“Surge” tests are being delivered to homes across England after more cases of the South African coronavirus variant have been discovered.

The variant in question – also known as 501Y.V2 – was first detected in two people who arrived in the UK from South Africa in December 2020. However, new cases have now been identified in people who haven’t travelled to the country, suggesting this variant could be spreading in the community.

As such, some 80,000 over-16s in England are to receive door-to-door Covid tests – or “surge” testing, as it’s been called – in an attempt to identify both asymptomatic and symptomatic cases and reduce transmission of the new variant.

The South African variant is thought to be far more transmissible, but not more lethal, than other variants of the coronavirus. There’s also emerging evidence to suggest it is less susceptible to immunity induced by the Covid-19 vaccines. 

This is why health authorities are keen to get as many people tested as quickly as possible. Here’s what you need to know about the new surge testing plans – including what to do if one lands on your doormat.

Who will be ‘surge’ tested for Covid?

People aged 16 and over in eight different areas – Ealing, Tottenham and Mitcham in London (postcodes W7, N17, CR4); in Walsall (WS2); Broxbourne in Hertfordshire (EN10); Woking in Surrey (GU21); Maidstone in Kent (ME15); and Preston in Lancashire (PR9) – will be asked to take a test.

How the test will be administered depends on their local authority. Some will be sending out mobile testing units to test people on their way to work or to the supermarket, while other people might receive tests through their letterboxes.

Some might even receive a knock on the door by a healthcare professional wanting to conduct the test there and then.

How do the tests work?

The surge testing kits will include PCR swab tests, which are used by the NHS at testing sites across the UK.

The test should be taken whether you have Covid-19 symptoms or not.

If you attend a mobile testing site everything will be done for you – all you need to do is turn up and have a swab taken, which staff will then send off on your behalf.

If you receive a test kit through your letterbox, you should follow the instructions to take a nose and throat swab. Package it up and either post it back or, if someone has said they will collect it, wait for them to arrive at your door.

The swab will be sent off to be analysed in a laboratory and you should receive your result within roughly 48 hours.

Do you need to self-isolate while you wait for results?

The current health advice still stands: you need to self-isolate if you test positive, have any symptoms, or are contact traced following contact with someone who tests positive.

If you’re not experiencing any symptoms, you are free to go about your business while you wait for your result. That said, experts recommend staying home where possible to try and reduce any potential transmission – and to remember ‘hands, face, space’.

Health secretary Matt Hancock has urged people living in the postcodes where cases of the South African variant have been detected to “stay home”.

“People in the postcode areas that I’ve outlined need to take extra special precautions,” he said. “The ‘stay at home’ message is there for everyone, but in particular in those areas, it is absolutely vital that people minimise all social contact and get a test when the opportunity arises.”

If you are experiencing symptoms of coronavirus when you take the test you should self-isolate until you receive your result.

If the result is positive, you should self-isolate for 10 days (or longer if your symptoms continue). If it’s negative, you can go about as normal while still adhering to lockdown rules.

Will you find out if you have the South African variant?

After the swabs are tested and a positive or negative result shows, scientists won’t be able to say whether you’ve tested positive for the new strain or not. This is because positive samples are then sent off to be sequenced – the process by which they identify which variant of Covid-19 you have had.

This takes longer – and HuffPost UK understands it’s unlikely people will be told if they do have the variant.

What are the benefits of surge testing?

The rapid response PCR tests aim to identify variant clusters and the extent of the spread of the variant, says Professor Rowland Kao, an expert in epidemiology and data science at the University of Edinburgh.

It’s thought one in three Covid-19 cases are asymptomatic, so this could be a way to spot many cases that would otherwise be missed. People who do test positive – whether they have symptoms or not – will be urged to self-isolate for 10 days and it’s hoped this will help reduce infection rates even more.

Any downsides?

This kind of rollout is “highly dependent” on individuals taking up those tests, as it remains a voluntary activity, says Prof Kao.

“As there is some evidence that current vaccines may be at least somewhat less effective against this variant, slowing its spread via surge testing and maintaining travel restrictions to prevent it jumping to other areas of the UK – if it has not done so already – will be important to keep Covid-19 infections continuing downwards at its current trajectory.”