Two of three patients the Virginia Department of Health was investigating for possible novel coronavirus have tested negative, health officials announced Monday. Test results for a patient in Northern Virginia are expected later this week.

The three patients met the clinical and epidemiologic criteria for the virus that prompted China to put millions under quarantine, the Virginia Department of Health said Sunday. The two patients who tested negative are from central Virginia.

As new cases of the coronavirus are reported around the world, a doctor explains where the 2019 Novel Coronavirus comes from and what you can do to protect yourself from the outbreak.

The health department has not released more specific information about where the patients live, work or have traveled.

Specific details about the patients won't be released to protect their privacy, health officials say. Officials say they were working closely with the patients and those they've had close contact with recently.

Health officials in Virginia say that patients under investigation generally went to their doctor with specific symptoms and had traveled to China within 14 days of feeling ill. Samples were collected and sent to the Centers for Disease Control and Prevention for testing.

George Mason University's Student Health Services released a letter to students Sunday addressing reports that a student who had returned from China was showing symptoms similar to the virus.

"This information is being shared on social media and communicated within social and academic networks at Mason," the letter said.

The university confirmed the patient is a GMU student who does not live on campus and is self-isolating while awaiting test results.

"Because other Mason community members and residents of Northern Virginia may also have traveled to China recently, public health officials strongly encourage everyone to continue practicing good hygiene and general precautions to prevent the spread of all communicable diseases," the letter said.

Some students are wearing masks around campus.

“There’s students that have concerns about coming to school, whether they work around children or they have some sort of immunodeficiency,” students Shane Martin said.

But not everyone is concerned.

“I’m not that worried, honestly," senior Frank Lu said. "I think the campus will do it efficiently; I trust them.”

As of Sunday night, five cases have been confirmed around in the U.S.: One in Arizona, two in California, one in Chicago and one in Washington state.

Coronavirus causes mild to moderate illness similar to the common cold, the Virginia Department of Health says. Symptoms include fever, cough and trouble breathing, officials say.

Researchers are still learning much about the disease and how it affects people. It's unclear how easily it spreads, health officials say.

Chinese officials say 56 people have died and nearly 2,000 people have been infected in that country. The outbreak is centered in the region of Wuhan, which has been put on lockdown, News4 reported.

Earlier this week, an exchange program between students from Wuhan, China, and a school in Fairfax County was canceled "out of an abundance of caution" in light of the infectious outbreak. None of those students were thought to be ill, News4 reported.

Coronaviruses are a large family of viruses that can cause mild and moderate illnesses like the common cold or more severe respiratory infections, including SARS.

Researchers and doctors are now working to stop the spread of a new, or novel, strain, 2019-CoV. The Virginia Department of Health says that some people only had mild symptoms, while others suffered more serious illnesses or death.

Stay with News4 for more on this developing story.