41%, respectively, compared with predicted numbers. From January to March 2020, the reported monthly case number of syphilis was completely negatively correlated with the confirmed case number of COVID-19 (rs=-1.00, P<0.001). In the provinces with different scales of COVID-19 epidemic, there was also a negative correlation between the monthly reported case number of syphilis and confirmed case number of COVID-19 (all P<0.05). Conclusions: In China, the change of reported cases of syphilis was closely associated with COVID-19 epidemic in 2020 and 2021. Due to the influence of COVID-19 epidemic, the number of reported cases of syphilis decreased significantly, but it should not be thought that syphilis incidence will become a decline trend in the future. It is necessary to carefully and scientifically assess the changes in syphilis epidemic.