Covid: What is mass testing and how does it work?

Liverpool is undergoing a mass coronavirus testing program.

It now plans to expand to other parts of England and around the UK for students before returning home for Christmas.

How does mass testing work and what does it achieve?

Collective testing means telling everyone to test, whether they have symptoms or not.

The idea is to find healthy people who may be infected, but are not yet showing symptoms. They can then be isolated and prevented from spreading the virus.

Currently, in most of England, people can only be tested if they have the first symptoms. But during the Liverpool pilot, everyone living or working in the city is being offered a voluntary test.

Collective testing can be used in a more targeted way, including:

Mobile testing sites have been set up around Liverpool, in places like Kaver Homes, schools, universities and workplaces.

People can be invited to come for testing by their local authority, but they can also make their own online booking, or the whole family can get in their car.

Approximately 2,000 military personnel at 85 potential sites are assisting in the delivery of logistics and tests.

More than 23,000 people have been tested in Liverpool since the pilot began, with 154 people getting positive results. The population of the city is about half a million.

The plan will now be rolled out to 67 more areas, including parts of Nottinghamshire, Yorkshire, the North East and West Midlands in England, the North West and London.

Plans have also been made to ensure that university students in England and Wales can go home safely for Christmas. Plans for Scotland will be announced later on Wednesday.

NHS staff will also begin testing coronavirus twice a week. Regular testing of health workers is already done in the areas most affected by the virus.

The Liverpool Pilot offers two types of tests, in which the nose or throat is implanted – the PCR (polymerase chain reaction) test, and the side flow test.

PCR testing is considered the “gold standard” by epidemiologists, but it can take a day or more for results to be sent to a sample laboratory. However, it is the most widely used in the world.

The side flow test includes a handheld kit that gives results – a bit like a pregnancy test – in about 20 minutes, without the need for a lab. The fluid from the nasal swab or saliva goes to one end, then scars appear if you are positive.

Matthew Ashton, Liverpool’s director of public health, said the city has the capacity to conduct 50,000 side flow tests and 14,000 PCR tests a day.

Anyone who tests positive during the pilot should be self-isolated immediately for at least 10 days. Their contacts will be traced through NHS tests and traces.

Everyone else in their household should also self-isolate from the day the person became ill, or the day of the test, if they had no symptoms, for 14 days.

Self-isolation means staying at home and not leaving it to buy food, medicine or other essentials or even for exercise.

People should order groline groceries, or ask friends or family to help by getting the item they need and placing items outside the front door.

Anyone in England who fails to self-isolate after a positive test can be fined up to 10,000.

Anyone with a low income who was instructed to self-isolate in a phone call by NHS test and trace should try to claim a payment of £ 500 from their local authority.

In September, Mr Johnson outlined his “moonshot” plan to control the virus by mass testing, possibly by next spring.

He said that in the “near future” he wanted to start using the test to “treat people who test negative” more generally.

Other countries have already introduced mass testing programs.