DALLAS — This story has been updated with information about a third suspected case in Texas.
Scientists have identified it as a new kind of coronavirus.
The virus is believed to have originated from a seafood market in the central city of Wuhan, China.
On Tuesday, the first U.S. case of the 2019 novel coronavirus (2019-nCoV) was confirmed. A second case was confirmed in Chicago on Friday.
The location of the third patient is not being released at this time, according to the Texas Department of State Health Services.
A department spokesperson released the following statement Friday evening:
"We’ve had four people Texas who meet the testing criteria due to their travel history and respiratory symptoms. One has tested negative and is not a case. Testing is ongoing for the other three. We won’t provide additional details unless there is a positive result."
The CDC said it believes the risk of the Wuhan coronavirus to the American public at large remains low.
But with all the recent headlines, there are a number of common questions that have come up.
We talked with GMA's Dr. Jennifer Ashton about what people need to know about the 2019 novel coronavirus.
What is coronavirus?
Coronaviruses have been around since the 1960s. Most of the time they infect animals, but some strains definitely infect humans. They cause mild common cold symptoms. Occasionally they cause pneumonia.
Why is this strain of coronavirus a public health concern?
This is a new or novel strain, so we don’t really know how it behaves. It’s already demonstrated that it’s changing or evolving, spreading from animals to humans, and now humans to humans.
SARS and MERS, which came with high mortality rates in 2002 and 2012, also in the same coronavirus family.
So far, 2019-nCoV appears less dangerous and infectious than SARS. That illness also started in China and killed about 800 people.
Will the flu shot protect you?
No, the flu vaccine is only effective against influenza.
What are the symptoms of this strain?
The symptoms of this coronavirus strain are difficult to differentiate from any other upper respiratory infection. They include fever, cough, some chest pain and difficulty breathing.
The most distinguishing factor right now in the U.S. is travel to China, in particular to Wuhan, in the last two weeks. The travel history is very important to tracking this virus.
Anyone who recently traveled to Wuhan and is showing symptoms of 2019-nCoV should stay at home and avoid any contact with other people unless seeking medical attention, the CDC said. Anyone showing symptoms seeking medical care should call the doctor's office or emergency room before arriving and tell them about your symptoms and recent travel.
What precautions should people to prevent contracting coronavirus?
Common sense precautions include washing your hands often, not touching your face, nose or mouth, avoiding sick people, and staying home if you are sick.
More from WFAA:
- CDC: Second US case of Wuhan coronavirus confirmed
- China confirms 1st death outside epicenter of coronavirus outbreak; expands lockdowns to 25 million
- China coronavirus not a global health emergency yet, WHO says
- VERIFY: Fact-checking viral coronavirus videos and claims
- First US case of China coronavirus confirmed in Washington State