From left, city employees Eric Swope and Matt Niven on Tuesday gather a wastewater sample from the manhole next to Brickyard Pond at Keene State College to be tested for COVID-19. They gather three 24-hour samples per week and send two to the lab for testing.

The COVID-19 variant first identified in the United Kingdom late last year is now the dominant strain being found in Keene’s sewage, according to the latest data from Keene State College’s wastewater testing project.

The highly contagious B.1.1.7 variant was initially detected in Keene’s wastewater in early April, with rates ramping up in the ensuing weeks.

“The U.K. variant has gradually been detected across the spring and is now the dominant strain in our wastewater,” said Jeanelle Boyer, a Keene State public health professor who helps lead the project.

The college, in collaboration with the city, has been collecting sewage samples to be tested for COVID-19 since the beginning of the school year.

Being able to test Keene’s sewage for the virus — which is shed in fecal matter — allows researchers to predict the potential for increased spread in the community, they told The Sentinel previously.

Beginning this spring, the company that tests Keene’s samples — Florida-based Geosyntec Consultants, which has offices throughout New England — has been capable of detecting B.1.1.7, as well as the B.1.351 variant first identified in South Africa.

Keene’s samples are collected from two access points in the city’s sewer system — one that captures Keene State’s campus and the surrounding neighborhoods, including downtown, and another that covers the rest of the city, as well as Marlborough.

Both variants have been detected in the city’s wastewater samples since early April, according to Boyer.

However, she explained that up until April 12, the variant levels were too low to measure precisely.

“This is suggesting that there is some there, they’re detecting it, but likely there are so few cases that there isn’t enough to quantify,” Boyer said of these early detections.

Levels of the B.1.351 variant have stayed low, but B.1.1.7 has continued to increase throughout the spring, she said.

As of April 12, B.1.1.7 was making up about 20 percent of the SARS-CoV-2 detected in downtown Keene, and nearly 100 percent from the rest of the city. (SARS-CoV-2 is the virus that causes COVID-19.)

By April 26 — the most recent data available — the variant made up over half of the SARS-CoV-2 found in downtown Keene, and almost all of that detected at the other site.

Boyer said while there is no definite answer, the difference in rates between the two sites could be attributed to the variability of samples, as well as one of the sites covering a wider area.

The Centers for Disease Control and Prevention said last month that B.1.1.7 had become the dominant strain in the United States. B.1.351 has also been found around the country.

Dr. Aalok Khole, an infectious disease physician at Cheshire Medical Center in Keene, said because of this, the B.1.1.7 variant circulating in Keene isn’t surprising.

“We should be concerned but it is not unexpected,” he said in an email. “As we have said in the past, even if we hadn’t detected these strains in large numbers, for several reasons, we had assumed they were here and circulating.”

Locally, Boyer said it’s hard to predict whether B.1.1.7 will continue to be the dominant strain in Keene, though she and Khole said the pandemic’s course locally will likely depend on the area’s vaccination rates.

“The vaccines that are being used are very effective against the U.K. variant,” Boyer said. “My expectation is as vaccination increases, as long as people do continue to receive the vaccine ... I’d suspect SARS-CoV-2 levels to come down and with that, the U.K. levels as well.”

Olivia Belanger can be reached at 352-1234, extension 1439, or obelanger@keenesentinel.com. Follow her on Twitter @OBelangerKS.