Police in China’s Chengdu city use big data to trace potential contacts of Covid-19 cases
- People whose mobile phone signals are detected near the signal of a confirmed Covid-19 case receive text instructions to report to authorities
- The topical and intriguing term has been searched over 3 million times on Baidu
From last Wednesday, some Chengdu residents received telephone messages saying they had been identified by police as being in the “company of time and space” of confirmed Covid-19 cases. They were asked to report to the authorities and take at least two nucleic acid tests within three days to determine if they were infected with Covid-19.
According to Chengdu authorities, being in the “company of time and space” refers to people whose telephone signals were detected near – an area measuring 800 metres by 800 metres (2,600 feet by 2,600 feet) – a confirmed virus carrier for more than 10 minutes in a given 14-day period. In addition, at least one of the pair – the confirmed case or the person contacted by police – stayed in Chengdu for a total of more than 30 hours during that period.
By Wednesday, 82,000 such people had been identified in the capital city of Sichuan, which has a population of over 20 million.
Owners of the phones – regardless of whether there was direct contact with the case – are obliged to do the tests.