Nineteen new cases of the U.K. COVID-19 variant have been confirmed in Massachusetts, the Department of Public Health reported on Sunday. That brings the state's total to 29.
The first case of this variant, also known as the B.1.1.7 variant, was identified in Massachusetts on Jan. 17.
Out of the state's 29 identified cases, only four have been tied to recent travel. The DPH says this suggests most of the cases identified in Massachusetts are "community-acquired."
A majority of the cases — 17 of the 29 — have been found in Worcester County. Six have been in Norfolk County, two in Middlesex County, two in Plymouth County, one in Hampden County and one in Suffolk County, according to DPH.
Medical leaders in Worcester County don't yet know whether the higher numbers there mean the variant is more prevalent in that part of the state or that researchers there are checking more virus samples for the variant. City of Worcester officials say none of the confirmed cases of the variant have come from the city itself.
Dr. Richard Ellison, a professor at UMass Medical School and hospital epidemiologist at UMass Memorial Medical Center, is leading a research project that launched this month in collaboration with the Broad Institute and the CDC to determine the prevalence of coronavirus variants in Worcester County. At least some of the cases announced by state officials have come from samples Ellison and his team sent to DPH.
The PCR test that UMass uses to determine whether someone is positive for the coronavirus reacts in a certain way when the U.K. variant is present, "but that was accidental. It wasn't by design," Ellison said. Some, but not all, other labs in Massachusetts use the same kind of PCR test.
The flagging of virus samples as suspicious is helping Ellison's team and its partners identify the variant in Worcester County. He wants to see widespread genomic sequencing of virus samples.
"For us to be able to understand what's going to happen with variants, we need to do more comprehensive testing in every major metropolitan area in the state ... hopefully up to 5% or more of the all of the positive test results, so we can look for it," he said.
Dr. Michael Hirsh, medical director for the city of Worcester, says he hasn't yet received word on where the variant has been discovered in Worcester County.
With infectious disease experts predicting it will become the dominant strain of the coronavirus in the region within a couple of months, Hirsh stressed the importance of people maintaining physical distancing, proper mask wearing and other precautions — including getting vaccinated as soon as possible.
"If we can get needles in arms to the degree that I hope we will — it's a little bit of a race now — we do that, and I don't think the variant will have enough staying power to find the hosts that are susceptible," Hirsh said.
The highly-transmissible variant has caused surges of transmission in the U.K. and parts of California and Florida. Some studies suggest the variant could increase transmissibility by about 50%.
Two other variants of concern, according to the DPH, are the B.1.351 originally found in South Africa, and the P.1 variant originally found in Brazil, though neither have been identified in Massachusetts yet.
With additional reporting by WBUR's Lynn Jolicoeur
This article was originally published on February 14, 2021.