Epidemiology of COVID Variant in Carver County


Day 362: Stay Safe Minnesota

Mapping of COVID outbreak in Carver County outbreak shows how a variant spreads in an alarming rate.

In the Star Tribune, Pulitzer Prize-winning reporter Jeremy Olson has an interesting virus spread case study in northern Minnesota Carver county. Minnesota Department of Health(MDH)’s COVID-19 response senior epidemiologist Hannah Friedlander observed in early January that two children from one Carver County school had their COVID infections came from the same, more infectious viral variant, genomic sequencing data revealed.

“Then came a cluster in a local hockey team, followed by an outbreak at an area child care facility. All were unusual for their high ‘attack rates‘, meaning more people exposed to the virus ended up infected.”

When we get a report in a team, it’s not one report or two reports. It’s half the team is down.

Hannah Friedlander, MDH Senior Epidemiologist (source: Star Tribune)
Screenshot source: Star Tribune

Michael Osterholm, University of Minnesota’s Center for Infectious Disease Research and Policy (CIDRAP) director said:

“This is some of the most amazing epidemiology I’ve ever seen.”

According to the Tribune, “an outbreak of at least 12 infections at one K-8 school was tied by one person to a sports team with five infections, which were linked to a local high school with more than 20 infections among students and teams. One student from that school had ties via a recreation center to two other people who tested positive.”

State health officials told that their mapping project revealed how some links in the cluster carried COVID-19 from one group to another, while others might be coincidences.

“There does seem to be this high attack rate associated with this variant, and so it has provided us with some insight as we look at other parts of the state.”

Dr. Ruth Lynfield, state epidemiologist (source: Star Tribune)

“The cluster ensnared four private schools, nine public schools, one child care center, 18 hockey teams, four basketball teams, three lacrosse teams, one soccer team and three fitness or recreation centers. Transmission occurred across county lines, with a B.1.1.7-driven outbreak among most girls in one Shakopee hockey team having a link back to the Carver cluster,” Tribune reports.

State health officials told reporters that such detailed mapping of the virus spread in other counties may not be logistically feasible. “We don’t have to watch it happen in each community. We can see the pattern and take action and intervene,” said Kris Ehresmann, state infectious disease director.

COVID-19 Vaccination Watch

According to the US Centers for Disease Control and Prevention (CDC) COVID vaccination tracker page (as of Mar 24, 9 a.m.) 169,223,125 doses have been distributed and 130,473,853 doses administered. According MDH COVID-19 Response vaccine data (as of Mar 22) a total of 2,221,672 doses of Covid-19 (Pfizer & Moderna) vaccines have been administered in Minnesota. According to the MDH latest tally (as of Mar 24) the confirmed COVID-19 cases in Minnesota are 508,541 (out of 8,006,344 tested) with 6,798 deaths.