People wait for COVID-19 nucleic acid testing in Xiegang town, Dongguan, Guangdong province, on Monday, after a citywide testing campaign was launched. [Photo by Chen Fan/for China Daily]

Two locally transmitted COVID-19 cases detected in manufacturing hub

Authorities in Dongguan, a manufacturing hub in southern China's Guangdong province, launched citywide nucleic acid testing on Monday, shortly after two locally transmitted COVID-19 cases were reported.

A 19-year-old student surnamed Jia tested positive for COVID-19 on Sunday, following mass testing covering four city subdistricts－Nancheng, Dongcheng, Wanjiang and Guancheng－and Machong township between Friday and Saturday after the city reported a case on Friday.

The Dongguan campus of Guangzhou Xinhua University in Machong, where Jia studies, has been locked down, according to the local disease control and prevention center.

"The student was a close contact of the first confirmed patient in the city," said Zhang Qiaoli, deputy director of the Dongguan health commission.

The first confirmed patient, surnamed Li, was detected on Friday, the commission said.

The local disease control and prevention authority conducted a genomic sequencing test on the virus found in Jia on Monday morning and discovered a high degree of similarity with that found in Li, Zhang said.

"From the viewpoint of molecular biology, the source of virus infection of the student is from Li and her husband," she said.

Li's husband, surnamed Xiao, tested positive for COVID-19 early on Friday in the neighboring city of Shenzhen, according to the Shenzhen health authority.

Xiao visited Shenzhen airport on June 15, where a customs officer and a server were both infected with the Delta variant, a COVID-19 strain first found in India, after 38 passengers on a flight from South Africa to the city had earlier been confirmed to be infected with COVID-19.

Dongguan authorities conducted another round of nucleic acid testing in three townships－Humen, Chang'an and Dalingshan－on Saturday and Sunday, collecting more than 2.33 million samples, all of which tested negative for COVID-19.

The new round of citywide nucleic acid testing from Monday will cover 29 townships, subdistricts and industrial zones, excluding the townships of Humen, Chang'an, Dalingshan and Machong.

"The virus found in Li was identified by genome testing as a Delta variant but different from the one that led to the latest outbreak in Guangzhou," Zhang said.

On Saturday, Dongguan authorities announced that those leaving the city must show negative test results from tests taken within 48 hours of departure.

Guangzhou, Guangdong's provincial capital, reported no new cases of locally transmitted COVID-19 on Sunday, the second consecutive day of zero new confirmed cases.

As of Sunday, the city had reported 153 locally transmitted cases, including 146 confirmed patients and seven asymptomatic carriers, since a new outbreak began on May 21, according to Guangzhou's health commission.