NEW YORK -- While deaths from the coronavirus in the U.S. are mounting, public health experts are seeing a flicker of good news: A second surge of confirmed cases appears to be leveling off.
However, scientists are warning that the trend is driven by four big, hard-hit places -- Arizona, California, Florida and Texas -- and that cases are rising in close to 30 states in all, with the outbreak's center of gravity seemingly shifting from the Sun Belt toward the Midwest.
Based on a seven-day rolling average, daily cases of the coronavirus in the U.S. fell from 67,317 on July 22 to 65,266 on Wednesday, according to data kept by Johns Hopkins University. That is a decline of about 3%.
Researchers prefer to see two weeks of data pointing in the same direction to say whether a trend is genuine. "But I think it is real, yes," said Ira Longini, a University of Florida biostatistician who has been tracking the coronavirus and has been a source of disease forecasts used by the government.
The Associated Press found that the seven-day rolling average for new cases plateaued over two weeks in California and decreased in Arizona, Florida and Texas.
The trends in Arizona, Texas and Florida are "starting to bend the curve a bit," said Jennifer Nuzzo, a Johns Hopkins public health researcher. Those states, along with California, have been pouring large numbers of cases each day into the national tally. So when those places make progress, the whole country looks better, she said.
Also, in another possible glimmer of hope, the percentage of tests that are coming back positive for the virus across the U.S. dropped from an average of 8.5% to 7.8% over the past week.
Some experts wonder whether the apparent caseload improvements will endure. It's also not clear when deaths will start going down. Covid-19 deaths do not move in perfect lockstep with the infection curve, for the simple reason that it can take weeks to get sick and die from the virus.Gallery: Coronavirus scenes, 7-30-2020
As for the future, "I think it's very difficult to predict," said Dr. Anthony Fauci, a national infectious-diseases expert.
The virus has claimed more than 151,000 lives in the U.S., the highest death toll in the world, plus more than 669,000 others around the globe.
Over the past week, the average number of deaths per day in the U.S. has climbed more than 25%, from 843 to 1,057. Florida on Thursday reported 253 more deaths, setting its third-straight single-day record. The number of confirmed infections nationwide has topped 4.4 million.
On Thursday, Gov. Ron DeSantis spoke to reporters after watching the launch of the Mars rover in Meritt Island and was asked about large crowds gathering to watch the liftoff, many of whom were not wearing masks.
"Our guidelines have been that physical distancing is important, closed sustained contact is what is the best mechanism for transmitting the virus," DeSantis said before lifting up a mask. "If you can't maintain the physical distance, wearing the mask, this may be able to stop some of the droplets. It doesn't stop them all."
DeSantis has not issued a statewide mask mandate.
With the outbreak heating up in the Midwest, Democratic Wisconsin Gov. Tony Evers ordered masks worn statewide because of a spike in cases, joining some 30 other states that have taken such measures.
Evers declared a new public health emergency and ordered the wearing of masks for anyone age 5 and older, starting on Saturday for all enclosed spaces except a person's home. The new order also applies to outdoor bars and restaurants, except when people are eating or drinking.
Anyone who violates the order would be subject to a $200 fine. The order is scheduled to be in force until Sept. 28.
Republican Assembly Speaker Robin Vos said he opposes a statewide mandate, but he indicated that he wouldn't sue to stop it like he did the "safer at home" order.
"There are certainly constitutional questions here," Vos said. "I would expect legal challenges from citizen groups."
Wisconsin has had more than 52,000 confirmed cases of the coronavirus and 919 deaths from covid-19 since the pandemic started.
The latest surge in cases became evident in June, weeks after states began reopening after a deadly explosion of cases in and around New York City in the early spring. Daily case counts rose to 70,000 or more earlier this month. Deaths, too, began to climb sharply, after a lag of a few weeks.
Some researchers believe that the recent leveling-off is the result of more people embracing social distancing and other precautions.
"I think a lot of it is people wearing masks because they're scared," Longini said.
But Dr. Ali Khan, dean of the University of Nebraska College of Public Health, said the trend could also be because of natural dynamics of the virus that scientists to do not yet understand.
Without robust testing and other measures to keep the virus in check, a third peak is possible -- or even likely -- given that only an estimated 10% of Americans have been infected so far, experts said. And there's no reason to believe the peak can't be larger than the first two.
"This disease will continue to hopscotch around until it finds tinder -- susceptible individuals -- like any good fire," said Khan, a former top infectious-diseases outbreak investigator at the Centers for Disease Control and Prevention.
Fauci said he is "somewhat comforted" by the recent plateau. But a stabilization of cases at around 60,000 is "still at a very high level." He said he is also worried about rising percentages of tests coming back positive in states like Ohio, Kentucky, Tennessee and Indiana.
"That's a warning sign that you might be seeing a surge," Fauci said. "They've really got to jump all over that."
In Washington, President Donald Trump for the first time publicly floated the idea of delaying the Nov. 3 presidential election during the pandemic, warning that increased mail-in voting could result in fraud. The notion ran into immediate resistance from top Republicans and Democrats alike.
Meanwhile, Speaker Nancy Pelosi and Capitol officials issued broad new mask requirements Wednesday after Republican Texas Rep. Louie Gohmert, 66, tested positive for the coronavirus.
Pelosi said all House members will be required to wear masks when voting on the chamber's floor and that one will be provided if anyone forgets. Several hours later, the House sergeant-at-arms and the Capitol's top physician issued an order requiring masks inside House office buildings, with few exceptions. That mandate went into effect at 8 a.m. Thursday.
Pelosi said failure to wear a mask on the House floor is a "serious breach of decorum" for which members could be removed from the chamber. Members will be able to temporarily remove their masks while speaking, however. In the House office buildings, people can remove them to eat, drink and give interviews, among a few other specific situations.
Gohmert tested positive just before he was scheduled to travel to his home state with the president Wednesday. He was forced to cancel his plans and was immediately criticized by colleagues for not always wearing a mask. "A selfish act," one lawmaker said.
An eight-term lawmaker, Gohmert participated in the House Judiciary Committee hearing Tuesday where Attorney General William Barr testified. Before the hearing, Gohmert was seen approaching the meeting room behind Barr, and neither man was wearing a mask.
Gohmert also voted on the House floor Tuesday and attended a House Natural Resources Committee hearing, where a staff member sat close behind him on the dais as he talked without a mask. The chairman of that committee, Democratic Rep. Raul Grijalva of Arizona, said he would self-quarantine.
"In the meantime, my work schedule and the lives of my employees are disrupted," Grijalva said. "This stems from a selfish act by Mr. Gohmert, who is just one member of Congress."
England suffered a more widespread coronavirus outbreak than its European neighbors and had the highest level of excess deaths during the pandemic, according to an analysis of more than 20 countries released Thursday by the U.K.'s Office for National Statistics.
Excess mortality is a term used in public health to refer to the number of deaths above what was expected under "normal" conditions.
Spain had Europe's highest national mortality peak, with deaths at the start of April soaring 138.5% above the five-year average, almost 2½ times the usual number, according to analysis of figures from British authorities and the European Union statistics agency, Eurostat.
England had the second-highest peak, with excess mortality spiking to more than double the average, 107.6%, in mid-April. England also had the biggest overall increase and the longest continuous period of excess mortality of the countries compared.
By the end of May, the cumulative mortality rate in England was 7.55% higher than the five-year average. Spain was second, with 6.65% more deaths than usual.
The biggest regional spikes were in central Spain and northern Italy. In Bergamo, Italy, the death rate in March hit 847.7% above the five-year average.
Britain's official coronavirus death toll stands at just over 46,000, the third-highest total in the world after the United States and Brazil.
Prime Minister Boris Johnson's government says there will be an independent inquiry into why the U.K. has had such a high death toll.
Asked Thursday about the death rate, Johnson said "this country has had a massive success now in reducing the numbers of those tragic deaths," and urged people to be vigilant about maintaining social distancing.
In France, the coronavirus infection rate has almost doubled over the past three weeks, requiring "quick and sizable efforts" to contain the surge, according to the nation's public health agency.
The number of new cases in France is increasing by more than 1,000 a day and the spread accelerated this week, the agency said in a statement. The average weekly infection rate has jumped to 10.2 cases per 100,000 people, an increase of 78% compared with three weeks ago. That tops the "vigilance threshold" of 10 cases per 100,000.
Summer gatherings with family and friends, as well as cultural events and festivals, are particularly at risk of becoming virus-spreading events, the agency said. The number of new confirmed cases rose by 1,377 on Thursday.
Information for this article was contributed by Mike Stobbe, Nicky Forster, Alan Fram, Adriana Gomez Licon, Brendan Farrington, Scott Bauer, Jill Lawless and Mary Clare Jalonick of The Associated Press; and by Alan Katz of Bloomberg News.