Big data behind rapid response to Beijing market coronavirus cluster

  • Concerns raised about the use of surveillance technology in the fight against Covid-19 and how it will be used in future
  • Chinese social media users share their experiences of being contacted about the need to get tested because of the digital tools
  • Illustration: Henry Wong
  • “Have you taken the nucleic acid test?” has become a popular greeting in Beijing, where a Covid-19 outbreak linked to a 
    wholesale food market
     has been brought under rapid control through widespread testing.
    More than 3 million people – about 15 per cent of the Chinese capital’s population – have been tested for the disease since the first cases in the new outbreak emerged on June 11, according to the municipal government. Just eight days after the first infection was identified, 
    Beijing declared the transmission had been controlled

    “We will continue to see more infected people in the near future but the disease is under control,” Wu Zunyou, chief epidemiologist of the Chinese Centre for Disease Control and Prevention, said on June 18, while also paying tribute to the city’s response. “Beijing’s prompt handling and effective control made a remarkable contribution,” he said.

    As of Saturday, the number of patients in Beijing had climbed to 297, most of them related to the Xinfadi market in the city’s southwest district of Fengtai. But, while mass tracing and testing quickly brought the cluster under control, the role of “big data” has raised concerns, along with questions over whether the surveillance measures will be rescinded once the 
     has passed.
    The city urged people who worked at the sprawling market, and those who had visited it, since May 30, to get tested – as well as nearby residents and employees of restaurants, grocery stores, wholesale markets and food delivery companies.

    While many people were registered for testing by their employers or residential communities because of known links to the market, Fu Juan, 38, said she was spotted by big data. The process was quick but unnerving, she said, and began with a “suspicious” phone call from someone claiming to work for a disease control unit of the Beijing municipal government.


    “I was told that big data showed that I had been to Xinfadi recently, hence I should register with my neighbourhood to get a nucleic acid test as soon as possible. My first impression is that it must be a fraud. I’ve never shopped at Xinfadi,” she said.


    “Then my husband reminded me. I had picked him up somewhere 3km (1.8 miles) away from Xinfadi several days before. But I was in the car all the time.
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    Before she had an opportunity to check whether the call was genuine, community cadres had knocked on her door to obtain her identity information and persuaded her to get tested. The next day, it was arranged for her to attend a testing site at a stadium and, one day later, Fu received the result, which was negative.


    “The whole process was impressively fast,” Fu said. “When I was lining up for the test with thousands of people in the stadium, I was shocked by the capability, that China can identify so many people so quickly and get them tested.”


    In the neighbouring municipality of Tianjin, Wu Zhengyu, a 51-year-old teacher at a chess training centre, was also required last week to test for Covid-19 after returning from Beijing in early June. “I was in Beijing before the first case was reported. I probably passed by the Xinfadi area in the subway, but I’ve never been to the market,” Wu said.

    “However, I was told big data had spotted me and unless I was tested, my daughter could not go to school.” Wu said the test had cost him 200 yuan (US$28) and he was unable to continue teaching while under home quarantine. “I feel helpless. But who can I complain to? I was lectured by community cadres that all was for the sake of coronavirus control.”