China has published new rules to intensify detection of asymptomatic novel coronavirus cases and standardize management procedures, aiming to curtail the risk of a resurgence of infections caused by people who are infected but show no symptoms.
Swift reporting of symptom-free cases and tracking of their close contacts, vigorous testing to screen out undetected cases and prolonged medical monitoring were highlighted in a circular released by the Joint Prevention and Control Mechanism of the State Council on April 8.
The document shows authorities' resolution to strictly manage asymptomatic cases and help assuage undue panic over stealth virus carriers, said Zeng Guang, chief epidemiologist with the Chinese Center for Disease Control and Prevention.
"The issue of asymptomatic patients has been existent since the beginning of the epidemic. But as the situation evolves, authorities have shifted epidemic control focus onto handling asymptomatic cases," Zeng told People's Daily.
Since China began publishing asymptomatic infections in its daily briefings on April 1, at least 17 provincial-level regions have reported such local infections while the proportion of cases imported from abroad is also growing, the National Health Commission said.
On April 9, the Chinese mainland added 47 new asymptomatic cases, with 1,097 cases under medical observation, including 349 found in travelers from overseas, the commission said on April 10.
Under the new regulation, all medical institutions should report newly identified asymptomatic cases within two hours of discovery. Investigation and registration of close contacts must be completed within 24 hours, with timely results submitted to the infectious disease reporting system.
Proactive testing of asymptomatic infections is to be expanded to cover all travelers from areas stricken with the virus. People either in organized epidemiological research or available for "opportunistic screening" will add to the conventional method of mainly testing close contacts of confirmed cases or those in clustered infections or likely exposed to the virus. Opportunistic screening means doctors can recommend people be tested based on experience even if they are not there for respiratory issues.
The new rules mandate all asymptomatic individuals and their close contacts be quarantined for 14 days and counted as confirmed if they show symptoms. Medical experts will also be called for timely diagnoses.
To qualify for discharge, isolated people must test negative twice. They are also subject to an additional 14-day medical observation at home and will be asked to visit hospitals for health checks in the second and fourth weeks after release. Support for extensive, targeted epidemiologic research will also be bolstered.
With the lifting of the lockdown in hard-hit Hubei province and resumption of work nationwide, Zeng said the likelihood of a fresh outbreak is very low but can't be ruled out.
"Our understanding of the virus is still insufficient, so more study is needed to determine whether asymptomatic infections will trigger a rebound of the virus and how long that might last," he said.
