The new coronavirus that originated in China and spread to dozens of countries around the world has prompted a warning from health officials for Americans to prepare for the possibility of a domestic outbreak.
So far, there are only a handful of cases in the U.S., but tens of thousands of people have been infected worldwide — most of them in China — and more than 2,000 people have died as a result of the virus.
It causes an illness called COVID-19 (the name is an abbreviation for COronaVirus DIsease 2019).
You might be wondering: What are the symptoms? How can I protect myself? And how do people get the virus?
Here are some answers to those questions and more:
How deadly is the virus?
Researchers in China recently found a fatality rate of 2.3% among confirmed COVID-19 cases in mainland China. According to findings published by the China Centers for Disease Control and Prevention, 1,023 of the 44,672 confirmed cases in the study resulted in death.
However, fatality rates depend on factors like the patients' medical care and are difficult to estimate early in an outbreak.
"If you're in the U.S., the estimates are the death rate is going to be way less than 1%," said CBS News medical contributor Dr. David Agus.
"We have excellent supportive care here in the United States," he said, and there are drugs in clinical trials that "look like they're effective," though they haven't been fully tested yet.
Agus also noted that in China, "they're only testing people who are really sick. So when you look at a death rate where you're not counting most people who have the virus, the death rate is obviously going to be artificially much higher," he explained.
The Chinese study offered insight into the demographics of some of those who have died. The majority of those deaths were among people age 60 and older and/or people who had "pre-existing, comorbid conditions" such as high blood pressure, cardiovascular disease and diabetes.
"Preliminary data suggest that older adults and persons with underlying health conditions or compromised immune systems might be at greater risk for severe illness from this virus," the CDC says, citing the data.
Men also had a higher death rate than women — 2.8% for males and for 1.7% females, according to the Chinese study.
The researchers analyzed 72,314 patient records, including confirmed, suspected and clinically diagnosed coronavirus cases. They found the illness was "mild" for 81% of patients.
For reasons that are not yet totally clear, children appear to be less susceptible to the virus. The Chinese researchers found that children accounted for less than 1,000 of the 44,672 confirmed cases they cited in their study.
How can you get coronavirus?
It is believed the new virus originated last year in a food market that sold exotic animals in the Chinese city of Wuhan, the epicenter of the global outbreak. It is now believed the virus spreads mainly from person to person, the CDC says.
That can happen through infected droplets from a cough or sneeze when people come into close contact with each other — within about 6 feet — although officials say it's unclear how easily the virus is transmitted.
"It may be possible that a person can get COVID-19 by touching a surface or object that has the virus on it and then touching their own mouth, nose, or possibly their eyes, but this is not thought to be the main way the virus spreads," the CDC says.
This week, officials confirmed the first possible instance in the U.S. of "community transmission" — a case where the infection's source is unknown, not from travel or known contact with another patient. That person is hospitalized in California.
What are the symptoms?
"Common signs of infection include respiratory symptoms, fever, cough, shortness of breath and breathing difficulties," the World Health Organization says.
"In more severe cases, infection can cause pneumonia, severe acute respiratory syndrome, kidney failure and even death."
The CDC says symptoms can appear in as little as two days or as long as two weeks after initial exposure.
When is someone contagious?
The CDC says infected people are thought to be most contagious when they're sickest. But it might be possible to spread the virus even before someone has symptoms.
"For two weeks, people may not have any symptoms at all, and during those two weeks they can spread the virus," said Dr. Agus.
How can you protect yourself?
Health officials recommend washing your hands frequently, and for at least 20 seconds. Hand sanitizers with at least 60% alcohol can also be used.
CDC officials recommend:
Officials say the risk for Americans remains low and do not recommend that people wear face masks unless they are sick or are caring for someone who is sick.
Is there a vaccine for coronavirus?
Health officials estimate it will be at least a year or a year and a half before a vaccine could become available to the public.