Coronavirus: flights cancelled after cluster of cases at Chinese airport

More than 500 flights were cancelled at a major airport in eastern China on Wednesday after more than a dozen workers at the facility tested positive for Covid-19.

Health authorities in Nanjing, Jiangsu province, said routine testing detected the coronavirus in samples from nine cleaners at Nanjing Lukou International Airport, prompting tests on more staff.

In total, authorities found nine Covid-19 cases and five asymptomatic infections, while three positive samples were awaiting further diagnosis.

“The 17 patients are cleaners in the airport … who mainly work in the airport and on planes, so it is more likely that the infections are related to imported cases,” Nanjing Health Commission director Fang Zhongyou said, adding that health authorities were still tracing the source of the cluster.

Authorities said the city was preparing to launch mass testing for its 9 million residents. Swabs had been taken from 116,500 people living near the airport and 40 per cent of the tests had been processed, with none yet returning positive.

“When we mass test the city, we will need to coordinate with the vaccination programme,” Fang said.

“We still need to boost vaccination and build a higher immunity barrier to lay a more solid foundation for us to fight the outbreak.”

China has used mass testing, contact tracing, border control and vaccination to battle sporadic outbreaks of the coronavirus.

The country has administered more than 1.4 billion doses of Covid-19 vaccines, or around 102 doses per 100 people. It is not known how many people are fully vaccinated.

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Jin Dong-yan, a molecular virologist at the University of Hong Kong, said the Nanjing outbreak showed that China’s “border reopening effort has to be stepwise and more conservative”.

He said sequencing and epidemiological investigations could help identify the source and transmission route of the 17 infections, which were likely to have been caused by a superspreader.

“Was there a superspreader who infected all or most of them? Alternatively, did they have contact with the same fomite? The latter is probably less likely,” he said, referring to a material that can be contaminated.

He also suggested that testing could be done more frequently to identify cases faster.

Xu Yong, general manager of Eastern Airport Group, which manages the Nanjing airport, said all airport staff had to stay behind for tests while those already off duty have been asked to return to the airport immediately.

“Before test results come back, all departments will take the strictest measures and have all staff wear medical coveralls at work,” he said, adding that only some convenience stores in the terminals would stay open.

Deputy mayor Hu Wanjin said more than 20,000 residents in nearby higher risk areas had been asked to remain home.

Other city residents have also been asked to not leave Nanjing unless necessary. Those who travel via airport, railway and road are required to have proof of a negative Covid test result within the previous 48 hours.

Deputy director general of the Nanjing Centre for Disease Control and Prevention Ding Jie urged residents to get vaccinated.

“Vaccination is a safe and effective measure to prevent Covid-19 infection and transmission. For citizens who meet the conditions for getting vaccinated, please do so at a suitable time,” she said.