A case of the more contagious coronavirus variant first discovered in Britain was discovered in Colorado on Tuesday, Governor Jared Polis said. This is the first confirmed case of the variant in the United States.
The variant was detected in a man in his twenties with no travel history, Polis said. The man was isolated in Elbert County, southeast of Denver, he said.
“There is a lot we don’t know about this new variant of Covid-19, but scientists in the UK are warning the world that it is much more contagious,” Polis said in a statement. “The health and safety of the Coloradans is our top priority and we will be monitoring this case very closely, as well as all Covid-19 indicators.”
Scientists are worried about these variants but are not surprised by them. It is normal for viruses to mutate, and most of the coronavirus mutations have been found to be minor.
“It shouldn’t be a source of panic,” said William Hanage, an epidemiologist at Harvard University. “But that requires us to redouble our efforts to prevent the virus from spreading.”
Earlier this month, British researchers observed that the variant was becoming more prevalent in parts of Britain. Their subsequent research suggests that the variant – known as B.1.1.7 – spreads more easily than the others in circulation.
It is not yet clear why B.1.1.7 transmits more easily. The line has accumulated 23 mutations since separating from other coronaviruses. Researchers are studying some of the mutations to see if they allow viruses to invade cells more easily or to reproduce more.
There is no evidence that an infection with B.1.1.7 is more likely to lead to a severe case of Covid-19 or to increase the risk of death. But the speed at which the variant appears to be spreading could lead to more infections – and therefore more hospitalizations.
The UK government has responded to the emergence of B.1.1.7 by imposing stricter restrictions on the movement of people and the size of gatherings. In a preliminary study, British researchers found that schools may need to be closed and vaccination programs aggressively accelerated to avoid a surge in cases.
Countries around the world have implemented more stringent protocols for travelers entering from the UK. A new rule in the United States requiring inbound travelers from the United Kingdom – including American citizens – to show proof of a negative coronavirus test upon entry went into effect on Monday.
It is not known where B.1.1.7 was born. The UK has the world’s largest coronavirus genome sequencing system, which may be why the variant was first found there. Cases of the variant have also been identified in France, Spain and other European countries, as well as in Lebanon and Singapore. Health officials in Ontario, Canada said on Saturday they had identified two cases of the variant in a couple with no known travel or exposure history.
Because the United States sequenced far fewer genomes than Britain, American scientists suspected the variant may have already been in the country undetected. It seems they were right.
The fact that the Colorado man identified on Tuesday does not have a travel history raises the worrying possibility that B.1.1.7 is already well established in his community – and possibly elsewhere. “He didn’t teleport across the Atlantic,” Dr. Hanage said.