Article 1 This Protocol is formulated in accordance with the Law of the People's Republic of China on the Prevention and Control of Infectious Diseases and the Law of the People's Republic of China on Frontier Health and Quarantine in order to strengthen the detection, reporting, and management of asymptomatic persons infected with COVID-19 virus.
Article 2 The asymptomatic persons infected with COVID-19 virus (hereafter referred to as asymptomatic persons) refers to those who have no relevant clinical manifestations including clinically detectable signs or self-perceived symptoms such as fever, cough, or sore throat, but who have tested positive for COVID-19 virus in respiratory specimens or other specimens. There are two types of asymptomatic persons: 1) those who have no self-perceived symptoms or clinically detectable signs throughout the 14-day quarantine; and 2) those who are "asymptomatic" during the incubation period.
Article 3 Asymptomatic persons are contagious with risks of transmission.
Article 4 Strengthen the monitoring and detection of asymptomatic persons by: 1) actively testing close contacts of COVID-19 cases during their medical observation period; 2) actively testing during cluster investigations; 3) actively testing people with exposure during tracing the infection source; 4) actively testing people with travel or residential history in areas abroad with sustained COVID-19 transmission; and 5) detecting during epidemiological investigation and opportunistic screening.
Article 5 Standardize reporting of asymptomatic persons. Healthcare facilities of all types and at all levels, having detected asymptomatic persons, should report the case within 2 hours through direct online reporting. After receiving the report of asymptomatic persons, the county-level CDC should complete the case investigation within 24 hours, promptly register close contacts, and submit the case questionnaire form or investigation report through National Notifiable Infectious Diseases Reporting System in a timely manner. After the asymptomatic infected person is lifted from the centralized medical observation, the healthcare facility should fill in the completion date of medical observation in National Notifiable Infectious Diseases Reporting System in a timely manner.
Article 6 Strengthen information transparency. The national health authority of the State Council shall publicize the information of reporting, outcome, and management of asymptomatic persons on a daily basis. The provincial authority shall publish the relevant information about their own jurisdiction. Local transmission and importation of COVID-19 cases shall be calculated and reported separately.
Article 7 Strengthen the management of asymptomatic infected persons. Asymptomatic infected persons should be placed under medical observation for 14 days. During this period, those who develop clinical symptoms and signs of COVID-19 should be reclassified as confirmed cases. Those who have negative nucleic acid test results twice consecutively during the 14-day centralized medical observation (at least 24 hours apart between sampling) can be lifted from medical observation; those who have no clinical symptoms but have still tested positive during the medical observation period should continue to be under centralized medical observation.
Article 8 If asymptomatic persons manifest clinical symptoms during the period of centralized medical observation, they should be immediately transferred to a designated health care facility for standard treatment and reclassified in a timely manner after the diagnosis has been confirmed.
Article 9 Close contacts of asymptomatic infected persons should be put under 14-day centralized medical observation.
Article 10 An expert panel should be organized to provide consultation tours for asymptomatic persons under concentrated medical observation to promptly detect potential confirmed cases.
Article 11 Asymptomatic persons who have been lifted from centralized medical observation should be placed under another 14-day medical observation and follow-up, and they should have a follow up visit to the designated hospital for health check up in the second and fourth week after the lifting of centralized medical observation.
Article 12 Targeted screening efforts should be scaled up by testing close contacts of detected cases and asymptomatic persons. Enhance surveillance in key areas and settings and among key population groups. Identified asymptomatic persons should be put under centralized medical observation.
Article 13 Asymptomatic infected persons have the characteristics of silent transmission, subjective symptoms, and limitations in being detected. The national government supports scientific research on infectivity, transmission, and epidemiology of asymptomatic infected persons.
Article 14 Strengthen information communication, exchange and cooperation with relevant countries and international organizations such as the World Health Organization, and revise the diagnosis and treatment protocol and prevention and control protocol as required.
Article 15 Public education and communication on COVID-19 should be enhanced in all localities to provide evidence-based guidance on protection for the public; and extensive training should be conduct to improve the capacity of grassroots health care workers and community workers in prevention and control.
Acknowledgement: China CDC Weekly would like to thank Xijuan Fu of the WHO China Office and Liping Wang of China CDC for their contributions in translating and editing this document (1).