By Ian Collier and Alix Culbertson::

A sixth person in the UK who tested positive for a Brazilian coronavirus “variant of concern” has been found in Croydon, south London.

The COVID-19 variant, first seen in the city of Manaus, is thought to spread more rapidly than the original virus and to be more capable of evading existing vaccines.

In total, six cases of the P1 coronavirus variant have been confirmed – three in England and three in Scotland.

All of the cases are linked to travel from Brazil to the UK.

During Friday’s Downing Street briefing, health secretary Matt Hancock confirmed the mystery person had been tracked down.

“Using the latest technology and with the dogged determination of our Testing and Tracing scheme, we have successfully identified the person in question,” he said.

Public Health England (PHE) adviser Dr Susan Hopkins revealed how the person was tracked down:

• On 26 February, three cases were identified but one had not left their contact details on the online form
• Forty people from PHE and Test and Trace teams, from laboratories, logistics and data analytics experts, started searching straight away
• As of 28 February, they had a single barcode from the test with the date and time it was processed at the lighthouse laboratory for testing in Cambridge
• The barcode revealed it was delivered through DHL’s home delivery service so they worked backwards from when it arrived in the laboratory to which testing hub it had come from and through the postal service
• That was overlaid with the geographical spread to look for a correlation in barcodes and where they had been distributed to
• This narrowed it down to two regions and 10,000 possible households
• After combining the region and the time window they tracked down every distribution centre and filtered it down to 379 households
• Then they used “enhanced contact tracing”, with call handlers calling, emailing and phoning all people who could have received a test in that time interval
• The calls narrowed it down to 27 individuals who were then called and texted again
• On 3 March, a person called the COVID 119 helpline and provided the same barcode number as the one they were looking for
• They were then interviewed “extensively”, which established their whole household had been in Brazil and they had been quarantining.

Two of the six cases were found in South Gloucestershire, with surge testing employed in the area to try and see if there are more people who have the virus.

The three people in Scotland who tested positive for the variant, oil workers returning home, were in the Grampian region in the north of the country.

Research has suggested that the Brazil variant may spread more easily than other examples of the coronavirus.

Mutations to the virus’s spike proteins mean that antibodies developed in the human body to fight other variants may not be as effective.

In Manaus, Brazil, almost 70% of the population had immunity from the first wave of COVID-19.

But at the start of this year, the variant spread through the Amazonas city, with hospitals reportedly being overwhelmed.

There were fears vaccines would not work against the variant but a University of Oxford study found the vaccine it developed with AstraZeneca is effective against it, a source told Reuters.