ROCHESTER, Minn. — The number of confirmed and probable cases of vaping-related serious lung illness in Minnesota have more than tripled in the last 28 days and are concentrated in the Twin Cities and surrounding suburbs, according to Minnesota Department of Health case investigation data provided at the request of Forum News Service.

On Sept. 6, Minnesota reached 17 confirmed and probable cases of the deadly illness. Four weeks later, that number stands at 61, with another 34 under review.

The cases are clustered in some of the most populous counties in the state.

As of Oct. 3, Hennepin County, with 14 cases, has the largest number of people hospitalized for what now appears to be a chemical damage to the lungs caused by vaping, followed by 7 cases each in Dakota and Ramsey Counties. Another 14 cases are distributed between suburban Anoka, Washington and Scott Counties. The case numbers then drop dramatically as the distance increases from the Twin Cities.

Though tissue samples have been analyzed at the Mayo Clinic, there are no reported cases in Olmsted County.

Source: Minnesota Department of Health
Source: Minnesota Department of Health

The location of the cases are of interest because just six weeks ago, the Centers for Disease Control characterized the illness as a largely Midwestern cluster made up of Wisconsin, Minnesota, Illinois, Indiana and California, suggesting wide regional variation in the outbreak nationally.

Additionally, while some cases have been associated with reports of using only nicotine products, a majority of the cases are believed to be associated with the use of illicit THC vaping products, according to the CDC, products that presumably travel in black market drug delivery pathways and which are not evenly distributed across the landscape. Finally, two of the largest illicit THC vaping cartridge busts in the country were recently recorded in Wisconsin and the Twin Cities north metro.

Two weeks ago, police in Bristol, Wis., discovered a residential-based operation storing 31,000 THC -filled cartridges and an additional 98,000 unfilled units, a so-called "pen factory," allegedly operated by a pair of 20- and 22-year-old brothers who authorities believe produced 3,000 cartridges a day. One week later, that seizure was eclipsed by the nearly 77,000 illicit THC cartridges located at a home in Coon Rapids, Minn. The cartridges included youth-directed products sporting names like Fruity Pebbles, Strawberry Shortcake and Apple Jacks.

As early as mid-August, Wisconsin reported nearly a third of all vaping-related illness cases in the country, at 30. With 69 as of early October, the state has since more than doubled that number, and Minnesota is closing in at 61. Iowa, by comparison, has reported just 23 cases so far.

On the most recent CDC map of nationally-identified cases dated Oct. 1, Minnesota stands in the second-highest quintile of cases in the country with nearby Wisconsin and Illinois.

Graphic: The Centers for Disease Control
Graphic: The Centers for Disease Control

More populous states in the eastern U.S. at that time confirmed fewer than 50 cases.

"It’s difficult to make comparative conclusions from the CDC map of cases by states," said assistant state epidemiologist Richard Danila in an email. "Minnesota does seem to be in the top five states by number of cases. However, it’s important to remember that the first cases were identified in Wisconsin and Illinois and relatively early on in Minnesota compared to other states. This suggests that whatever it is that is causing this outbreak originated in the Midwest. However, other states quickly also started seeing cases."

Danila, a lead adviser on the Minnesota investigation, said he does not believe the concentration of cases in the region can be attributed to better case identification.

"We cannot know whether or not our providers are better at identifying and reporting cases than other states," he said. "It does not seem reasonable to us that all or most of the states on the East Coast are poorer at identifying and reporting cases."

Danila also would not speculate about whether the THC cartridges located in Wisconsin and Minnesota were behind the case numbers. He argued for caution in extrapolating that the region is potentially saturated with deadly, scentless, black-market THC products associated with lung disease and targeting kids.

Meanwhile, faced with the latest Minnesota Student Survey showing one fourth of all 11th graders have recently vaped, and three quarters believe there is no risk in doing so, Gov. Tim Walz and state health and education officials on Thursday cautioned to not lose sight of the fact that all vaping is addictive, with the risks unknown.

"I'm fearful that kids may overlook the fact," said Walz, "that even if you didn't get damage to the lungs, there's still the nicotine addiction. Our job is is making people aware this is not a safe alternative to tobacco."