Official: Michigan may already have mutant COVID strain
No cases of the mutated COVID-19 virus identified in the United Kingdom have been found in Michigan, but the state's laboratory in Lansing is on the lookout for the strain, the state's top epidemiologist said on Wednesday.
Called B.1.1.7 variant, the virus is much more contagious than the current strain but is not believed to cause more serious illness. The mutated virus has been identified in COVID-19 patients in California, Colorado and New York.
"We have not yet detected it in Michigan," said Sarah Lyon-Callo, director of the Bureau of Epidemiology and Population Health at the Michigan Department of Health and Human Services. "I don't think we would be surprised if it was here already."
Lyon-Callo said that knowledge about the variant SARS-CoV-2 virus may change as more data emerges.
"At this time, we don't have any evidence that infections caused by the B.1.1.7 variant will cause more disease, but we do know that the variant identified in the U.K. has caused increased transmissibility," she said.
"It's impacted the steps the U.K. has had to take to control the virus's spread, and will require stricter adherence to medication."
People infected by the new strain pass the virus on to more people than do people infected with the virus that is already prevalent in the United States, she said.
The new variant strain is identified through genomic sequencing of the SARS-CoV-2 virus that causes COVID-19. Scientists identify the exact order of the building blocks that make up an organism's genes to establish its identity.
Epidemiologists measure transmissibility by something called an Rt value, or effective reproduction number. An Rt value of 1 means that an infected person will transmit the disease to one other person.
"On Nov. 11, our Rt value dropped below 1, which means that a person with COVID-19 is infecting less than one other person — which is a great way to bring the number of cases down in a community," Lyon-Callo said. "Since then, we're starting to see this Rt value creep back up again."
About 6% of genomic sequencing of the SARS-CoV-2 virus done in the United States has occurred in Michigan, at either the state's Bureau of Laboratories in Lansing, or one of Michigan's many universities, Lyon-Callo noted. So it's possible that the strain could be detected here.
"The MDDHS Bureau of Laboratories has one of the strongest public health programs in the nation," she said. "We were one of the first states to begin sequencing samples for COVID-19.
"So right now, we're working with local health departments so that if there is anyone who is positive and has a recent travel history to the United Kingdom, we can get a sample from that person and sequence that sample."
Case rates still high
According to Lyon-Callo, COVID-19 case rates have plateaued in Michigan after 46 straight days of decline, at 237 cases per million people.
"Cases have dropped for six weeks in a row, (but) the current daily case rate remains more than twice the rate for early October," she said.
The number of Michiganians tested for the virus dropped to about 33,000 per day over the Christmas holiday, Lyon-Callo noted. But the proportion of positive tests increased.
"We definitely need to get those (testing) numbers up so we can understand what is happening with the spread of the epidemic in the state," she said.
"Percent positivity has begun to increase in recent days," Lyon-Callo said, adding the state's positivity rate hit a low of 8.2% on Dec. 27, but is starting to creep back up.
"We're currently at 9.6% of tests coming back positive," the epidemiologist said.
Lyon-Callo noted that case numbers are trending upward in 33 states this week, eight more than were experiencing upswings the previous week.
Meanwhile, coronavirus deaths for the week of Dec. 20-26 stood at 572, a decrease of 181 deaths from the previous week — and down from the 799 who died during the week of Dec. 14.
According to Lyon-Callo, the best way for Michiganians to prepare for a potentially more infectious strain of the virus is to continue to mask-up and follow safety measures like social distancing and hand-washing.
"There continues to be a lower proportion of people who were quarantining when they became symptomatic, and this is very concerning," she said. "We need people to be separated from others if they've been exposed to COVID-19, because it can be spread asymptomatically.
"And this will become even more important as the B.1.1.7 variant enters the United States and may impact Michigan."