On Wednesday, the World Health Organization (WHO) issued a statement saying that Chinese authorities think that a new coronavirus is the cause behind the mysterious pneumonia cases in Wuhan, a city in Hubei Province.
There have been 59 reported cases so far, seven of which are in serious condition.
The coronavirus is linked to SARS and MERS.
How does the coronavirus spread?
"Coronaviruses are a large family of viruses that range from the common cold to SARS. Some cause less-severe disease, some more severe. Some transmit easily from person to person, while others don’t," said the WHO statement.
According to Chinese authorities, the virus can cause severe illness in some patients but does not appear to pass easily from person to person. https://t.co/iygrAN9033— CBC News (@CBCNews) January 10, 2020
The agency also said that the virus does not "transmit readily" from person to person, and can be the cause of critical illness in some people.
Previously, the Wuhan Municipal Health Authority had said that the disease had not spread from person to person, although experts say that this is an impossible claim to make at this early stage.
Symptoms of the coronavirus differ depending on its severity. In some people, it comes up as a common cold while in others it can lead to deadly results like were seen during the SARS outbreak in 2003.
Details of the mysterious illness in Wuhan
The first cases of pneumonia linked to the illness were recorded on December 30, 2019. Most of the cases in Wuhan are linked to one specific seafood market, with dealers and vendors being the primary patients.
In its preliminary statement on January 5, the WHO said that "The reported link to a wholesale fish and live animal market could indicate an exposure link to animals."
Protect yourself & reduce risk from #coronavirus infection:— World Health Organization (WHO) (@WHO) January 9, 2020
🤧Cover mouth & nose when coughing & sneezing
🥩Thoroughly cook meat & eggs
🌡Avoid close contact with anyone with respiratory illness
❌ Avoid close contact with wild or live farm animals pic.twitter.com/PVvMsPSMnU
Investigators are still currently tracking the source of the illness.
The WHO also praised the Chinese response time and efficiency as they wrote: "Preliminary identification of a novel virus in a short period of time is a notable achievement and demonstrates China's increased capacity to manage new outbreaks."