Surge testing is to begin in parts of Birmingham after a case of the Covid-19 variant first identified in South Africa was confirmed there.
The Department of Health and Social Care said the patient had “self-isolated and their contacts have been identified”.
Health officials added in a statement: “Initial investigations indicate that this case is not linked to a case previously identified in the Birmingham and Sandwell areas.”
The testing will be targeted at households in the city’s Alum Rock, Glebe Farm and Tile Cross areas.
Officially, 600 people in the UK have contracted the South African coronavirus variant according to the government website – but that was based on figures up to April 14.
This is unlikely to be an accurate portrayal of how far the mutation has spread since hundreds of thousands of people have been swabbed during previous rounds of surge testing elsewhere in the country, on top of which it can take days for samples to have genomic sequencing carried out. The process is the only way to detect which variant of coronavirus someone is infected with.
Other areas where cases of the South Africa variant have been found include the London boroughs of Barnet, Harrow, Hillingdon, Lambeth, Southwark and Wandsworth.
The South Africa strain is classed as a “variant of concern” – the most serious classification issued by Public Health England – because there are fears it may be less susceptible to vaccines and could spread more easily.
The DHSC said everybody aged 16 years and over who is contacted from the new areas would be “strongly encouraged to take a Covid-19 PCR test”, whether or not they are symptomatic.
For anyone testing positive for a key variant, enhanced contact tracing – looking back over an extended period in order to determine the route of transmission – will be used.
Meanwhile, anyone with symptoms is urged to book a free test online or by phone.
And the government is asking people to continue using twice-weekly rapid lateral flow testing alongside any PCR surge testing they do.
Last week surge testing was introduced in the city’s Ladywood, Jewellery Quarter and Soho ward, after a single positive case of the same variant.
Speaking at the time, the city’s public health director Dr Justin Varney said: “Testing is an important part of containing the spread of the virus.
“This new variant from South Africa presents a new risk so it is essential that all adults in the affected areas take up this offer of PCR testing to help us contain the spread quickly and identify any further local cases.
“There is financial and practical support available for those who test positive and have to isolate, and their contacts, and it is vital we all play our part in controlling this new challenge.”
Viruses by their nature mutate often, with more than 18,000 mutations discovered over the course of the Covid-19 pandemic, the overwhelming majority of which have no effect on the behaviour of the virus.