Coronavirus was declared a ‘public health emergency of international concern.’ What you need to know about the illness.

The World Health Organization declared Thursday that the outbreak of a novel coronavirus first identified in Wuhan, China, is a “public health emergency of international concern,” and, hours later, the U.S. State Department issued a “do not travel” advisory for China.

As of Friday morning, Chinese health officials had reported 9,692 confirmed cases of the virus, being referred to as the 2019 Novel Coronavirus or 2019-nCoV, which has spiked more than tenfold in a week, and 213 fatalities, up from the 170 reported Thursday morning. There have been no reported deaths outside of China, but officials around the world are working quickly to contain the fast-spreading illness, with an estimated 108 cases confirmed outside of China.

“Our greatest concern is the potential for the virus to spread to countries with weaker health systems and which are ill-prepared to deal with it,” WHO director-general Tedros Adhanom Ghebreyesus said during a Thursday press conference. “Let me be clear: This declaration is not a vote of no confidence in China. On the contrary, WHO continues to have confidence in China’s capacity to control the outbreak.”

The new designations came the same day that the U.S. reported its first case of a person-to-person spread of the illness, the husband of a Chicago woman, who became sick after she returned from a trip to the central Chinese city of Wuhan. Chinese officials have closed transportation in and out of the centrally located city and others in the surrounding Hubei province.

The U.S. Centers for Disease Control and Prevention is advising travelers to avoid all nonessential travel to China, and, earlier this week, hundreds of Americans were evacuated by the U.S. government from Wuhan, where the first illnesses appeared in December.

This week, Boston’s Logan International Airport was included in the more than a dozen U.S. airports identified by the CDC as screening passengers from China for the virus. Local health officials have organized response protocols, should a case of coronavirus be identified in the region. As of Friday morning, there had been no confirmed cases of the virus in the Northeast, with the closest confirmed cases in Chicago.

Below, what you need to know.

What is the coronavirus?

A health official scans the body temperature of a passenger as she arrives at Soekarno-Hatta International Airport in Tangerang, Indonesia.

The novel virus, 2019-nCoV, comes from the coronavirus family, which includes strains responsible for everything from the common cold to those that cause much more severe illnesses like severe acute respiratory syndrome (SARS).

But unlike the 2003 global outbreak of SARS, which also originated in China, officials were able to identify the new coronavirus rather quickly, within three to four weeks, according to Dr. David Hamer, an attending in infectious diseases at Boston Medical Center and professor of Global Health and Medicine at Boston University Schools of Public Health and Medicine.

“The good news is that this looks like it may be somewhat less severe overall,” he said, comparing what is known so far about the current illness to SARS. “But it’s a little early to define what the exact proportion of people dying is — the case fatality rate. But that said, there are a number of people that are getting either milder illness or getting sick and being hospitalized, but then are recovering. Really only a small proportion are severely ill and are dying.”

So far, it is thought that the novel coronavirus is spread person-to-person mainly through respiratory secretions — droplets produced when someone sneezes or coughs — similar to the flu. Reported symptoms include mild to severe fever, cough, and shortness of breath, and, in severe cases, pneumonia.

The CDC has cautioned that symptoms of the illness could appear in as few as two days, or as long as 14, after exposure.

“At this time, it’s unclear how easily or sustainably this virus is spreading between people,” the CDC says.

Treatment for the virus is supportive to try and help relieve symptoms — there is no specific antiviral medication for 2019-nCoV.

Hamer said so far it appears that the new coronavirus is a “moderately severe virus” — not as severe as SARS – and that most people appear to be recovering from it.

“We’ve seen in the initial cases that there seems to be a higher risk in older people, especially those over the age of 60, and individuals with underlying medical conditions,” he said.

How will people be screened at Logan?

According to the CDC, for the enhanced health screenings at designated airports, like Logan, travelers from China will be asked to fill out a questionnaire about their travel and any potential symptoms they are experiencing, along with their contact information.

“CDC staff take the temperature of each traveler with a hand-held non-contact thermometer (thermometers that do not touch the skin) and observe the traveler for cough or difficulty breathing,” the agency said. “If sick travelers are identified, CDC evaluates them further to determine whether they should be taken to a hospital for medical evaluation and to get care as needed.”

If a passenger doesn’t have any symptoms, they will still be provided with health information cards to take with them, describing the coronavirus and what they should do if they do develop symptoms within 14 days from their departure from China.

According to The Boston Globe, public health protocols were triggered when a “sick passenger” arrived at Logan on Wednesday afternoon. Boston EMS responded, but, upon evaluation, the traveler was determined to not meet the criteria for the coronavirus.

“All safety protocols are being followed,”  Massachusetts Port Authority spokeswoman Jennifer Mehigan told the Globe.

What are local officials saying about illness?

Passengers arrive at Heathrow Airport in London after the last British Airways flight from China touched down in the UK following a Wednesday announcement that the airline would be suspending all flights to and from mainland China immediately.

Right now, according to the CDC, the immediate health risk from the coronavirus to the general American public who are “unlikely to be exposed” to the virus is “considered low.”

“The goal of the ongoing U.S. public health response is to contain this outbreak and prevent sustained spread of 2019-nCoV in this country,” the CDC says.

A spokesperson for the Massachusetts Department of Public Health said Thursday the risk to Massachusetts residents is “currently low.”

DPH is working closely with the @CDCgov to monitor the novel #Coronavirus originating in Wuhan, China. To date, there are no MA cases and risk to residents is low. Latest info: https://t.co/HuT798OJaq pic.twitter.com/h86vYxjwyM

— Mass. Public Health (@MassDPH) January 30, 2020

The department is asking anyone who recently traveled to Wuhan to seek medical care “right away” if symptoms develop and to call ahead to your health care provider to inform them of your recent travel and symptoms. If you are experiencing symptoms, officials issued the following guidance:

Avoid contact with others. Stay home, except for seeking medical care.

Avoid further travel until the illness resolves.

Cover your mouth and nose with a tissue or your sleeve (not your hands) when coughing or sneezing.

Wash hands often with soap and warm water for at least 20 seconds. If unavailable, use an alcohol-based hand sanitizer.

“At this point I really don’t think people in Boston or the United States need to worry a lot,” Hamer said of local concerns about the novel virus. “There have been a few patients that have come in (to the U.S.) with the disease — the CDC has very rapidly scaled up airport based-screening through existing quarantine stations and then quarantine stations that have been reopened.”

The airports targeted for additional screening, like Logan, are those that are likely to have air traffic from China, he said.

Echoing WHO officials, Hamer, too, praised China’s response to the outbreak and the measures rapidly taken to contain the coronavirus.

“This is an unprecedented response to an outbreak,” he said. “I think the Chinese government in this case really should be commended. I think there were issues with how they responded initially to the SARS outbreak — this time, I think they’re doing a lot of things right.”

What steps should you be taking to protect yourself?

Chen Su, left, and Daniel Flash wear face masks at Los Angeles International Airport on Jan. 22, 2019, to protect against the Coronavirus.

Local officials are advising Boston area residents that the best prevention for the novel coronavirus are those that would be taken to safeguard against the current flu season (other than the vaccine) — washing your hands, covering your mouth and nose when you sneeze or cough, and staying home if you’re sick.

Those steps, as well as wearing a face mask if you are traveling by air are helpful measures, Hamer said. On a recent flight he took from Japan, he noted, many more passengers were utilizing the masks.

“I think that’s helpful,” he said.

Wearing a face mask, the doctor said, can serve as a barrier to the exposure of viruses. And, if worn by someone exhibiting respiratory symptoms, the mask can help reduce the spread of the virus through respiratory droplets.

“It is hard to define how much they serve to protect a healthy person,” Hamer said. “Elderly individuals and those with underlying medical conditions appear to be at higher risk for more severe coronavirus disease and potentially death so they might benefit from wearing masks to reduce their risk of exposure. Frequent hand washing is also critically important.”

To further protect yourself, Hamer advised heeding the CDC’s advisory of avoiding nonessential travel to China and even putting off travel to Southeast Asia for a few weeks as more is learned about the progression of the virus.

“The public health measures that have been taken by the CDC and the Massachusetts Department of Public Health really should reduce the risk of an outbreak developing in the Boston area,” he said.

Information from the Associated Press was used in this report.