Countries around the world are rushing to launch contact tracing apps to identify who an infected person has had contact with, as part of efforts to slow the spread of the coronavirus. 

The UK Government has announced the infrastructure was being put in place so that contact tracing could be rolled out on a large scale.

“As we look ahead, this is critical to keep the virus under control,” Matt Hancock, the Health Secretary, said on Thursday.

Mr Hancock said a new NHS contact tracing app was undergoing testing.

From teams of “corona detectives”, to Army cadets making thousands of calls a day, here are some of the ways countries are tracing the spread of Covid-19.

What is contact tracing?

Contact tracing is a method of preventing the spread of a disease. Health workers interview people who have been diagnosed with coronavirus and work out who they might have recently been in contact with. They put together a timeline and network of contacts, telling other people who might have been exposed to the infected person to quarantine themselves.

What are the UK’s plans?

The Health Secretary has revealed that infrastructure is being put in place so that contact tracing can be rolled out on a large scale. 

Ministers announced on Thursday that 18,000 contact tracers, including 3,000 health professionals, would be used to stem the spread of coronavirus by tracking anybody suspected of having Covid-19. 

But scientists have said the UK would need to recruit as many as 100,000 contact tracers for this to be effective.

A new NHS contact tracing app is currently undergoing testing. It works by using Bluetooth signals to detect when two phones come close to each other, and anyone who becomes unwell with coronavirus symptoms can notify the app, which would then inform other users with whom they had significant contact.

“The more people who sign up for this new app when it goes live, the better informed our response will be and the better we can therefore protect the NHS,” Mr Hancock said.

Germany 

In Europe, governments want to use Bluetooth ‘handshakes’ between devices as a way to measure the risk of infection, but approaches differ as to whether such contacts should be logged on devices or on a central server.

Under Germany’s contact tracing policy, every person who has come into contact with an infected patient in the last two weeks is tracked down and tested.

Although the number of national tracers is unknown, in one region, near the Dutch border, officials rang those isolating twice a day to check their symptoms and their temperatures, according to the Rheinische Post, a local newspaper.

Germany has also chosen a home-grown smartphone app, developed for the Robert Koch Institute, to trace infections.

The government told lawmakers it has backed the centralised platform developed by the Pan-European Privacy-Preserving Proximity Tracing (PEPP-PT) consortium and an app built by one of its members, the Fraunhofer Heinrich Hertz Institute.

The move puts it at odds with Apple, which has refused on privacy grounds to support the necessary short-range communication on iPhones.

Ireland

Irish public servants are making more than 2,000 calls a day to monitor and trace the spread of the coronavirus.

The contacts of every confirmed case in the country have been contacted, officials have said, and before lockdown this involved calling around 40 people per person.

Earlier this month, officials said 2,000 calls were being made a day from nine tracing centres across the country – this is set to be increased to 5,000 calls per day.

The team comprises 200 tracers, but 1,700 have received training in how to make the calls and could be utilised if the outbreak continues, The Irish Times reports.

Tracers include Defence Force Cadets and more than 60,000 personal contacts have been made so far.

Belgium

Belgium will hire 2,000 “corona detectives” to trace the contacts of individuals with Covid-19.

The team of tracers will be distributed regionally, with 200 in Brussels, 600 in Wallonia and 1,200 in Flanders, according to the national newspaper, De Tijd.

Those identified by the contact tracers will then be tested, if they test positive for Covid-19 they will be quarantined for two weeks.

Federal authorities are also working on developing an app to locate potential coronavirus infections. A legal framework is being designed for the app and regional authorities would choose which developer they wish to work with.

United States

The United States currently has 2,200 disease investigation specialists, known as contact tracers, according to a report by the Association of State and Territorial Health Officials (ASTHO).

But it would need at least an additional 100,000 to trace possible infections, ASTHO estimated.

Contact tracing is currently being conducted at a state level, despite Robert Redfield, head of the US Centers for Disease Control and Prevention, stating “it is going to be critical”.

Mike Bloomberg, the former mayor of New York City, will help build an “army” of coronavirus tracers to test, trace and then isolate residents with the virus in the tri-state area; New York, New Jersey and Connecticut. New York state currently has 500 tracers.

San Francisco has also launched a pilot program linking a tech company with 250 tracers, while Massachusetts has said it will hire around 1,000.

France

In France mobile teams will be used to trace the contacts of those infected with the coronavirus, French health authorities have said.

But they did not specify how many contact tracers the country currently has.

France aims to be able to test 700,000 people per week for the virus and begin lifting restrictions on May 11.

People infected with the virus will be put into quarantine at home or in specific facilities like hotels.

Later this month, lawmakers will vote on the government’s plan to launch a contact tracing app to fight the coronavirus outbreak. The planned smartphone app would warn users if they come into contact with anyone infected with the coronavirus.

South Korea

In South Korea, where daily new case totals have mostly been lower than the previous day since the end of February, authorities have rigorously traced an individual’s movements after testing positive.

They have done this through interviews, GPS phone tracking, credit-card records, and surveillance camera footage.

Once potential virus carriers are identified they are also tested.

Anonymised data showing Covid-19 patient’s movements is also published online, allowing others to identify if they may have come into contact with an infected individual.

The effective contact tracing system, known as the Covid-19 Smart Management System, is run by the country’s Centers for Disease Control and Prevention (KCDC) and can analyse a person’s movements in just 10 minutes.

Singapore

In Singapore, the government has said that it is able to trace between 2,000 and 4,000 contacts of Covid-19 patients each day, as members of the police and army phone people who may have come into contact with a confirmed case.

The country also launched the app TraceTogether on March 20 to track the contacts of those who have been infected with the coronavirus.

It claims to have around 1.1 million users, around one fifth of the country’s population, and uses Bluetooth technology.

The app logs unique codes over Bluetooth signals between nearby phones which have the app installed, the data is then used to identify contacts when one user tests positive for the virus.