Members of staff work at a COVID-19 testing lab. (Xinhua/Peng Ziyang)

Hangzhou in East China's Zhejiang Province has reported an asymptomatic COVID-19 case on Wednesday. The case, a 19-year-old man from Northwest China's Xinjiang Uygur Autonomous Region, has raised concerns over possible loopholes in detecting potential coronavirus carriers. 

The man departed from Kashi, transferred via Urumqi and arrived at Shanghai Hongqiao Airport on July 13. Two days later, he took the high-speed rail to Hangzhou, Wang Xuchu, deputy director of Hangzhou Health Commission, told a press conference on Wednesday. 

He went to the ophthalmology department at the Second Affiliated Hospital of the School of Medicine at Zhejiang University on August 4, where he tested positive in both the nucleic acid test and the IgM antibody test during a pre-surgery examination. No cough or fever symptoms have been observed so far, and the patient has been sent to a designated hospital for quarantine, according to Wang.

Xinjiang reported a confirmed local case in Urumqi on July 15, the first one to emerge after more than 140 days of no reported cases.  

Wang told the Wednesday press conference that the 19-year-old man wore a face mask the entire time during his visit to the hospital and on public transportation. Further tracing of his activities in Hangzhou are underway, and all close contacts have been put under medical observation.

Huang Jian, deputy director of the Second Affiliated Hospital of the School of Medicine at Zhejiang University, told the Wednesday press conference that all 463 medical staff at the ophthalmology department, which the confirmed patient went to, have received nucleic acid and IgM antibody tests. So far, all test results are negative. 

The eight medics identified as the patient's close contacts as well as their family members have been put into quarantine, and thorough disinfection has been applied to areas concerned, according to Huang.

Since the new wave of COVID-19 infections in Xinjiang from July 15, the regional government has issued measures concerning people entering and leaving Urumqi, including a 14-day quarantine and sweeping nucleic acid testing. 

As some COVID-19 cases have been discovered in some cities in China, including Dalian in Northeast China's Liaoning Province and Urumqi recently, the case in Hangzhou has raised public concerns on how to detect potential COVID-19 carriers to avoid more infections.  

Starting from July 17, all travelers departing from Urumqi must provide negative nucleic acid test results and health status statements, Air China told the Global Times on Wednesday. 

China Southern Airlines now requires both nucleic acid and IgM antibody test results, as well as health status statements and approvals from health departments at local districts for travelers departing from Urumqi, relevant personnel told the Global Times on Wednesday. 

Global Times