Jiangsu province's Yangzhou, a city hard hit in the latest COVID-19 outbreak in China, has made safer nucleic acid testing protocols available while receiving help from many other cities in battling the coronavirus.

Wang Jingsong, deputy director of Yangzhou's health commission, said infected patients can still be found outside the city's quarantined areas.

"Among the 25 new locally transmitted cases detected on Thursday, eight were found during mass testing in the city's downtown area and three went to hospital voluntarily after showing symptoms. This suggests that the quarantining of communities and villages still needs to be improved. Screening suspected patients and asymptomatic carriers in a timely manner will be crucial to the city's virus control work," Wang said.

During Yangzhou's seventh round of testing in the downtown area, which started on Thursday, residents were required to maintain a one-meter or two-meter social distance while being swabbed.

To avoid cross-infection at sample collection sites, Yangzhou has set up 812 collection sites and sent 5,726 health workers to swab samples at almost every residential community.

It only set up 481 collection sites for the fifth round of testing and 690 for the sixth in the downtown area, which has a population of more than 2 million.

"Some communities and villages shared collection sites in previous rounds of testing," said Lu Xueqin, a nurse who has participated in six rounds. "Now almost each community has its own collection site, and residents can have samples swabbed without leaving their community."

Lu added that specific plans have been made for swabbing samples, including residents going downstairs at different times to avoid group gatherings, and suspected cases along with contacts being quickly quarantined.

In addition to more detailed measures for nucleic acid testing, Yangzhou also received help from many other cities.

Due to Yangzhou's limited capacity to isolate possible cases, thousands of infected people's contacts and sub-contacts have been sent to nearby cities by bus, such as Huai'an, Zhenjiang and Nantong.

"We were welcomed by local residents," said Zhang Yang, who is now quarantined in Jiangyin, Wuxi. "The hotel is well equipped, and I smiled when I noticed the welcome gifts on the table."

She added that, "I received a bunch of flowers, disinfection supplies and a cute pink scented satchel with a pleasing fragrance of traditional Chinese medicine, and there's also a small fitness device which I haven't figured out how to use."

Guangzhou, Guangdong-based KingMed Diagnostics also helped Yangzhou establish China's largest inflatable laboratory to speed up testing for the coronavirus.

In the laboratory, 150,000 tests per day are carried out. To save time, 10 samples at a time are processed, with the result usually coming back negative. But if the result is positive, it means at least one of the 10 samples is positive, in which case the individual samples are retested to yield results for specific people.

Using this method, the lab can test as many as 1.5 million samples a day. Such labs have proved effective in containing the virus in other cities, including Nanjing, Guangzhou and Shijiazhuang.

As of Thursday, Yangzhou had registered 510 locally transmitted cases since July 20, with 27 patients in serious condition and 14 in critical condition being treated.

On Thursday, the Chinese mainland reported 14 new locally transmitted cases in Henan, four in Hubei, two in Hunan and one in Yunnan, the National Health Commission said on Friday.

cangwei@chinadaily.com.cn