The number of reported coronavirus cases in the United States surpassed 5 million on Sunday, double the number since the end of June, as the Midwest grappled with new spikes and states across the South and the West fought to contain surges.

The 5 million mark comes just 17 days after the U.S. total exceeded 4 million, according to The Washington Post’s tracking. The previous million cases were also reported in about a two-week span.

Reported U.S. cases have doubled since late June, peaking on July 17 with a staggering 76,491 cases in a single day. The United States leads the world with a quarter of all global infections. Brazil and India follow, with 3 million and 2.1 million reported infections, respectively.

Here are some significant developments:

  • Top congressional Democrats on Sunday criticized President Trump’s new executive actions as weak and unworkable, while Trump administration officials defended the president’s moves and said they were necessary because Democrats wouldn’t compromise on a broad coronavirus relief package.
  • A cluster of coronavirus cases has emerged at a Georgia high school that drew national attention last week after students posted pictures and videos of their peers walking without masks in tightly packed hallways, according to a letter sent to parents over the weekend.
  • The United States tallied 50,002 coronavirus cases and 579 deaths on Sunday after five straight days of death tolls greater than 1,000, according to The Post’s tracking. The single-day death totals in Arkansas and Nevada set records, and new deaths were higher than current seven-day averages in Louisiana, Minnesota, Washington and West Virginia.
  • New York Gov. Andrew M. Cuomo (D) reported Sunday that his state, which was hit hard early in the pandemic, logged its lowest positivity rate yet: 0.78 percent. Of 65,812 test results submitted to the state Saturday, the governor said, 515 were positive.

The infections milestone was yet another sign that virus cases have continued to multiply as the United States collectively fails to contain the spread. Disparate parts of the country have responded to the pandemic differently, with some regions maintaining strict social distancing rules and other areas trying to carry out a slightly modified version of business as usual.

Among those for whom the pandemic is far from normal are about 30 million unemployed Americans, who have been going without enhanced federal unemployment benefits that expired July 31. Democrats and White House officials sparred Sunday over Trump’s executive actions seeking to address the pandemic’s economic fallout after negotiations over a third relief package dragged on for weeks with scant signs of progress.

Since the virus appeared on U.S. soil in mid-January, the country has hit milestone after milestone, throwing the magnitude of the crisis into sharper relief. The United States tallied its millionth case on April 28 after a month of a soaring number of infections and deaths mainly concentrated in the Northeast. Cases reached 2 million on June 11, 3 million on July 8 and 4 million on July 23, according to The Post’s tracking.

Those numbers probably remain an undercount of the true infection total, which would include the roughly 40 percent of virus carriers who health officials believe are asymptomatic. Testing nationwide remains too slow and too limited to serve as a reliable means for tracking and preventing the spread of cases, with patients in many parts of the country waiting a week or more to receive results.

“It’s unacceptable for the country to have testing come back a week or even two weeks later,” Tom Inglesby, director of the Johns Hopkins Center for Health Security, said Sunday on NBC’s “Meet the Press.” “It’s not useful at that point.”

Testing problems were especially pronounced in Kansas City, Mo., where patients are facing 14-day delays amid a sharp rise in the city’s cases. Asked in an interview with CBS News’s “Face the Nation” what the city needed to fix the backlog, Mayor Quinton Lucas responded: “Money.”

“We need more resources to get more testing, to get faster testing through,” the Democratic mayor said. “That’s the biggest challenge, and we’re going to continue to see this spread unless we get more testing efficiently for people. So I think money, a solution out of Washington, is key for not just mine, but all American cities.”

Since Ohio Gov. Mike DeWine received a false positive test result last week, health experts have worried the error could mislead people who are inclined to distrust the pandemic’s severity. DeWine, a Republican, addressed those fears Sunday on CNN’s “State of the Union,” saying rapid antigen tests like the one that yielded the false result should be used only for screening.

DeWine, who has since tested negative twice, said the more commonly used polymerase chain reactiontests are more reliable and should be trusted. He added that Ohio will continue moving forward with its partnership with six other states to get access to additional antigen tests.

“The antigen tests are fairly new, and the companies that are coming out with them, quite frankly, have the burden of showing how good they are,” DeWine said. “Could they be used in some situation? Yeah, they could be, but you have to understand going in that you could get the false positives, like happened in my case, or you could get the false negative.”

Other parts of the Midwest and the West have reported alarming increases in cases in recent days. Weekly averages for new infections were rising in Idaho, Illinois, Indiana, Kansas and the Dakotas, according to The Post’s tracking.

Schools continued to wrestle over whether to bring students back for in-person instruction, switch to remote learning or adopt a hybrid model. The Trump administration has pressured school districts to reopen five days a week, saying it is critical for students’ academic and emotional well-being. Many districts have disregarded the demands, citing concerns about the safety of students and staff.

The reopening of schools “must be watched closely,” Howard Forman, a health professor at Yale University, told The Post. “Nobody really knows what is going to happen, but we should begin to get an indication in the next three weeks.”

In Georgia, where infections have soared in the past month, a cluster of coronavirus cases emerged at a high school that went viral last week after students posted pictures and videos of their peers walking through crammed hallways without masks. An announcement from the principal at North Paulding High School that six students and three staff members were sickened validated fears that crowded conditions in the nation’s K-12 schools could facilitate virus transmission.

As universities anticipated beginning their own classes, a private student-housing company pushed contracted colleges to maintain dorm capacity, according to communications uncovered by a student’s public record request.

Summer weather continued to tempt people to forgo social distancing, and public officials pleaded with residents to follow coronavirus protocols. Chicago Mayor Lori Lightfoot (D) tweeted a photo of a crowd, mostly not wearing masks, and scolded them for the large gathering.

“It’s called a pandemic, people,” she wrote. “This reckless behavior on Montrose Beach is what will cause us to shut down the parks and lakefront. Don’t make us take steps backwards.”