Nearly 18,000 workers were sealed into Shanghai’s main airport Sunday and tested for COVID-19 in one night after authorities detected seven cases linked to the cargo unit of the facility.

Social media lit up with dramatic smartphone videos showing large crowds of workers pushing against guards in white hazmat suits in the airport’s parking structure.

By Monday morning, local authorities grabbed hold of the situations, tweeting out videos of the 17,719 workers in orderly lines waiting to get tested, with calm piano music playing in the background. According to The Washington Post, it remained unclear what happened to the workers after that—if they were still being held at the airport, if they were moved to a quarantine facility, or if they were allowed to go home.

Local authorities reported that at least 11,544 have tested negative.

The lock-in and testing blitz was spurred after a seventh cases was identified and linked to the cargo unit. The first identified case was in a cargo worker who tested positive November 9 after checking into a hospital with fever, fatigue, and a nasal congestion. His co-worker tested positive the next day.

In the last three days—two weeks after those first two cases—five other cases have popped up. The five include a cargo screening handler, that worker’s wife, two other co-workers, and the wife of one of those co-workers.

According to the South China Post, one of the latest cases is an employee at the UPS international transit center at Pudong Airport.

Wear your mask

In a news conference Monday, local authorities said they believed the two initial cases became infected while they were cleaning a freight container from North America together, while not wearing masks, on October 30.

“The environment inside the container is humid, and that is conducive to the survival of the coronavirus,” Sun Xiaodong, deputy director of the Shanghai Centre for Disease Control and Prevention, said. Sun added that authorities had ruled out other transmission risks.

Since the testing scramble yesterday, hundreds of flights to the airport have been canceled.

Zhou Junlong, vice president of Shanghai Airport Group said that, moving forward, airport workers will have access to experimental vaccines that have been approved in China for emergency use.

https://arstechnica.com/?p=1725201