Analysis of the characteristics of imported COVID-19 cases in mainland China.

ABSTRACT

Objective This study aimed to examine the epidemic characteristics of the COVID-19 imported cases entering mainland China from March 4, 2020 to October 31, 2021, so as to provide the reference for the prevention and control of imported epidemic at present. Methods Data were collected from the Daily Summary on the COVID-19 epidemic issued by the national/provincial health commission official website from March 4, 2020 to October 31, 2021, including " number of imported cases and existing imported cases and source country/territory and destination province for imported cases. Joinpoint regression was used to examine the time trends in the number of imported cases over time. Results From March 4, 2020 to November 3, 2021, the number of monthly newly imported cases and existing confirmed cases changed as a " W" shape. The imported cases came from 152 counties and territories in total, mainly from Myanmar, United States, Philippines and Russia (accounting for 27.6% of all imported cases). The number of imported cases mainly entered Shanghai, Guangdong, Yunnan, Sichuan, and Fujian, explaining 70.59% of total imported cases. Conclusions The great fluctuating change of imported cases in the mainland of China may be related to the change of global COVID-19 epidemic and domestic prevention and control policies. Considering the imbalanced distribution of source country/territory and destination province of imported cases, the government should take targeted measures in important source countries/terriories and destination provinces. Each province and municipality should modify its policy for preventing the imported epidemic dynamically according to the latest characteristic of source country/territory and virus mutation.Copyright © 2023, Publication Centre of Anhui Medical University. All rights reserved.