AT 8:30 a.m., a batch of  COVID-19 samples tested positive in a preliminary screening is sent to the Shenzhen Center for Disease Control and Prevention (CDC) for final confirmation, where lab technicians brace themselves for the verification work.

The Shenzhen CDC lab technicians have been carrying out the verification of suspected positive COVID-19 samples since the first COVID-19 case appeared in Shenzhen in January 2020, the Daily Sunshine reported yesterday.

“At present, this is the only laboratory that conducts lab confirmation for COVID-19 test results in the city,” Sun Ying, a doctor with the Pathogen Institute of the Shenzhen CDC, was quoted as saying.

According to Sun, suspected positive samples found in each district’s CDC, hospitals and third-party medical organizations in the city would be sent to the Shenzhen CDC for final confirmation. If the verification result is still positive, a final report will be issued.

In addition, the COVID samples awaiting further confirmation by the Shenzhen CDC also include those from the Shenzhen No. 3 People’s Hospital, which monitors the samples from hospitalized and discharged COVID-19 patients at any time.

“It can be said that we are exposed to positive samples every day,” said Sun. According to her, lab personnel in protective clothing would take over the boxes containing samples sent from medical institutions and then transfer the boxes to the lab for disinfection through a window.

After receiving the samples, the lab technicians must check the information of the samples first, then carry out pretreatment and nucleic acid extraction on the samples, amplify the specific region by quantitative fluorescence PCR and make the final confirmation according to the results.

“Since the first COVID-19 case occurred in Shenzhen in January last year, our lab has been operating 24/7,” said Sun, adding that there are currently more than 20 technicians engaged in nucleic acid tests in the lab. They take duty in turns, and each shift is up to 24 hours.

According to Sun, the time for sample verification differs as the number of samples sent to the lab varies. It usually takes more than four hours for the verification. But when the sample size is larger, the time required will even double.

“As the test result issued after lab confirmation is final, we need to make sure that there are no mistakes, so we are under a lot of pressure,” she said. Sun added that every front-line worker works really hard and sticks to their posts in the fight against the pandemic. However, it’s worth it to be able to contribute to the city’s COVID-19 prevention and control, she said. (Zhang Yu)