There are now 37,200 cases worldwide, with 813 deaths. As of 9 February, four people in the UK have tested positive for the virus.
The virus in this outbreak is one of seven in the coronavirus family, although it has never been seen before in humans. First discovered in the mid-1960s, coronaviruses were named for their crown-like shape and are zoonotic (they can be transmitted from animals to humans).
Both the outbreak of SARS (Severe Acute Respiratory Syndrome) in 2003 and various MERS epidemics (Middle Eastern Respiratory Syndrome) were caused by coronaviruses.
This strain, given the intermediary name 2019-nCoV (2019 novel coronavirus), is suspected to have originated in bats, given its similarity to bat coronaviruses. There is also suspicion that it entered human populations through an animal in the Huanan Seafood Wholesale Market in Wuhan.
Coronavirus causes respiratory symptoms similar to that of a cold, but develops into viral pneumonia if it spreads into the lower respiratory tract.
One of the reasons coronavirus is hard to treat is because it is a virus, so antibiotics are of no use. There is currently no vaccine or drug to fight the virus, so members of the population with weakened immune systems, such as the elderly, young children, and people with long-term health conditions such as cancer and diabetes are most at risk.
The incubation period for the virus can be anywhere from 2-14 days, meaning people could be infected (and infecting others) for up to two weeks before they start showing symptoms.
However, the current death toll suggests a 3% mortality rate, not much higher than that of flu. This is only an estimate and the actual number could be even lower due to infected people only having mild symptoms.
Most healthy people should be able to fight the virus off, and the majority of deaths in China have been due to pre-existing health conditions that were exacerbated once the virus took hold.