Less than three months ago, the coronavirus had so devastated South Dakota that its overcrowded hospitals flew patients to other states for treatment. An analysis of the data collected by Johns Hopkins University had shown that death rates from Covid-19 in North and South Dakota were the highest in the world. In one county in Montana, the hospitalization rate for the virus was 20 times the national average.
As in some previous trouble spots such as Arizona and Florida, the increase rose sharply as most of these states’ leaders and residents opposed bans and mask mandates for months. A nationwide mask mandate was never granted in South Dakota.
The tip in these states was as short as it was powerful. Today their new cases are about as high as they were last summer or early autumn. In North Dakota, which mandated masks at its peak in mid-November, the turnaround was particularly dramatic: the daily average of deaths per person is now the second lowest in the country, according to a New York Times database.
Through some measures, the trajectory of the three-state hotspot has mirrored that of the nation. After the US daily average for new cases peaked on Jan. 9, it took 37 days – until last Monday – for the rate to drop by two-thirds. It took South Dakota and Montana 35 days to hit the same mark after cases in those two states peaked in November. (North Dakota did it in 24.)
Deaths remain high nationally as Covid-19 patients can take weeks to die. The country continues to record an average of more than 2,000 deaths a day and is on track to hit 500,000 deaths in the next week.
Experts say the peaks in the northern Great Plains have subsided in large part for the same reason that U.S. case numbers have dropped: people have finally taken steps to save themselves in the face of a runaway fatal disease.
Apr. 20, 2021, 11:33 p.m. ET
“When the situation worsens and friends and family are in the hospital or die, people begin to adjust their behavior and cases decline,” said Meghan O’Connell, South Dakota epidemiologist and health advisor in the Great Plains Tribal Leaders Health Board, which represents the Native American population in the area. Native Americans, who make up about 5 to nearly 10 percent of the population in all three states, are far more likely to be infected with the virus than the general population.
During the worst weeks of the outbreak, from early November to late December, mask usage rose 10 to 20 percentage points in South Dakota and 20 to 30 percentage points in North Dakota, according to survey data from the University of Maryland.
Since then, the US vaccination campaign has gained momentum. North Dakota ranks fifth among the states for having given its residents at least one shot. South Dakota is seventh and Montana is eleventh.
Some experts see the breed of the coronavirus by these states as a crude test for the widely-disapproved idea that the pandemic should continue until the population gains herd immunity.
While the region hasn’t achieved herd immunity, it may have gotten closer than anywhere else in the United States.
The November outbreak put North and South Dakota at the top of the list in cases per person where they remain infected at 13 and 12.5 percent of their residents, respectively, according to a New York Times database. With around 9.2 percent, Montana is close to the middle of the national pack.
Just over 8 percent of Americans – about 27.9 million – are known to have had the coronavirus, but for many reasons, including the fact that asymptomatic infections can go undetected, the Centers for Disease Control and Prevention suggest that the real one Rate is 4.6 times.
According to Jeffrey Shaman, professor of environmental health science at Columbia University who models the future spread of the virus, by the end of 2020 at least six in ten Dakotans – and most likely more – could have gained some immunity to the virus. And in some places the percentage could be even higher.