The first UK case of nCoV infection in the United States was a soldier in the Colorado National Guard assisting the Covid-19 response in a nursing home.

Colorado state officials said the first person found to be infected with the B.1.1.7 strain was one of six state National Guard soldiers deployed to a nursing home in the town of Simla since December 23.

"We recorded one confirmed infection and one suspected infection. They were on support after the facility was short of staff and faced 100 percent of the people living there infected with the virus,"

These two cases were reported after the Christmas day test.

Concern is growing about the new nCoV strain called B.1.1.7, which experts say is 70% more contagious than the original.

South Africa recorded more than 300 cases of infection with a different CoV strain.