Southwest Airlines has removed a passenger from a flight amid concerns over coronavirus because they had recently traveled to Beijing and was displaying 'flu-like symptoms'.

The virus can cause fever, coughing, wheezing and pneumonia. It is a member of the Coronavirus family that's a close cousin to the deadly SARS and MERS viruses that have caused outbreaks in the past.

The sick passenger had completed the journey from Las Vegas but was escorted off the plane once it landed at Baltimore/Washington International Thurgood Marshall Airport Saturday afternoon.

In a video from a fellow passenger, a health official is heard explaining the action was 'because of this heightened time, we are just using an abundance of caution'.

Southwest Airlines removed a passenger from a flight amid concerns over coronavirus because they had recently traveled to Beijing and was displaying 'flu-like symptoms'

The passenger had already been screened and cleared in Nevada and in Mexico.

Fellow passengers were seen wearing masks over their mouths while seated on the flight.

In a blog post, passenger John Richardson said he had noticed a number of Chinese tourists wearing paper surgical masks when he arrived at the boarding gate in Vegas but 'didn’t think too much about it'.

'About an hour and a half into the flight I noticed the flight attendants checking on a passenger many rows in front of me. I didn’t think much about it,' Richardson explained online. 'Then they started passing out paper surgical masks along with alcohol wipes to those around that passenger. They later offered them to anyone who wanted them.'

The blogger suggested the passenger was male as he continued: 'After about 20-30 minutes, health officials escorted the passenger and his wife off the plane.'

Richardson added that the head of the BWI Emergency Department announced there was a very small chance that it was Coronavirus and passengers 'would be notified by Southwest if the passenger tested positive'.

The passenger who witnessed the commotion added that 'paramedics squirted our hands with hand sanitizer' as they deplaned.

Southwest confirmed in a statement that local medical personnel met Flight 2889 once it arrived 'due to reports of an ill Customer'.

'In light of the recent concerns of the coronavirus, our Crew followed recommendations from the Centers for Disease Control for responding to concerns to ensure the Customer, and those traveling with them, receive the assistance or support they may need,' the airline stated.

The Maryland Department of Health said in a statement that the person 'did not meet the Centers for Disease Control and Prevention criteria for 2019 novel coronavirus testing' but was referred to a medical facility for evaluation to determine whether additional follow-up was necessary.

After an evaluation by medical personnel, it was determined that no special action was indicated for anyone on the flight.

The person was released.

The sick passenger had completed the journey from Las Vegas but was escorted off the plane once it landed at Baltimore/Washington International Thurgood Marshall Airport Saturday

The blogger added in response to hearing there was no risk: 'I’m very glad that they took it seriously and didn’t just slough it off.'

Health officials in Los Angeles County on Sunday confirmed a fourth U.S. case of the new pneumonia-like virus from China.

The Los Angeles County Department of Public Health said Sunday the infected person presented themselves for care once they noticed that they were not feeling well and is currently receiving medical attention.

The person is a returning traveler from Wuhan City, China. The case came on the heels of confirmed cases in Orange County, California, Washington state and Chicago.

The Centers for Disease Control (CDC) confirmed the Orange County, California case.

The person was also a traveler from the Chinese city of Wuhan - the epicenter of the outbreak - and tested positive for the virus, the Orange County Health Care Agency announced late Saturday. The patient is in isolation at a hospital and in good condition.

The cases in California came on the heels of diagnoses in Washington state, on January 21, and Chicago, on January 24. Both patients - in Washington, a man in his 30s, and in Chicago, a woman in her 60s - had also traveled to China.

The CDC expects more Americans to be diagnosed with the newly discovered virus, which is believed to have an incubation period of about two weeks, as worldwide the number of confirmed cases nears 2,000.

The CDC is screening passengers on direct and connecting flights from Wuhan at five major airports in Atlanta, Chicago, New York City, San Francisco and Los Angeles.

Guidance from the CDC advises that people who have had casual contact with the patient are at 'minimal risk' for developing infection.