Asymptomatic infections can spread viruses and cause infection, but with a low probability, a senior official of the National Health Commission said on Friday.

All levels of medical institutions should put asymptomatic infections in quarantine for 14 days, and directly report cases though an online system within two hours, according to Zeng Yixin, deputy head of the National Health Commission.

Asymptomatic infection refers to those who have tested positive via a nucleic acid test but do not show clinical symptoms, including fever or coughing.

Centers for disease control in county and district levels should investigate such asymptomatic infection cases within 24 hours of receiving the report, and at the same time register and isolate close contacts, he said.