The mutated strain was detected in a female Boston resident in her 20s who had traveled to the U.K., according to a statement from the public health department.
Though the woman tested negative before leaving the U.K., she became sick one day after her arrival in the U.S. and later tested positive. The CDC currently requires passengers traveling from the U.K. to the U.S. to provide negative COVID-19 test results within three days of travel. (As of Jan. 26, all international passengers flying into the United States will need to provide the same, per the CDC.) The statement did not specify when the woman was tested.
Contact tracers have interviewed the woman and identified her close contacts, according to the health department’s statement.
“The individual developed symptoms in early January and tested positive for COVID-19,” reads the statement released Sunday. “A genetic sample was sent to an out-of-state laboratory as part of the U.S. Centers for Disease Control and Prevention’s (CDC) established surveillance process to identify COVID-19 variants. The State Public Health Laboratory was notified last evening of the results.”
Health officials are re-interviewing the woman, and surveillance for variants is ongoing at the state’s public health lab.
Massachusetts joins 14 other states across the nation that have previously reported cases of the U.K. coronavirus variant. Data compiled by the CDC lists at least 88 cases of the variant, excluding the newly reported case in Massachusetts. This strain is believed to be about 50% to 70% more contagious but is not believed to cause more severe illness or death. The recently approved vaccines are believed to remain effective against the strain.
“Given the increased transmissibility of this variant and the number of states and other countries that have found infected cases, the Department expected the variant to arrive in Massachusetts eventually,” the statement continues.
Health officials urged mask use, physical distancing, staying home when sick, and getting tested to lower the risk of additional infections. Massachusetts reported 4,283 new coronavirus infections on Jan. 17, contributing to a total 448,311 cases. There are 13,372 reported deaths and over 2,100 people in the state hospitalized for the novel virus.
Younger populations (0-19, 20-29) account for the largest number of new infections.