Covid-19 Live Updates: U.S. Death Toll Hits New Single-Day Record

After weeks of surging coronavirus cases, states in the Midwest are seeing the curve begin to flatten, even as other parts of the U.S. experience a fresh rise and health experts warn the impact of Thanksgiving hasn’t been fully felt.

The seven-day average of new cases in Michigan, Illinois, Iowa, Minnesota and the Dakotas has declined this week compared with a week earlier, according to data from the Covid Tracking Project. The seven-day average smooths out irregularities in data reporting, providing a clearer picture of trends.

The potential flattening is likely due to a combination of new restrictions and personal behavioral changes in response to a surge in cases, said Andrew Brouwer, an assistant research scientist in epidemiology at the University of Michigan.

Covid-19 infections soared across the upper Midwest this fall, a precursor to the rampant spread that would follow across much of the U.S. Now, the coasts and much of the South are reporting an increasing number of coronavirus cases, and hospitals in some places have become inundated with critically ill patients.

California, most of which is now under stay-at-home orders, has reported a significant rise in Covid-19 cases, which officials have said is linked to the Thanksgiving holiday. The state’s seven-day average on Tuesday stood at 24,193, up from 14,404 the previous week.

In Michigan, the seven-day average in cases has dropped to the high 6,000s after being in the 7,000 range for the second half of November.

“We have achieved some progress,” said Bob Wheaton, a spokesman for the Michigan Department of Health and Human Services. But, he added, the state is still in a second wave.

The percentage of Covid-19 tests that come back positive remains high, at over 14%, Mr. Wheaton said—nearly four times the number seen in the beginning of September. Deaths, he added, are more than seven times higher than in early October.

Gov. Gretchen Whitmer, a Democrat, on Monday extended restrictions on many types of indoor gatherings for another 12 days, saying the state needed more time to determine the full effect of Thanksgiving travel and meals.

Mr. Brouwer, the University of Michigan scientist, said it is still too early to know that impact. “Because daily case counts are so high now, even flattening or slightly decreasing incidence will continue to put further pressure on our already taxed healthcare systems,” he said, adding that deaths, which lag new cases by three to four weeks, will continue to climb.

Iowa, which had a seven-day average of more than 7,500 new daily cases in mid-November, is now registering just over 2,000 cases a day, according to a Wall Street Journal analysis of Johns Hopkins University data.

“We’ve made good progress over the last few weeks, but our ultimate goal is to get virus activity to a level that we can manage over the next few months,” Republican Gov. Kim Reynolds said at a recent news conference where she announced an extension of mask requirements and gathering limits by another week.

To do that, health experts say, it’s necessary that people accept and follow such restrictions.

“We understand enough about Covid to know that whether it rises or falls in the coming weeks has to do with population compliance with the basic control measures,” said Mark S. Dworkin, professor of epidemiology at the University of Illinois at Chicago. “There is no magic to predicting whether Covid rises or falls.”

Kris Ehresmann, infectious disease director at the Minnesota Department of Health, believes some measures the state took to limit the virus’s spread may have had an impact. The state’s seven-day average of new cases was 5,177.4 on Wednesday, according to a Journal analysis of Johns Hopkins data. That’s down from a high of 7,051.6 on Nov. 20.

While lower numbers are a good sign, it’s too soon to say if that state has peaked, Ms. Ehresmann said.

“We cannot let up our guard right now,” she said. “This has been a very tough year for everyone, but we do have a light at the end of the tunnel with a vaccine on the way.”