Corona retest for all people in Chinese cities

Health authorities reported the first infection on Saturday, a 17-year-old female garment factory worker in Xinjiang's north-western region Kashgar.

Another 137 symptomless patients were found yesterday after the local government launched an emergency response to test all 4.75 million people in the entire region, the Daily Mail reported.

More than 2.84 million people in the Kashgar area had been tested as of Sunday afternoon with the rest expected to be completed by Tuesday.

Kashgar, a vast region in Xinjiang covering 162,000 square kilometres (62,549 square miles) of land, consists of one county-level city, Kashgar city, and 11 counties with 4.75 million residents.

Xinjiang last saw a resurgence of COVID-19 cases in July, one of the handful of flare-ups in China since its initial outbreak appeared to have been contained.

A total of over 890 cases were reported during the outbreak in Xinjiang's regional capital, Urumqi. No new cases had been found in the region since August 15.

But Xinjiang has been hit by a new wave of infections over the weekend after reporting the highest single-day increase of new symptomless infections in nearly seven month - since China began reporting daily counts of those cases on April 1.

The first patient, a 17-year-old woman, was found after being tested during a regular inspection and has been transferred to a hospital in the city, the Xinjiang health commission said.

She was said to have been discovered during routine weekly testing in Xinjiang for what state media called key groups of people. It did not specify who was in those groups or why she was among those tested.

Another 137 asymptomatic cases were found on Sunday during a drive to test 4.75 million people in the Kashgar area following the first reported infection.

It was not clear how the teenager was infected though, the official Xinhua news agency said. All of the new cases were linked to another garment factory where the patient's parents work. The parents had not tested positive for the virus, however, it said.

All close contacts of the Kashgar patient have been isolated for medical observation and local authorities are carrying out epidemiological investigations, the Xinjiang health commission said.

Many Kashgar-bound flights were cancelled on Saturday, according to travel platforms. Schools in the region have been closed and residents are not allowed to leave the city unless they have a negative test report.

Social media footage allegedly shows Kashgar residents lining up to receive COVID-19 tests while the city centre turned into a ghost town with empty streets.

A total of 20 new confirmed and 161 new asymptomatic cases were reported in the mainland on Sunday, the National Health Commission said in a statement.

The scale and speed of the testing is in line with efforts to stamp out other recent clusters of infection in China, including one in Qingdao city this month.

Earlier this month, the eastern Chinese port city of Qingdao reported 13 confirmed coronavirus infections, with most of the cases linked to a local hospital, prompting authorities to test nearly 11 million residents within four days to curb the virus spread.

The government said that the cause of the city's latest health crisis was traced to two infected patients who were responsible for unloading frozen seafood at the port.

Though the number of new cases is down sharply in mainland China from peaks in February, the government is wary of another wave of infections and maintains mass, rapid testing capabilities.

The virus emerged in the central city of Wuhan late last year. The total number of confirmed cases in mainland China stands at 85,810, while the death toll unchanged at 4,634.