NANJING -- Nanjing, capital of east China's Jiangsu Province, has been on high alert after witnessing over 100 novel coronavirus infections since July 20.
The megacity with a population of more than 9.3 million has reported 173 locally transmitted COVID-19 cases including seven with severe symptoms as of Thursday, said local health authorities, noting that the virus strain behind the latest cluster infections was the highly infectious Delta variant.
On July 20, nine airport cleaners at the Nanjing Lukou International Airport were first found positive for the virus during a routine testing. New infections have now spread among residents of other occupations, including taxi drivers and university staff.
To stem the virus spread, the city launched the third round of an all-inclusive nucleic acid testing campaign on Wednesday.
Nearly 6,900 medical staff helped more than 1.9 million residents in Jiangning District, where the airport is located, complete their tests in just one day during a previous mass testing.
"We are always ready. I only slept three hours to help complete the testing," said Li Jie, a medical staff member in Nanjing. "We all believe that as long as everyone is united, we will soon get through this. I'm very optimistic."
Wang Meijuan, a 58-year-old Nanjing resident who lives about 20 km away from the airport, said that queuing up for nucleic acid testing was not a cozy experience under the scorching sun.
"But preventing the epidemic is now the priority," she added.
Thousands of community workers and volunteers have been mobilized to help maintain order during the mass testing.
"We used a school gymnasium to conduct the tests for our community with about 5,000 residents, as now it is the summer vacation. It was done very efficiently, a test took only about 10 seconds," said Tian Wen, a community worker.
Nanjing has also built advanced COVID-19 testing labs including six air-inflated labs, which can screen up to 1.8 million people every day, to enhance its nucleic acid testing capabilities.
In the wake of the resurgence of COVID-19 cases, authorities in Nanjing have intensified response, implementing measures such as mandatory negative nucleic acid test certificate for passengers leaving the city and closure of cinemas and gyms.
New infections were also reported among flight passengers who had visited the Nanjing airport and their contacts in other parts of China, including the provinces of Guangdong, Sichuan and Liaoning.
The Chinese capital Beijing also reported two locally transmitted COVID-19 confirmed cases as of Thursday noon, who had traveled to Zhangjiajie, a famous tourist city in Hunan Province where several tourists were diagnosed as confirmed or asymptomatic cases. Some of them reportedly came in contact with cases having travel history to the Nanjing airport.
"Those who have been inoculated can also get infected, but the number of infections could be much higher if they didn't receive vaccination," said Zhang Wenhong, a renowned medical expert in China. He added that the epidemic in Nanjing is a stress test for the country and, presses for more reflection concerning future epidemic prevention.
"Most virologists in the world agree that this is a virus with which we must learn to coexist. The epidemic in Nanjing further consolidated the claim that there will always be risks of infections in the future," Zhang said.
"We've won the fight against the virus, and we will surely find a winning formula in the future," he said.