Trends of SARS-CoV-2 Infection in Rural Area in Sentinel Community-Based Surveillance - China, December 2022 to January 2023.

ABSTRACT

Introduction: In late 2022, a rapid transmission of Omicron variants of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) occurred throughout China. The purpose of this study was to provide the latest data and evaluate trends of SARS-CoV-2 infection in rural China among the community population. Methods: Data on SARS-CoV-2 infection among approximately 90,000 participants in rural China were collected by the National Sentinel Community-Based Surveillance (NSCS) system. Participants were tested for SARS-CoV-2 infection (defined as positive for SARS-CoV-2 nucleic acid or antigen) twice weekly from December 16, 2022 to January 12, 2023. The daily average of newly positive rate and its estimated daily percentage change were calculated to describe the national and regional trends of SARS-CoV-2 infection in rural China. Results: In rural China, the daily average new positive rate of SARS-CoV-2 infection peaked at 4.79% between December 20-22, 2022 and then decreased to 0.57% between January 10-12, 2023, with an average decrease of 29.95% per round. The peak of new SARS-CoV-2 infection was slightly earlier and lower in North China (5.28% between December 20-22, 2022) than in South China (5.63% between December 23-26, 2022), and then converged from December 30, 2022 to January 2, 2023. The peak of 6.09% occurred between December 20-22, 2022 in eastern China, while the peak of 5.99% occurred later, between December 27-29, 2022, in central China. Conclusions: Overall, the epidemic wave in rural China peaked between December 20-22, 2022, and passed quickly following the optimization of prevention and control measures. Currently, SARS-CoV-2 infection in community populations in rural China is sporadic.