BEIJING — Measures taken to manage asymptomatic coronavirus cases in China have proved to be effective, a health official said on April 15.

China has strengthened the detection, reporting and management of asymptomatic coronavirus carriers, He Qinghua, an official with the National Health Commission, said at a news conference.

Asymptomatic cases refer to people who tested positive for the coronavirus but develop no symptoms such as fever, cough and sore throat, yet they are infectious and pose a risk of spreading to others.

Medical institutions across the country are ordered to report the infection within two hours of an asymptomatic case being found, and a case epidemiological investigation should be completed within 24 hours, he said, stressing that China has taken asymptomatic coronavirus carriers as one of the key targets to be monitored since late January.

Asymptomatic carriers will be put under concentrated medical observation for 14 days and can only be released from quarantine upon two consecutive negative nucleic acid test results, followed by an additional 14 days of medical observation and follow-up visits, according to He.

Moreover, China has also intensified the screening of asymptomatic coronavirus cases, expanding to include close contacts of confirmed COVID-19 patients and asymptomatic individuals, and strengthened surveillance of key areas and people with a high risk of infection.

Since April 1, China has started to incorporate information of asymptomatic cases in its daily report and timely respond to social concerns through various means, while maintaining good communication with the World Health Organization.

Seroepidemiological investigations of asymptomatic cases have also been carried out in China to further understand the transmission characteristics, epidemiological characteristics and pathogenic path of the virus, so as to reduce the risk of contagion.

As of April 14, a total of 6,764 asymptomatic cases of novel coronavirus infection, including 588 imported ones, had been reported on the mainland.

A total of 1,297 asymptomatic cases, of which 251 were imported, had been re-categorized as confirmed cases, while 4,444 cases including 109 imported ones had been discharged from medical observation.