A police officer inspects a CCTV surveillance system at an isolation camp in Guangzhou. Photo: Xinhua

The Chinese megacity of Guangzhou, which recently suppressed an outbreak of the highly contagious Delta variant, is codifying its anti-epidemic measures and experience for other cities to replicate if they become infected. 

The Guangzhou model hinges substantially on the role of police and their use of private information and big data for contact tracing, patient tracking and even interrogations.  

Guangzhou’s latest flare-up in May was triggered by the Delta strain from abroad, though exactly how it got through China’s seemingly impregnable border protection is still unknown. 

Details of two local infections released by Guangzhou’s Municipal Health Commission have underlined the variant’s speed of crossing from one person to another and thus its heightened threat.

One resident came down with Covid after queuing behind one asymptomatic carrier for less than a minute at a grocery store, while a diner caught the virus after sharing a washroom with an infected person for about 90 seconds. 

Preliminary data from Guangzhou’s Center for Disease Control (CDC) show some Delta cases could result in four generations of subsequent infections and that a typical incubation period can be as short as three days. 

Taxi drivers queue to receive nucleic acid testing in Guangzhou in China’s southern Guangdong province. The Delta variant has been found in the latest outbreak there. Photo: AFP

The Guangzhou-based Southern Weekly newspaper revealed that the city’s cadres had sought to map out places with likely infection chains to track down the close and secondary contacts of each of the city’s 153 known cases involving the Delta variant. 

Cognizant of Delta’s high contagion risks, Guangzhou authorities scrambled to deploy not only medical professionals but also police constables and even detectives that reportedly numbered in the tens of thousands. 

Contact tracing was largely conducted by police officers, according to Guangzhou’s papers, because they had access to the footage of almost all CCTV cameras throughout the city to identify and locate suspected carriers as well as their contacts and determine the perimeter of a locked-down area.

Police were also invited to apply their intelligence-gathering, forensics, manhunt and takedown tactics to help fight the virus. 

After police were given almost carte blanche powers, with CDC experts reportedly sidelined in Guangzhou’s mass mobilization to contain Delta between May and June, there were widespread allegations on WeChat and Weibo that patients and their contacts had been collared, rounded up and bundled into police cars and then taken to isolation facilities. 

As the police dragnet closed in on contacts of confirmed patients, police moved to impose stiffer penalties and repercussions like detention and criminal prosecution for anyone withholding or lying about their travel history when contacted by police. 

A police officer is seen with medical workers during an inspection of a locked-down factory in Guangzhou. Photo: Handout

Police access to big data technology and the databanks of surveillance and facial recognition systems at restaurants, public transport and even at residential estates and quarters across the city ensured swifter tracking and isolation. Previously, there was a much longer turnaround for CDC epidemiologists to apply to review footage and data.  

Mobile phone signal tracking was also widely used to monitor patients and contacts “still on the run” or anyone trying to abscond from treatment or isolation.

The Yangcheng Evening News reported that police tracked down three patients after gaining access to ride-hailing app Didi Chuxing’s data about trips made in Guangzhou during the resurgence. 

Miao Xing, a chief superintendent leading a crack police squad in Guangzhou’s Liwan district that was the hardest-hit area, told Xinhua that the force’s “sprawling knowledge” of technology and data analytics and processing prowess all came handy in combating the spread of the Delta variant in the megacity.

He said police sleuths and analyzers still had to trawl through massive amounts of video footage to pinpoint the places visited by a patient up to 14 days before he or she tested positive so that clear clues could be issued to frontline officers and medical personnel to find close contacts. 

“In most cases, we can, within hours, determine exactly when an infected person enters a restaurant or public venue and where he sits and who are those sitting on nearby tables and the time and duration the patient interacts with waiters and other diners, thanks to the ubiquitous CCTV penetration and our force’s big data analysis,” said Miao, hinting that the CDC and other health departments only played a supporting role.

“Without us, health personnel would need days or weeks to finish their similar investigations,” Miao said.  

The police superintendent said the total amount of footage and data examined in each case to identify contacts could exceed several dozen TB, or tens of thousands of gigabytes.

A Guangzhou police big data and centralized data processing center. Photo: Xinhua

Guangzhou’s CDC also noted on its WeChat account that police had fed vital data for its experts to determine the likely scale of clusters and size of lockdowns, so that patients and contacts could be whisked to wards and isolation facilities before they could mingle with more people. 

CDC staff also drew on police interrogation methods in their interviews of patients and their contacts, with an experienced police officer often present during such interviews. The presiding officer would sometimes intervene if an interviewee was perceived to be lying or giving misleading information.   

More police participation in the Covid response has, nonetheless, raised concern about privacy and data protection, as well as the treatment of patients and their contacts, in a country where police and other law enforcement agencies face few checks and balances.

Yet more Chinese cities are taking cues from the ways Guangzhou has managed to keep the Delta strain at bay. Xinhua reported that the National Health Commission and the Ministry of Public Security have set up a joint mechanism to pool recourses and manpower together to better respond to any future outbreaks in major cities. 

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