A Korean Air flight traveling to Las Vegas was diverted to Los Angeles International Airport on Wednesday due to concerns that some of its passengers had been exposed to the coronavirus, according to a statement from the airline.

The flight continued to McCarran International Airport in Las Vegas once they passed screening tests.

Three of the flight's 200 passengers had reportedly been in China within 14 days of the flight's departure. After showing no signs of symptoms in Los Angeles, they were allowed back on the flight.

FLIGHT ARRIVES IN CALIFORNIA FROM EPICENTER OF CORONAVIRUS OUTBREAK, 178 PASSENGERS WILL BE QUARANTINED

It wasn't clear if they had been to Wuhan -- the epicenter of the coronavirus outbreak.

Disinfection equipment is carried by a worker as precautionary measures against the spreading of novel coronavirus, at Budapest Liszt Ferenc International Airport in Budapest, Hungary, Wednesday, Feb. 5, 2020. So far almost 900 passenger arriving directly from China have been examined at the airport. (Zoltan Balogh/MTI via AP)

Disinfection equipment is carried by a worker as precautionary measures against the spreading of novel coronavirus, at Budapest Liszt Ferenc International Airport in Budapest, Hungary, Wednesday, Feb. 5, 2020. So far almost 900 passenger arriving directly from China have been examined at the airport. (Zoltan Balogh/MTI via AP)

A spokesman from McCarran confirmed reports there were “concerns that passengers aboard had been to China.”

There are now 12 confirmed cases of the virus in the U.S.

As of Wednesday night, six were in California, one in Wisconsin, one in Arizona, one in Washington state, one in Massachusetts and two in Illinois. No deaths have been reported in the U.S., and 99 percent of cases still remain in China.

One person was announced to have been infected in Wisconsin on Wednesday after being exposed to the virus while in China, according to the Wisconsin Department of Health Services.

“DHS is operating with an abundance of caution and is working very closely with the local health department and UW Hospital and Clinics to ensure that this patient and any close contacts are closely monitored,” said State Health Officer Jeanne Ayers. “The risk of getting sick from 2019 novel coronavirus in Wisconsin is very low. We are responding aggressively to the situation and monitoring all developments. We are committed to keeping the public fully informed and will continue to provide updates as this situation unfolds.”

HONG KONG AIRLINE ASKS WORKERS TO TAKE THREE-WEEK UNPAID LEAVE IN MIDST OF CORONAVIRUS

UW Health says they are operating with "an abundance of caution" to make sure the patient is "closely monitored."

The Huoshenshan temporary field hospital under construction is seen as it nears completion in Wuhan in central China's Hubei Province, Sunday, Feb. 2, 2020. (Chinatopix via AP)

The Huoshenshan temporary field hospital under construction is seen as it nears completion in Wuhan in central China's Hubei Province, Sunday, Feb. 2, 2020. (Chinatopix via AP)

“Since initial treatment at University Hospital, the patient has been self-quarantined at home. We are coordinating with the CDC, DHS, and local health authorities," said UW Health Medical Director of Infection Control Dr. Nasia Safdar.

The U.S. announced on Sunday that Americans who traveled to China within the last 14 days would be sent to designated airports for enhanced screenings. Foreign nationals who recently went to China would be denied entry in the U.S., except for the immediate family of American citizens and permanent residents.

In Asia, 20 passengers have tested positive for the coronavirus aboard one of two quarantined cruise ships outside of Japan, according to health officials in the country on Thursday.

Cruise ship Diamond Princess is anchored off the shore of Yokohama, south of Tokyo, Wednesday, Feb. 5, 2020. Japan said Wednesday 10 people on the cruise ship have tested positive for a new virus and were being taken to hospitals. Health Minister Nobukatsu Kato said all the 3,700 people and passengers on the ship will be quarantined on board for up to 14 days under Japanese law. (Hiroko Harima/Kyodo News via AP)

Cruise ship Diamond Princess is anchored off the shore of Yokohama, south of Tokyo, Wednesday, Feb. 5, 2020. Japan said Wednesday 10 people on the cruise ship have tested positive for a new virus and were being taken to hospitals. Health Minister Nobukatsu Kato said all the 3,700 people and passengers on the ship will be quarantined on board for up to 14 days under Japanese law. (Hiroko Harima/Kyodo News via AP)

Yesterday, 10 people aboard the Diamond Princess ship had fallen ill with the virus, resulting in roughly 3,700 passengers being placed in quarantine -- a total of 5,000 on both ships.

OVER 5,000 PASSENGERS ON 2 CRUISE SHIPS QUARANTINED AS CORONAVIRUS WORLDWIDE DEATH TOLL NEARS 500

Medical workers in protective suits lead a passenger tested positive for a new coronavirus from the cruise ship Diamond Princess at Yokohama Port in Yokohama, south of Tokyo, Wednesday, Feb. 5, 2020.. (Hiroko Harima/Kyodo News via AP)

Medical workers in protective suits lead a passenger tested positive for a new coronavirus from the cruise ship Diamond Princess at Yokohama Port in Yokohama, south of Tokyo, Wednesday, Feb. 5, 2020.. (Hiroko Harima/Kyodo News via AP)

Two additional people in New York City are also being tested for the coronavirus after returning from China.

“New York City is on high alert and prepared to handle any confirmed cases of the novel coronavirus,” said Mayor Bill de Blasio in a statement. “My message to New Yorkers remains the same: if you have the travel history and are exhibiting symptoms, please see your health provider immediately.”

Earlier this week, testing for one of the previous three people in New York City come back negative for the coronavirus after they made recent trips to mainland China, according to the state's Department of Public Health.

WISCONSIN CONFIRMS CASE OF CORONAVIRUS IN PATIENT WHO TRAVELED TO CHINA

“The first person who met the criteria to have samples sent to the Centers for Disease Control and Prevention (CDC) was found not to have the 2019 novel coronavirus,” said Health Commissioner Dr. Oxiris Barbot. “The response and care the patient received reflects how well the systems we have in place are working. We want to thank everyone for all they did, and we will keep New Yorkers informed as the situation develops.”

Results of the pending four tests should be known in 36-48 hours, officials said.

China's Foreign Ministry said on Monday that the U.S. hasn't given the country any substantive help in its fight against the coronavirus outbreak. They added the U.S. was contributing to the international panic surrounding the illness, according to a report by Reuters.

Medical staff strike over coronavirus concerns outside government headquarters in Hong Kong on Wednesday. In Hong Kong, hospitals workers are striking to demand the border with mainland China be shut completely to ward off the virus, but four new cases without known travel to the mainland indicate the illness is spreading locally in the territory.(AP Photo/Vincent Yu)

Medical staff strike over coronavirus concerns outside government headquarters in Hong Kong on Wednesday. In Hong Kong, hospitals workers are striking to demand the border with mainland China be shut completely to ward off the virus, but four new cases without known travel to the mainland indicate the illness is spreading locally in the territory.(AP Photo/Vincent Yu)

Weeks after China announced the outbreak of the coronavirus, the international community has increased measures to prevent a widespread epidemic.

The World Health Organization (WHO) declared the outbreak a global emergency as it spreads to countries outside of China and the number of infected patients continues to grow.

Countries around the globe have increased travel restrictions to the infected mainland China and Hubei province — with the U.S. State Department increasing its advisory to level 4: "Do Not Travel."

STATE DEPARTMENT, CITING CORONAVIRUS OUTBREAK, RAISES CHINA TRAVEL ADVISORY: 'DO NOT TRAVEL'

U.S. Centers for Disease Control and Prevention (CDC) have advised travelers to avoid all nonessential travel to the country.

A man wearing a face mask stands on a subway train in Beijing, Monday, Feb. 3, 2020. Much of China officially went back to work on Monday after the Lunar New Year holiday was extended several days by the government due to a virus outbreak, but China's capital remained largely empty as local officials strongly encouraged non-essential businesses to remain closed or work from home. (AP Photo/Mark Schiefelbein)

A man wearing a face mask stands on a subway train in Beijing, Monday, Feb. 3, 2020. Much of China officially went back to work on Monday after the Lunar New Year holiday was extended several days by the government due to a virus outbreak, but China's capital remained largely empty as local officials strongly encouraged non-essential businesses to remain closed or work from home. (AP Photo/Mark Schiefelbein)

Coronavirus has now infected and killed more people in China than were sickened during the SARS outbreak in the early 2000s.

The SARS outbreak had killed 349 people in mainland China back in 2002 and 2003 -- with 744 deaths and 8,096 infections globally, according to the CDC.

Here are the latest figures.

How many have been infected or have died?

The death toll from the virus increased to 563 on Thursday, with over 28,200 infected around the globe.

HONG KONG RAMPS UP CORONAVIRUS FIGHT BY QUARANTINING VISITORS FROM MAINLAND CHINA

The first death outside of China was recorded in the Philippines on Sunday. The 44-year-old Chinese man from Wuhan was hospitalized last week with a fever, cough and sore throat, and died after developing severe pneumonia, according to the Philippines health department.

Hong Kong reported its first death on Tuesday in a 39-year-old man who traveled from Wuhan. Hong Kong currently has 21 cases of the virus, while Macao has 10.

The WHO said the number of cases will keep growing as tests are pending on thousands of suspected cases.

Where is the virus?

Roughly 99 percent of new cases have appeared in China with the vast majority of the cases in Hubei province and its provincial capital, Wuhan -- the epicenter of the virus.

A volunteer stands in front of a Communist Party flag as he takes the temperature of a scooter driver at a roadside checkpoint in Hangzhou in eastern China's Zhejiang Province, Monday, Feb. 3, 2020. China sent medical workers and equipment to a newly built hospital, infused cash into financial markets and further restricted people's movement in sweeping new steps Monday to contain a rapidly spreading virus and its escalating impact. (Chinatopix via AP)

A volunteer stands in front of a Communist Party flag as he takes the temperature of a scooter driver at a roadside checkpoint in Hangzhou in eastern China's Zhejiang Province, Monday, Feb. 3, 2020. China sent medical workers and equipment to a newly built hospital, infused cash into financial markets and further restricted people's movement in sweeping new steps Monday to contain a rapidly spreading virus and its escalating impact. (Chinatopix via AP)

About 225 cases have been reported in at least 25 countries globally.

The United Kingdom announced last Friday it has two cases of the virus, who are reportedly members of the same family.

CORONAVIRUS TESTING KITS TO BE SENT TO LABS ACROSS US TO SPEED UP DIAGNOSES: FDA

"The patients are receiving specialist NHS [National Health Service] care, and we are using tried and tested infection control procedures to prevent further spread of the virus," said Chris Whitty, England's Chief Medical Officer.

Japan -- 45

Singapore -- 28

Thailand -- 25

South Korea -- 23

Australia -- 14

Germany -- 12

Taiwan -- 11

Malaysia -- 10

France -- 6

United Arab Emirates -- 5

Canada -- 4

India -- 3

Phillippines -- 3 (1 death)

Russia -- 2

Spain -- 1

Italy -- 2

Sweden -- 1

Belgium -- 1

Nepal -- 1

Finland --1

Sri Lanka -- 1

Cambodia -- 1

Differences between coronavirus and the flu?

The flu has estimated to have killed roughly 10,000 to 25,000 people with nearly 19 to 26 million infected in the U.S. between October 1, 2019, and January 25, 2020, according to the CDC. Coronavirus has impacted a far lesser number, although it's not yet clear how many have been infected or how widespread it is.

There have also been reports it can be spread without symptoms showing up. In respiratory illnesses, people with the most symptoms are the most contagious, the agency said. Children and those over 65 are the most likely to get sick from the flu, the CDC added.

HOW IS CORONAVIRUS TRANSMITTED?

Unlike the coronavirus, there's a seasonal vaccine for the flu. People over six months out are advised by the agency to get it during annual vaccination, with certain rare exceptions, such as severe allergies to the shot.

A masked shopper walks in the Chinatown district of San Francisco on Friday, Jan. 31, 2020. As China grapples with the growing coronavirus outbreak, Chinese people in California are encountering a cultural disconnect as they brace for a possible spread of the virus in their adopted homeland. (AP Photo/Ben Margot)

A masked shopper walks in the Chinatown district of San Francisco on Friday, Jan. 31, 2020. As China grapples with the growing coronavirus outbreak, Chinese people in California are encountering a cultural disconnect as they brace for a possible spread of the virus in their adopted homeland. (AP Photo/Ben Margot)

No vaccine has been developed for coronavirus as of yet, which makes it dangerous in that respect.

How did it start?

It's not entirely clear how it started, but Chinese scientists believe the virus may have originated in bats. A study by the Wuhan Institute of Virology said that genome sequences from seven patients tested were identical to the bat coronavirus.

How does it transmit?

It's believed the normal coronavirus can be transmitted most commonly through respiratory droplets in the air, as well as close contact with an infected person or touching areas contaminated with the virus before washing. The digestive tract may also transmit the disease, according to scientists from the Renmin Hospital of Wuhan University and the Wuhan Institute of Virology of the Chinses Academy of Science.

HOW IS CORONAVIRUS TRANSMITTED?

They recently discovered "virus genetic material" in feces samples and rectal swabs from some patients, Chinese state media reported.

What are the current travel restrictions?

The U.S. declared the coronavirus a public health emergency last Friday with Trump signing an order barring entry to foreign nationals who recently were in China, other than the immediate family of American citizens and permanent residents.

CHINA SLAMS TRUMP'S CORONAVIRUS TRAVEL LIMITS: 'NOT A GESTURE OF GOODWILL'

Officials at the CDC have advised travelers to avoid all nonessential travel to the country. The U.S. State Department raised its China travel advisory to "Level 4: Do Not Travel." The U.S. expanded the screening of travelers arriving from Wuhan from five to 20 airports.

People wearing face masks ride a mostly empty subway train during the morning rush hour in Beijing, Monday, Feb. 3, 2020.  (AP Photo/Mark Schiefelbein)

People wearing face masks ride a mostly empty subway train during the morning rush hour in Beijing, Monday, Feb. 3, 2020.  (AP Photo/Mark Schiefelbein)

"Those currently in China should consider departing using commercial means. The Department of State has requested that all non-essential U.S. government personnel defer travel to China in light of the novel coronavirus," The advisory said.

Vietnam stopped all flights to and from China.

Japan, Singapore, Indonesia, New Zealand, and Australia all have similar policies to the U.S. on restricting non-citizens.

Mongolia and Singapore have shut their borders.

Singapore said it would ban travelers from China's Hubei province.

AIRLINE PASSENGER ARRESTED OVER FALSE CORONAVIRUS CLAIM SAYS HE DID IT FOR 'PUBLICITY'

Pakistan says they're halting all flights to and from China until Feb. 2.

The United Kingdom and New Zealand advised their people against nonessential travel to China.

Russia has signed an order to close the border between them and China. They also blocked tour groups from China.

China has cut off access to Wuhan, the epicenter of the outbreak, trapping more than 50 million people

Hong Kong quarantining visitors from mainland China

MORE AMERICANS TO BE EVACUATED FROM CHINA AMID CORONAVIRUS OUTBREAK: OFFICIALS

Japan bars foreign nationals who had been to Hubei province.

Carnival and Royal Carribean denying boarding of people who travel to China within 14 days.

Italy suspended all flights to China.

UNITED AIRLINES SUSPENDS ALL FLIGHTS TO HONG KONG AMID CORONAVIRUS OUTBREAK

South Korea urged an increase in its level of caution to "restraint" when traveling to China.

Hong Kong reduced half its flights and shut down rail service to mainland China.

Cathay Pacific Airways asks 27,000 employees to take three weeks of unpaid leave.

Cathay Pacific Airways is asking 27,000 of its workers to take three weeks of unpaid leave as the company deals with the economic impact of the coronavirus.

Cathay Pacific Airways is asking 27,000 of its workers to take three weeks of unpaid leave as the company deals with the economic impact of the coronavirus. (Cathay Pacific Airways)

Delta suspended all service to China

United Airlines suspends all flights between China and the U.S.

United's pilots, concerned for their safety, were able to drop trips to China without pay, a union memo said, according to Reuters.

American Airlines suspends all flights to China.

The Allied Pilots Association (APA), which represents 15,000 pilots for American Airlines filed a lawsuit to halt service with the airline, citing “serious, and in many ways still unknown, health threats posed by the coronavirus."

"I am directing all APA pilots to cease flight operations between the United States and China," said APA president Eric Ferguson. "Until further notice, if you are scheduled, assigned, or reassigned a pairing into China, decline the assignment by calling your Chief Pilot or IOC Duty Pilot. Inform them you are declining in accordance with the CDC and WHO declarations."

AMERICAN AIRLINES SUED OVER CORONAVIRUS BY PLOT SEEKING TO CANCEL US-CHINA FLIGHTS

British Airways suspended all flights to and from mainland China.

Virgin Atlantic suspending operations to Shanghai for two weeks.

Lufthansa suspending flights to and from China

Air India and Seoul Air halting all flights to the country.

Egypt Air suspended all fights starting Feb. 1.

Air France suspending all flights

Finnair, Cathay Pacific, and Jetstar also stopping service.

Lion Air canceled 50 flights to China into February.

Air Canada suspending all direct flights to Beijing and Shanghai.

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Kenya Airways suspends all flights to China.

The Associated Press contributed to the report