What you need to know about coronavirus

Health authorities are closely watching an outbreak of respiratory illness caused by a new strain of coronavirus known as COVID-19. Here are the answers to key questions about the outbreak:

What is the new virus?

Scientists have identified the virus as a novel, or new, coronavirus. The name comes from the Latin word for crowns or halos, which coronaviruses resemble under a microscope. The coronavirus family has many strains that affect people. Some cause the common cold, while some originating in bats, camels and other animals have evolved into more severe illnesses such as SARS — severe acute respiratory syndrome — or MERS — Middle East respiratory syndrome.

Where did it come from?

The first cases of COVID-19 appeared in Wuhan, in central China’s Hubei province. Many of the first people infected had visited or worked at the Huanan Seafood Wholesale Market in Wuhan, which has since been closed for an investigation. Chinese health officials say they think the illness first spread from animals to people.

How widespread is it?

More than 156,000 cases of COVID-19 have been confirmed around the world, according to Johns Hopkins University. The majority of those cases are in China, but France, Germany, Iran, Italy, South Korea and Spain also have cases numbering in the thousands. In the United States, 2,951 cases have been confirmed.

How deadly is it?

More than 5,800 people have died from the virus, making the mortality rate about 3.7% among confirmed cases. By comparison, the mortality rate for the seasonal flu is generally about 0.1%. Experts say inconsistencies in reporting cases have made it difficult to precisely determine the mortality rate.

What are the symptoms?

Common symptoms include fever, dry cough and fatigue. Shortness of breath, chills and body aches are associated with more dangerous cases of coronavirus, according to the U.S. Centers for Disease Control and Prevention. In serious cases, the virus can cause pneumonia.

Is it worse than the flu?

Both diseases have similar symptoms and transmission methods, so they can be hard to tell apart. Experts have said that it’s a difficult question to answer: The coronavirus spreads more easily and appears to be deadlier. However, most cases of the virus are mild, while the flu causes more cases of serious illness.

How is it treated?

Testing can identify the virus, but there’s no vaccine to prevent an infection. Patients with the virus have been isolated in hospitals or homes to prevent spreading it. The symptoms are treated with pain and fever medication, and people are advised to drink plenty of liquids and rest while they recover.

How is it spreading?

Many coronaviruses can spread through coughing or sneezing, or by touching an infected person. Scientists believe the new virus can spread from person to person in close contact through the respiratory tract.

How long does the virus live on surfaces?

Tests by U.S. government and other scientists found that the new coronavirus can live in the air for several hours and on some surfaces — such as plastic and stainless steel — for as long as two to three days. Their work suggests people can get infected through the air as well as from touching things that were contaminated by others who have it, in addition to direct person-to-person contact.

Should you wear a mask?

Does hand sanitizer kill it?

Experts say frequent hand-washing with soap and water is the best way to prevent the spread of disease. Hands should be washed for at least 20 seconds after people sneeze, cough or use the restroom and before eating. If soap and water aren’t available, the CDC says hand sanitizer that contains at least 60% alcohol is an acceptable alternative.

Will warm weather slow down the disease?

Health experts note that some viruses, like the flu, peak during the winter and slow down during the summer. It’s possible that the spread of coronavirus may be stunted by warmer weather — droplets won’t stay in the air as long after people cough or sneeze, and people will spend less time indoors, where it’s easier for person-to-person spread to occur. But experts caution that because the virus is so new, there’s a lot we don’t yet know about it.

Can you get coronavirus twice?

Reports of people testing positive for the virus after recovering from COVID-19 have occurred in places like China and Japan.

There’s still a lot that’s unknown about the virus, but health experts told The New York Times that it was unlikely that people were getting re-infected after such a short period of time. Positive tests after recovering from the virus could be blamed on testing methods. One possibility is that the test used to detect coronavirus is highly sensitive and could be picking up very small amounts of the virus.

Other health experts have said that while people who recover may develop some immunity, it may not last long enough to prevent re-infection.

How many people have recovered from coronavirus?

According to data compiled by Johns Hopkins University, more than half of all patients infected with the new coronavirus have recovered.

The Associated Press and staff reports contributed to this report.

For more information about how Johns Hopkins University tracks coronavirus cases, visit the university’s blog post.