South Korean soldiers wearing protective gears disinfect as a precaution against the new coronavirus at a train station in Daejeon, South Korea, Thursday, June 25, 2020. (Kim Jun-beom/Yonhap via AP)

Governments and businesses are ramping up precautions as coronavirus case numbers rise to dire new levels in parts of the U.S. and around the world, potentially wiping out two months of progress.

Indonesia was expected to pass the 50,000 mark for confirmed infections on Thursday. In Melbourne, health workers planned to go door-to-door to test more than 100,000 residents in a hot spot that threatens to undo the nation's success in battling the virus.

In the Indian capital of New Delhi, which has reported more than 70,000 cases, authorities said they would conduct house-to-house screening over the coming two weeks. With the city's hospitals overwhelmed, military personnel were providing care at makeshift medical wards fashioned from railroad coaches.

India reported a record high 16,922 cases on Thursday, taking the national total to 473,105, with nearly 15,000 deaths.

The Africa Centers for Disease Control and Prevention said the continent's cases have surged to more than 336,000, up by 10,000 from a day earlier. The Africa CDC chief said the pandemic on the 54-nation continent "is picking up speed very quickly" while shortages of testing materials and medical equipment remain severe in many countries.

Molly Beard wears a mask as she shares her experience becoming a world-class route setter Tuesday, June 24, 2020, at High Steppe Climbing Center in Yakima, Wash. (Amanda Ray / Yakima Herald-Republic via AP)

The actual numbers of cases everywhere, are thought to be far higher due to a number of reasons including limited testing.

World financial markets were rattled by the setbacks in fighting the pandemic, which cloud prospects for recoveries of economies mired in their worst downturn since the Great Depression of the 1930s.

Asian shares fell Thursday after the Dow Jones Industrial Average lost over 700 points overnight for a drop of 2.7% and the broader S&P 500 fell 2.6%.

In China, where the virus first appeared late last year, an outbreak in Beijing appeared to have been brought under control. China reporting 19 newly confirmed cases nationwide amid mass testing in the capital. Case numbers both nationally and in Beijing were up by only single digits from Wednesday.

South Korea was still struggling to quell an outbreak there, reporting 28 new cases on Thursday, mostly associated with nightlife, churches, a huge e-commerce warehouse and door-to-door sales. But the numbers have not reached the hundreds of new cases every day in late February and early March.

South Korean soldiers wearing protective gears disinfect as a precaution against the new coronavirus at a train station in Daejeon, South Korea, Thursday, June 25, 2020. (Kim Jun-beom/Yonhap via AP)

While some governments are considering more aggressive action to stem fresh outbreaks, in other places such precautions are being unwound.

Skyscraper-studded Dubai, in the United Arab Emirates, ended a monthslong nightly curfew, with the city-state's media office saying in a tweet that there would be "free move all day & night" as long as people wore masks and maintained social distancing.

European nations appeared on track to reopen their shared borders by July 1, and their EU representatives debated criteria for lifting restrictions on visitors from outside Europe. In Greece, aviation officials were visiting airports regional opens due to open to direct international flights on July 1.

Americans are unlikely to be allowed into EU nations, given how the pandemic is flaring in the U.S. and President Donald Trump's ban on Europeans entering the United States.

Robert Jackson, with Texas Department of Public Safety, attends the Blue Mass at the Basilica of Our Lady of San Juan del Valle on Wednesday, June, 24, 2020 in San Juan, Texas. A Blue Mass is celebrated annually for those employed in the field of public safety, which includes police officers, firefighters, corrections officers and paramedics. (Delcia Lopez/The Monitor via Ap)/The Monitor via AP)

American hospital administrators and health experts warned Wednesday that politicians and a public tired of being cooped up are letting a disaster unfold. The 34,700 COVID-19 cases reported Tuesday returned the U.S. to near its late April peak of 36,400 new cases in one day, according to a count kept by Johns Hopkins University.

New York Gov. Andrew Cuomo, New Jersey Gov. Phil Murphy and Connecticut Gov. Ned Lamont announced their states, which were devastated by early outbreaks that appear to be under control, will require travelers from certain states to quarantine for 24 days upon arrival.

The quarantine applies to people coming from states with a positive test rate higher than 10 per 100,000 residents on a seven-day average, or with a 10% or higher positive rate over seven days.

Several states have set single-day case records this week. They include Arizona, California, Mississippi, Nevada, Texas and Oklahoma. Some also broke hospitalization records, as did North Carolina and South Carolina.

Miso Fast (7), with jockey Jennifer Whitaker, overtakes Lochness (4), with jockey Alex Anaya, to win a horse race Wednesday, June 24, 2020, at Emerald Downs Racetrack in Auburn, Wash., on the first day of thoroughbred racing at the track since all professional sports in Washington state were curtailed in March by the outbreak of the coronavirus. No spectators were allowed, but online wagering was available and the races were streamed. Organizers hope to continue racing into October on a modified schedule. (AP Photo/Ted S. Warren)

The virus has been blamed for over 120,000 U.S. deaths—the highest toll in the world—and more than 2.3 million confirmed infections nationwide. On Wednesday, the widely cited University of Washington computer model of the outbreak projected nearly 180,000 deaths by Oct. 1.

"People got complacent," said Dr. Marc Boom, CEO of the Houston Methodist hospital system. "And it's coming back and biting us, quite frankly."

Alarmed, some states are moving to ensure more consistent use of face masks and other anti-virus measures.

North Carolina Gov. Roy Cooper, a Democrat, ordered people to wear masks in public as the daily count of hospitalizations and new cases hovered near records. In Florida, several counties and cities recently enacted mask requirements.

Nevada's governor announced the state will require use of face-coverings in public places to stem rising infections after casinos, restaurants and other businesses started reopening.

  • In this March 13, 2020, file photo, visitors take photos at Disneyland in Anaheim, Calif. Disney is proposing to reopen its Southern California theme parks in mid-July after a four-month closure due to the coronavirus, the company said on Wednesday, June 10, 2020. Disney is postponing the mid-July reopening of its Southern California theme parks until it receives guidelines from the state. The company announced Wednesday, June 23, 2020, an indefinite postponement for Disneyland and Disney California Adventure in Anaheim. (AP Photo/Amy Taxin, File)

  • Olinda Silvano from the Shipibo Conibo ethnic group, talks to a member of an NGO dressed in protective gear against the new coronavirus, during the celebration of the feast of Saint John the Baptist, the patron saint of the Peruvian Amazon, in the Cantagallo neighborhood of Lima, Peru, Wednesday, June 24, 2020. The neighborhood reopened about 10 days ago after it had been under strict quarantine due to an outbreak of COVID-19. (AP Photo/Rodrigo Abd)

  • In this Tuesday, June 23, 2020, photo, a "Face Covering" sign is shown at Snider Bros. Meats, in Holladay, Utah. (AP Photo/Rick Bowmer)

  • Colorado Governor Jared Polis wears a face mask as he leaves a news conference about the state's efforts to stop the spread of the new coronavirus Wednesday, June 24, 2020, in Denver. (AP Photo/David Zalubowski)

Dr. Peter Hotez, an infectious-disease expert at the Baylor College of Medicine in Texas, said he worries that states will squander what time they have to head off a much larger crisis.

"We're still talking about subtlety, still arguing whether or not we should wear masks, and still not understanding that a vaccine is not going to rescue us," he said.

Worldwide, over 9.4 million people have been confirmed infected, and nearly 500,000 have died, by Johns Hopkins' count.

Dr. Michael Ryan, the WHO's emergencies chief, said when countries will hit their peak numbers of infections hinges entirely on what people do.

"There are no magic answers. There are no spells here. You can't divine this away," Ryan told reporters in Geneva. "We have to act at every level."