A cured patient waves goodbye to staff members at the Changjiangxincheng medical observation station in Wuhan, central China's Hubei Province, April 13, 2020. Photo: Xinhua

 
Wuhan in Central China's Hubei Province on Tuesday launched a three-day random sampling survey for residents to probe their antibody level and study the occurrence of asymptomatic infection and improve epidemic control measures.

According to the local newspaper Hubei Daily on Tuesday, a total of 11,000 residents will be randomly selected for the sampling survey. They will come from 100 communities in 13 districts of the city. 

The survey will be expanded to 10 provinces and cities to study the occurrence of asymptomatic infection, better understand the public's antibody level, and to provide a scientific basis for adjustment of epidemic prevention and control measures, said Ding Gangqiang, an official with the Chinese Center for Disease Control and Prevention (CDC), who is currently stationed in Wuhan.

"At present, the transmission characteristics, epidemiological characteristics, and pathogenic laws of the new coronavirus still need to be further understood, and the epidemic prevention and control strategies need to be continuously improved," Ding said.

According to the report, to ensure the data's accuracy and authenticity, the survey will strictly follow the principle of random sampling. 

The respondents should be residents who have stayed in the local community for at least 14 days between January and March.  

Epidemic control-related personnel including grassroots officials, police officers, and taxi drivers will be included in the survey.

The survey includes a blood test for the IgG/IgM antibody, and the collection of upper respiratory tract specimens for nucleic acid testing. 

According to the report, the tests will be free of charge.  

A resident in the Jiangxia district of Wuhan surnamed Yu who had the test on Tuesday told the media he felt more secure after taking the test.

On Tuesday morning, 880 community residents in the Jiangxia district as well as 80 working personnel in the area participated in the survey.