Multiple travelers likely brought the coronavirus to Maine at various points late last winter, before the state’s first case was detected on March 12. And the strain of the virus that’s been circulating in Maine ever since largely matches the strain that circulated in New York this spring and subsequently spread to much of the rest of the country.
Those are some preliminary findings from scientists at The Jackson Laboratory who are helping Maine public health officials by analyzing and identifying the genetic profiles of strains of COVID-19 found in people in Maine.
With the Maine Center for Disease Control and Prevention focused on processing test samples and identifying how and where people contracted COVID-19, Jackson Lab researchers have partnered with the state agency to analyze Maine people’s test results to see what sort of mutations of the disease are appearing here, said Ryan Tewhey, an assistant professor at Jackson Lab in Bar Harbor.
Being able to identify different strains of COVID-19 as they emerge is important, Tewhey said, because there could be differences in how new strains spread or in the symptoms they present. Both the behavior and activity of people who spread the disease and the behavior of the disease itself are key aspects of being able to contain any disease outbreak, he said.
“It’s a relatively new thing to do it in real time,” Tewhey said of genetically sequencing a disease. “It’s good to keep on top of mutations of the virus.”
Tewhey — who prior to joining Jackson Lab worked at the Broad Institute in Cambridge, Massachusetts, where his research included identifying strains of Ebola — said he and other Jackson Lab researchers so far have analyzed and identified genetic profiles from 99 positive test results in Maine.
Predominantly, the results match a strain of COVID-19 associated with the spike of cases this past spring in New York, which were genetically traced to cases found mostly in Europe, he said. A different strain associated with another early outbreak in Washington state has been traced back to Wuhan, China, where the pandemic originated late last year. But other research has found the New York strain to be much more dominant in the U.S., showing that infected people who traveled from New York early in the pandemic likely caused outbreaks in much of the nation.
Of the Maine test results profiled so far at Jackson Lab, Tewhey said, about 30 show minor variable characteristics, which indicates that multiple people with different variations of the disease’s genome — or genetic profile — introduced COVID-19 to Maine in late winter.
A lack of such variability, he said, would indicate that the strain in Maine has had less time to mutate, which in turn would suggest that Maine cases could perhaps be traced back to one source or person.
Because Maine’s results do have some variability, they show that multiple people brought the disease to Maine at various times late last winter.
Maine CDC contact tracing — the process of interviewing infected people to identify the source of their infections and other people they’ve potentially exposed to the virus — has led to similar conclusions. Contact tracers in early April identified a traveling salesperson as the source of many of Maine’s early coronavirus cases, and Maine CDC Director Nirav Shah said the salesperson may have infected people in multiple states.
Tewhey said the lab will continue to help analyze genetic sequences, also called genomic sequences, of positive tests that it receives from state health officials — a process that can take two days for each test result it receives. It will continue to share the resulting data with the Maine CDC, scientists at Yale University and other biomedical research institutions in the Northeast, and national databases used by researchers.
“We have the capacity to [profile test results] as long as the state needs it,” Tewhey said.