Why South Korea may have more coronavirus cases than the US

Global health experts say the speed and scope of South Korea’s novel coronavirus diagnostic capability exhibit impressive and significant lab capabilities that no other countries, including the U.S., can match at the moment.

South Korea had tested a total of 66,652 people for the COVID-19 coronavirus virus as of 4 p.m. local time Thursday, whereas Japan had reported administering roughly 1,890 tests and the U.S. only 445. The huge discrepancy compared to other countries reflects how quickly South Korea’s numbers have been rising, experts say.

The total number of confirmed cases so far in South Korea is 1,766, up 505 from the day before. Of the 66,00 people who have been tested, more than 25,000 are still awaiting lab results.

More than 10,000 people a day are being tested around the clock, propelled by a sense of concern that the virus may spread outside of Daegu area, where around 80 percent of all confirmed cases have been found.

"This week is crucial for us in determining whether we have successfully dealt with COVID-19," South Korea Prime Minister Chung Sye-Kyun said.

The tests are being run at 79 designated health centers, in addition to authorized private hospitals and public health labs across the country.

"We have quickly selected these institutions after training and evaluation programs held on Feb. 7 and 20," official Park Hyun Kyu at Korea's Center for Disease Control told ABC News. "They do preliminary screening, then send all positively sampled results to us for final diagnosis."

Dr. Todd Ellerin, Director of Infectious Disease at South Shore Health in Massachusetts, says the massive number of tests is impressive.

"I think it’s excellent," said Ellerin, who confirmed the validity of the South Korean tests. "It’s an urgent situation right now, and that’s how we should be adjusting."

Doctors from around the world agree.

"Impressive testing going on here. All hail these labs!" Ian M. Mackay, a virologist at Australia's University of Queensland, tweeted.

"I definitely respect their earnestness and transparency," tweeted Dr. Eric Feigl-Ding, an epidemiologist at Boston's Harvard Chan School of Public Health.

"Very detailed COVID-19 reporting ... demonstrating a significant diagnostic capability," tweeted Dr. Scott Gottlieb of Washington, D.C.'s American Enterprise Institute.

A big reason for South Korea's success is how quickly they were able to get test kits ready, Ellerin said.

"One thing China did was that [after] the first case came in November, activity began in late December and by January 10th China shared the sequence with the public and they already had test kits on that day."

Officials say the rapid implementation was possible because the South Korean government was able to shorten the process for the newly developed test kits to be approved by its version of the Food and Drug Administration.

"It would normally take about a year to get a test kit approved, but FDA gave out emergency approval to acceptable applicants on a temporary basis," Park told ABC News.

For the testing itself, medical institutions, spread out across local communities, follow detailed instructions provided by the central health authorities and screen applicants with suspicious respiratory symptoms. The meticulous process takes from half an hour to an hour per person.

"It just takes a lot of time because the tester has to change suits to a new one every time," said Park.

"All medical teams dispose of their quarantine suits and inspection tools by using it just once, and new medical tools are used for each patient, every time," an official with Samsung Medical Center, one of the largest testing centers in Seoul, told ABC News.

As number of tests continues to stack up, several locations have set up "drive-thru" centers that could minimize contact between the potential patient and medical staff. This new idea shortens time spent on testing to just 10 minutes per person since the medics do not have to change quarantine suits for every patient.

Applicants must drive to the site in their privately owned vehicles wearing masks. Tests are conducted at a makeshift tent outside of buildings to prevent spreading indoors.

"When I got there, someone opened the car door for me," Koo Ji-young told ABC News after receiving his test results for a $140 fee. "First, they take a chest X-ray, then measure body temperature using a noncontact measuring device. A doctor stuck a long stick into my nose and made me spit phlegm."

The government has called for more volunteer nurses and doctors to help meet the rising demand for tests.

"As of [Wednesday] morning, 205 people have registered to volunteer. We still need more," Health Vice Minister Kim Gang-lip said during a media briefing.

In Daegu, where 80 percent of all confirmed cases have been reported, 28,000 residents who have reported symptoms of flu or cold will be tested by the end of the month, officials said. Authorities have also pledged to test more than 200,000 followers of a secretive sect at the center of the recent outbreak.

Ellerin, the infectious disease director, said the massive amount of testing also creates valuable data.

"This is a contagious respiratory virus," said Ellerin. "For instance, during flu season, roughly ten percent get affected. With South Korea's 55 million population, you could easily imagine 5 million getting this."

"Sometimes we tend to overestimate," he said. "So let's see where this leads to."

ABC News' Hakyung Kate Lee, Heejin Kang and Jiyung Koo contributed to this report.