Covid: Which areas are being mass tested for variants?

Extra Covid tests are taking place in areas where new variants of Covid have been found.

It's to try to stop the spread of strains which may be able to get round some of the protection offered by vaccines.

Surge testing is used to prevent the spread of outbreaks of Covid - especially new, more contagious variants.

In specific locations (streets, postcodes or districts) there is increased testing and enhanced contact tracing.

Some testing is carried out by health officials going door-to-door.

Everybody aged 11 years and over who lives in, works in, or travels through the London boroughs of Lambeth and Wandsworth is being asked to take a Covid-19 PCR test.

Forty-four confirmed cases, and 30 probable cases, of the South Africa variant have been found.

All identified cases are isolating, or have completed, their isolation. Their contacts have been traced and asked to isolate.

Information on what to do is on the local authority websites:

The surge testing operation is the largest to date.

People living in certain parts of SE16 in the London Borough of Southwark are also being contacted - after a case linked to the Lambeth/Wandsworth cluster was identified.

Surge testing linked to the South Africa variant is also taking place in parts of:

Surge testing in several other areas has now been completed.

The Brazilian variant

The strain does not appear to cause more serious illness in the vast majority of people.

However, it is believed to spread more easily and vaccines may not work as well against it.

The South Africa variant

Like the Brazilian variant, the South African variant is not considered to be more dangerous.

However, there are concerns it could spread more easily and be more resistant to the vaccine.

The Kent variant mutation

Experts think the UK or "Kent" strain may also be more infectious. Some research suggests it may be associated with a 30% higher risk of death.

Cases discovered in Manchester in early February show a new mutation of the Kent variant called E484K which is also present in the South Africa variant.

The PCR (polymerase chain reaction) test

The PCR test involves swabbing your nose or throat, dropping the swab in a vial of liquid and sending it to a lab for analysis.

It is regarded as the most reliable test, but normally takes a day or longer to get a result.

People tested under the new variant surge programmes are being offered PCR tests.

The lateral flow test

This also involves a swab from the nose or throat, which is dropped into liquid. The solution is then added to a test strip which shows a result in 20-30 minutes.

Wherever you are in the UK, if you have symptoms you should book a free test online. You will be sent to a testing site or have a testing kit sent to your home.

If you have problems booking, call 119 in England, Wales and Northern Ireland or 0300 303 2713 in Scotland.

Anyone in England can now get two free lateral flow tests each week - even if they do not have symptoms.

Anyone who gets a positive result test must immediately self-isolate for at least 10 days. NHS Test and Trace will tell their contacts to isolate if necessary.

Self-isolating means not leaving home for exercise or even to buy food, medicines or other essentials.

People in England who fail to self-isolate after a positive test can be fined up to £10,000.

Anyone on a low income who has been told to self-isolate can claim a £500 payment.

Correction 2 March: A version of this story published on 1 March said that testing for variants was being carried out in the CM0 area around Southminster. It was in fact the CM13 area around Brentwood where additional testing was taking place.