Chinese authorities have identified a previously unknown type of coronavirus as the cause of a recent pneumonia outbreak in the city of Wuhan.
The current situation follows the severe acute respiratory syndrome-coronavirus (SARS-CoV) outbreak in 2002 and first detection of Middle East respiratory syndrome-coronavirus (MERS-CoV) in 2012.
The cluster of infections had raised fears of a potential epidemic after China said last week that the virus causing it was a previously unknown type but came from the same family of viruses that caused the SARS and MERS epidemics.
However, the World Health Organisation (WHO) said that the outbreak of pneumonia that killed one person in China and infected 40 others appears to be linked to a single seafood market in the central city of Wuhan and has not spread beyond there so far.
"From the information that we have it is possible that there is limited human-to-human transmission, potentially among families, but it is very clear right now that we have no sustained human-to-human transmission," said Maria Van Kerkhove, acting head of WHO's emerging diseases unit.
The WHO is however preparing for the possibility that there could be a wider outbreak, she told a Geneva news briefing. "It is still early days, we don't have a clear clinical picture."
Kind of common virus
Coronaviruses are a large family of viruses that can cause infections ranging from the common cold to SARS. Some of the virus types cause less serious disease, while some - like the one that causes MERS - are far more severe. Both MERS and SARS are types of coronaviruses.
It is a kind of common virus that causes an infection in your nose, sinuses, or upper throat. Most coronaviruses are not dangerous.
Coronaviruses were first identified in the 1960s, but the source of the viruses are still unknown. They get their name from their crown-like shape. Sometimes, but not often, a coronavirus can infect both animals and humans.
How is it spreading?
Most coronaviruses spread the same way other cold-causing viruses do, through infected people coughing and sneezing, by touching an infected person's hands or face, or by touching things such as doorknobs that infected people have touched.
Almost everyone gets a coronavirus infection at least once in their life, most likely as a child. In the United States, coronaviruses are more common in the fall and winter, but anyone can come down with a coronavirus infection any time.
How to confirm the type of disease?
You could get lab tests, including nose and throat cultures and blood work, to find out whether your cold was caused by a coronavirus, but there's no reason to. The test results wouldn't change how you treat your symptoms, which typically go away in a few days.
The symptoms of most coronaviruses are similar to any other upper-respiratory infection, including runny nose, coughing, sore throat, a general feeling of being unwell, and sometimes a fever. In most cases, you won't know whether you have a coronavirus or a different cold-causing virus, such as rhinovirus.
These illnesses usually only last for a short amount of time. But if a coronavirus infection spreads to the lower respiratory tract (your windpipe and your lungs), it can cause pneumonia, especially in older people, people with heart disease, or people with weakened immune systems.
What to do about coronavirus?
There is no vaccine for coronavirus. To help prevent coronavirus infection, do the same things you do to avoid the common cold:
• Wash your hands thoroughly with soap and warm water or with an alcohol-based hand sanitiser.
• Keep your hands and fingers away from your eyes, nose, and mouth.
• Avoid close contact with people who are infected.
Treat a coronavirus infection the same way you treat a cold:
• Get plenty of rest.
• Drink fluids.
• Take over-the-counter medicine for sore throat and fever (but don't give aspirin to children or teens).
• A humidifier or steamy shower can also help ease a sore and scratchy throat.
Even when coronavirus causes MERS or SARS in other countries, the kind of coronavirus infection common in the US isn't a serious threat for an otherwise healthy adult. If you get sick, treat your symptoms and contact a doctor if they get worse or don't go away.
Source: Centre for Disease Control and Prevention, World Health Organisation and WebMD