When the pandemic began, South Korea didn’t reach for an out-of-date version of Excel to keep on top.
Instead the country created a new, highly automated system called the Epidemiological Investigation Support System, or EISS, that pulls in credit card and smartphone data.
The software is used by investigators to track and trace contacts. It has been highly successful at identifying carriers and preventing deaths.
“This system enables us to stop the spread of the virus efficiently,” Kwon Dong-hyuk, director for risk assessment Korea disease control and prevention agency (KCDA) told Sky News.
He added: “Before we had the EISS it took an average of 24-48 hours to obtain and analyse the information on patients’ travel routes and credit card usage.
“But now with the system we are able to see the results from information analysis within an average of four to 12 hours.”
Mr Kwon said that for each positive case of COVID-19, they test more than 100 close contacts.
In the UK, statistics indicate that each positive case leads on average to fewer than three contacts being identified, and two contacts reached, according to data from 24-30 September.
South Korea has only a slightly smaller population than the UK – 51.64 million, compared to 66.65 million – but a much higher population density.
Despite facing multiple outbreaks of coronavirus, South Korea has recorded 24,805 cases and just 434 deaths, according to Johns Hopkins University.
When someone tests positive for COVID-19 in South Korea, their information is uploaded into the system.
Epidemic intelligence service officers interview the patient, trying to establish their travel history from two days before symptoms developed.
That’s combined with credit card and mobile phone data, which is crucial.
Mr Kwon said: “In the past, epidemiological investigation mostly depended on the information from the memories and words that a patient provides in a face-to-face or telephone interview.
“As a result, we often lost track of infection routes and contact.”
That data produces two types of contact, close and distant.
Close contacts are required by law to isolate for two weeks, either at home or at a quarantine facility.
A local health agency worker calls them twice a day, in the morning and afternoon, to check on whether they have developed symptoms.
If a COVID-19 patient has visited a “multiuse facility” such as a gym, church or bar, that location is closed and disinfected.
Locations are announced to nearby residents by text message and visitor logs for those locations are also investigated.
Last week, Sky News revealed that in the two weeks since its launch, only one alert had been sent from the NHS Test and Trace app about an outbreak in a venue – despite being used for millions of check-ins.
In South Korea, only close contacts are required to isolate; people who have only been in the vicinity of a COVID-19 patient are told to monitor themselves for signs or symptoms developing.
Stitching together all that data, often recorded in different formats, was a challenge. But the EISS was already up and running by 21 March.
Two things helped. First, the South Korean government had already introduced laws regarding the use of personal data in an epidemic following an outbreak of the MERS (Middle East Respiratory Syndrome) virus in 2015.
Second, the KDCA built on a previous project, a “smart city” platform developed by the government in 2018, to make more use of data in urban management and planning.
The South Korean national police also worked with the KCDA along with support from the credit finance association and telecommunication operators.
Human rights groups have criticised South Korea’s extensive data collection.
Mr Kwon insists all personal data is encrypted and stored securely. South Koreans are also notified when their personal information is being collected by the health authority.
“We will stop operation of the EISS when the pandemic finishes or when risk level is lowered to normal status,” he said.
“The data will be deleted completely from the system.”