Epidemiological Characteristics and Associated Factors of Imported Respiratory Infectious Diseases in China, 2014 - 2018

Background With the progress of globalization, the international mobility of population is increasing, which facilitates the cross-border transmission of respiratory infectious diseases (RIDs). The aim of this study is to analyze the epidemiological characteristics and relative factors of imported RIDs for using high-tech and wisdom methods to early find and stop the important RIDs spread to China. Methods The imported RIDs cases from 2014 to 2018 enrolled in this study were screened by the inbound sentinel network of customs and national notifiable disease reporting system in China. The spatial, temporal and population distribution of imported respiratory infectious diseases were analyzed. Seasonal index was calculated to describe the seasonality, and Pearson correlation coefficients were assessed to examine associations between independent variables and imported cases. Data analysis and visualization were carried out with R (version 4.0.5). Results Among 1,409,265,253 inbound travelers, 31,302 (2.22/100,000) imported RIDs cases from 143 countries within 5 continents were reported. The incidence of imported RIDs in 2018 (2.77/100,000) was nearly 5 times that of 2014 (0.56/100,000). Among foreigners, the incidences were higher in male (5.11/100,000), 0–14 year old group (14.06/100,000), and Oceania (10.98/100,000). Influenza accounted for the majority of imported RIDs(90.64%), with obvious seasonality. The spatial distribution of imported RIDs was different between Chinese citizens and foreigners. With the increase of inbound travel volume and the number of influenza cases in source countries, the number of imported RIDs cases increased. Conclusions Our study showed RIDs imported into China from 143 countries around the world. Therefore, it has great potential risks of transmitting important RIDs to China. So, it is urgent to strengthen the surveillance at customs for inbound population, and establish the wisdom surveillance and warning systems for preventing and stop imported RIDs spreading to China.