More than 1,400 coronavirus variant cases have now been detected in Massachusetts, according to state officials.
The Massachusetts Department of Public Health on Monday said 1,280 cases have been confirmed of the fast-spreading and more deadly variant that emerged in Great Britain, along with 113 cases of the variant that emerged in Brazil, and 12 cases of the variant that emerged in South Africa.
The 1,405 total variant cases in Massachusetts was up sharply from 1,071 as of the middle of last week. The numbers have been growing since the state’s first case, a British variant, was announced Jan. 17.
The US Centers for Disease Control and Prevention over the weekend reported lower figures for Massachusetts, saying 1,100 cases had been confirmed of the British variant, along with 102 cases of the Brazilian variant and 12 cases of the South African variant.
Those numbers meant the state had the fourth highest total number of British variant cases detected among the states, the second highest number of Brazilian variant cases, and the 13th highest number of South African variant cases, according to the CDC.
A DPH spokeswoman said the CDC numbers for Massachusetts would be updated Tuesday with the DPH numbers.
Experts and officials say the totals underrepresent the actual number of cases circulating. The genomic sequencing needed to look for variants is done only on a limited number of tests. The numbers are “based on a sampling of SARS-CoV-2-positive specimens and do not represent the total number of ... cases that may be circulating,” the CDC itself says on its website.
Elsewhere on its website, the CDC estimates that nationally, in the two weeks ending March 13, 27.2 percent of coronavirus cases were caused by the British variant, 0.5 percent were caused by the Brazilian variant, and 0.5 percent were caused by the South African variant.
The variants have caused concern because of their potential to spread faster and cause more severe disease. The British variant, which has become the most common in the United States, is about 60 percent more contagious and 67 percent more deadly than the original form of the coronavirus, according to the most recent estimates. But the vaccines currently being administered across the United States offer good protection against the British variant.
There are two other official “variants of concern,” B.1.427 and B.1.429, which are known as the California variants. The CDC and DPH did not provide tallies for those variants. Nationally, the CDC estimates the prevalence of B.1.427 at 4.3 percent and B.1.429 at 9.1 percent.
The CDC’s efforts to track the spread of coronavirus variants came under fire early this year. But they have substantially improved recently and are expected to continue to improve, in large part because of the $1.75 billion in funds for genomic sequencing in the stimulus package.
Material from Globe wire services was used in this report.
Martin Finucane can be reached at firstname.lastname@example.org.