The coronavirus is always restless, always searching for new people in new places to infect. These days, even as the summer wave fades in the Sun Belt states, several Midwestern states are seeing case numbers rise. They look like the new Covid-19 hot spots.

“The Midwest is taking off,” William Hanage, a Harvard epidemiologist, told me over email. “It’s not going to skyrocket, but there is a clear signal there and it is close to making up for the gains across the Sun Belt.”

Here are the regional trends in chart form, via the Covid Tracking Project:

This is yet another warning against focusing too much on national trends. There were nearly 70,000 new cases every day in late July; today, the number of daily new cases is closer to 40,000.

Most of that improvement can be explained by falling case numbers in Arizona, California, Florida, and Texas, the summer’s hottest hot spots. But it’s being partially offset by accelerating spread in the Midwest, concentrated primarily in four states: Iowa, Kansas, North Dakota, and South Dakota.

covered Hawaii’s problems. Illinois has seen particular counties run into trouble. The trend lines in Indiana, Kentucky, and Minnesota are not encouraging.

But going by our tried-and-true metrics for evaluating the state of a state’s outbreak — changes in daily new cases, new cases per million people, and the positive test rate — those four states along with Alabama (which Vox covered a month ago) appear to be in the worst shape.

To recap why those metrics are important:

• Changes in daily new cases should be self-explanatory, demonstrating trends in the raw count of how many people in a state are confirmed to have contracted Covid-19 each day.
• New cases per million people reflects how saturated a state is with new coronavirus cases, adjusted for population.
• Positive test rate should be below 5 percent in order for public health officials to be confident they are detecting most new cases. If the figure is higher than that, and if it is increasing, that suggests uncontrolled spread that is not being effectively surveilled.

So let’s run through, in brief, what’s happening in these newly emerging Covid-19 trouble spots.

The stats, via Covid Exit Strategy:

• The number of daily new cases is up 192 percent over the last two weeks
• Daily new cases per million people is 354, the highest rate of new infections in the country
• The positive test rate is 22.2 percent, the highest figure among states and more than doubled from two weeks ago

As you can see, South Dakota ranks an ignominious first in all of the leading indicators for a worsening outbreak. Hospitalizations also doubled from a low of 35 in early August to 78 as of September 1.

Those numbers look small, but remember, South Dakota is a state of fewer than 900,000 people. The smaller populations are one reason experts do not expect the gross numbers to rebound to the same levels seen in the summer, when some of our biggest states were being ravaged by Covid-19.

But the virus can still put a strain on smaller communities. For now, the state’s hospitals still appear to have ample capacity, though hospitalizations lag behind new cases. That will be a key metric to watch in the next few weeks.

It’s hard to be sure what’s behind this spike in cases. South Dakota still doesn’t have a mask mandate, and Gov. Kristi Noem has said she won’t issue one, nor will she impose a stay-at-home order. The state has not placed meaningful restrictions on businesses or other public activities, according to Boston University’s state policy database.

There was also the Sturgis motorcycle rally last month, which state health officials have linked to more than 100 cases of South Dakotans contracting Covid-19. The number of people infected at the state’s universities ballooned from less than 50 in mid-August to more than 550 by the end of the month. There have been another 200 cases reported recently in K-12 schools.

Younger people are thankfully less at risk of severe illness and death from Covid-19. But older people also work in schools, and any spread in educational settings risks the virus seeping out into the broader community, exacerbating these already worrisome trends.

• The number of daily new cases is up 77 percent over the last two weeks
• Daily new cases per million people is 332, the second-highest rate of new infections in the country
• The positive test rate is 20.1 percent, the second-highest figure among states and doubled from two weeks ago

North Dakota is trailing just behind its southern neighbors on most of these metrics. Hospitalizations have been steadily rising since the first of July, up from 20 people then to more than 60 now.

The New York Times noted that the city of Grand Forks, home to the University of North Dakota, had seen one of the highest growth rates of cases in the country recently. UND is currently reporting more than 200 students, faculty, and other staff with active Covid-19 cases; North Dakota State University in Fargo says it has had more than 90 positive cases in the last two weeks. For context, the entire state has been reporting about 250 new cases on average every day of the last week.

Like South Dakota, North Dakota does not and has never had a mask mandate. The state did close some businesses in March, when the outbreak was largely contained to the New York City area, but they began reopening in May and no new restrictions have been put into place.

• The number of daily new cases is up 90 percent over the last two weeks
• Daily new cases per million people is 300, the fourth-highest rate of new infections in the country
• The positive test rate is 18.5 percent, the third-highest figure among states and nearly doubled over from two weeks ago

In addition to the high rate of daily new cases and the high positivity rate, hospitalizations have doubled since the beginning of July and deaths are also starting to increase. Iowa had been down to reporting one new death per day two months ago; now it is reporting at least 10 on average.

Many of the new cases have been linked to students returning to the University of Iowa and Iowa State University’s campuses. The state’s lakes region, a popular summer vacation destination, has also turned into a regional hot spot, as Emily Mendenhall reported for Vox.

According to the Des Moines Register, the Trump White House’s coronavirus task force has warned Iowa to take measures to curb its accelerating outbreak. Federal officials have urged the state to close bars in most counties, require people to wear masks in public, and test all incoming college students for Covid-19.

Yet Gov. Kim Reynolds is declining to impose any new mitigation measures. Iowa is another one of the 16 states without a mask mandate. Most business restrictions were lifted in May. And now Iowa State says it will allow 25,000 people to attend its season-opening football game on September 12.

Asked about having such a large crowd amid a worsening outbreak, Reynolds told reporters: “If you don’t feel safe, don’t go.”

• The number of daily new cases is up 26 percent over the last two weeks
• Daily new cases per million people is 206, the eighth-highest rate of new infections in the country
• The positive test rate is 16 percent, the fifth-highest figure among states and increasing from two weeks ago

Kansas is in not quite as bad shape as the Dakotas or Iowa, but its high rate of new cases and high positive test rate are a concerning combination.

College students returning to campus again seem like a likely contributor to the increased spread. The Kansas City Star reported that counties in the state that have colleges in them saw more growth in Covid-19 cases than the state as a whole. Kansas State University’s football team and several sororities at the school have seen virus clusters.

The state has been more aggressive about trying to contain the virus than some of its neighbors. Gov. Laura Kelly imposed a mask mandate on July 1 and she waited until the end of June to allow bars to reopen. Still, the metrics in the state suggest the virus has started spreading in the community again.

And the next few weeks could be critical. According to the Hutchinson News, Under a deal reached with the Republican-controlled legislature earlier this year, Kelly would be allowed to reintroduce some restrictions and extend the state’s emergency declaration in mid-September — if she secures the approval of some GOP state lawmakers.

It is not at all clear from the News’ report that the governor and her Republican counterparts can reach a new agreement. That failure could prevent the state from taking more aggressive actions to stem this new spike.

This story appears in VoxCare, a newsletter from Vox on the latest twists and turns in America’s health care debate. Sign up to get VoxCare in your inbox along with more health care stats and news.

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