A COVID-19 variant first found in the U.K. is infecting Americans at a pace that far outstrips the original strain, which arrived in the spring.
In the 43 days since B.1.1.7 was first found in the US, more than 900 cases have been reported. At around the same point, the first strain had infected only 165 people.
Even as overall daily cases decline, the B.1.1.7 mutation is burgeoning more quickly than others first seen in Brazil and South Africa. As of Tuesday, there were 932 reported cases of the U.K. variant among 34 states, according to data from the US Centers for Disease Control and Prevention.
Florida reported the most variant infections at 343, followed by California. The two states account for more than half of the national variant cases. Early research has shown the strain to be more transmissible and may carry an increased risk of death.
Researchers are still learning about the new iterations, and cases in the US are likely undercounted due to capacity constraints in identifying strains. The CDC bases its figures on a sampling of positive SARS-CoV-2 specimens. As of late January, the agency’s surveillance system was capable of testing about 750 samples per week, and the CDC is contracting with commercial labs for added capacity.
Increases in variant cases come as daily infections across the country are seeing the most significant drop since the pandemic began. But the new versions are spreading quicker than Covid-19 initially did in the US and one could surpass it to become the predominant virus.
The U.K. is a world leader in genomics, the science used to identify new strains. The country’s Department of Health and Social Care announced last month it would share its capacity to test for variants with other countries.
Nationally, the US posted 92,986 new Covid-19 cases on Tuesday, bringing the seven-day average to 107,612, Covid Tracking Project data show. As of early Wednesday, there had been at least 468,500 reported deaths in the US, according to Johns Hopkins University.
No states posted single-day case records Tuesday, and average cases were flat or falling in all 50 states and Washington, D.C., compared with the week prior.
New York had the most people hospitalized with the virus per capita, with 405 hospitalized per million.
Arizona reported the most new cases per million people at 602.