The bulk of cases and fatalities have been confined to China, but the virus is spreading internationally.
What is a coronavirus?
Coronaviruses are a family of viruses that cause disease in animals. Seven, including the new virus, have made the jump to humans, but most just cause cold-like symptoms.
Two other coronaviruses – Middle East respiratory syndrome (Mers) and severe acute respiratory syndrome (Sars) – are much more severe, having killed more than 1,500 people between them since 2002.
The new virus, officially called Covid-19, is also dangerous. So far, around 20 per cent of confirmed cases have been classed as severe or critical, and the death rate stands at around two per cent.
This is much lower than fatality rates for Mers (30 per cent) and Sars (10 per cent), but still a significant threat.
Scientists in China believe that Covid-19 has mutated into two strains, one more aggressive than the other, which could make developing a vaccine more complicated.
How did the outbreak start?
The source of the coronavirus is believed to be a "wet market" in Wuhan which sold both dead and live animals including fish and birds.
Such markets pose a heightened risk of viruses jumping from animals to humans because hygiene standards are difficult to maintain if live animals are being kept and butchered on site. Typically, they are also densely packed.
The animal source of the latest outbreak has not yet been identified, but the original host is thought to be bats. Bats were not sold at the Wuhan market but may have infected live chickens or other animals sold there.
Bats are host to a wide range of zoonotic viruses including Ebola, HIV and rabies.
Could the outbreak grow bigger?
It is impossible to say which way the disease will go but, on its current trajectory, it is likely to spread to more countries, affecting many more people. The number of cases is beginning to decrease in China but is climbing in the rest of the world.
What are the symptoms of coronavirus?
Initial symptoms include fever, dry cough, tiredness and a general feeling of being unwell.
How many people have died from the disease so far?
More than 96,000 cases have been confirmed since the outbreak started, and the death toll has exceeded 3,300. The vast majority of cases are in China, but the virus has spread to more than 80 other countries. According to data from the Chinese authorities, around 80 per cent of cases of the disease are mild, but 20 per cent require hospitalisation.
Is coronavirus in the UK?
115 people in the UK have tested positive for the virus so far, although eight patients have recovered and been discharged from hospital.
Is there a cure for the coronavirus?
There is no specific treatment, although doctors are trialling existing drugs for viruses such as Ebola and HIV. Early results seem promising but, until full clinical trials have been concluded, doctors cannot be certain that the drugs are effective.
Work to develop a vaccine is accelerating, but this work has been complicated by the virus mutating into a second strain.
How is coronavirus spread?
Like cold and flu bugs, the virus is spread via droplets when a person coughs or sneezes. The droplets land on surfaces and are picked up on the hands of others and spread further. People catch the virus when they touch their infected hands to their mouth, nose or eyes.
It follows that the single most important thing you can do to protect yourself is keep your hands clean by washing them frequently with soap and water or a hand sanitising gel.
Is the coronavirus airborne?
There is some debate about whether the disease is airborne – there is no evidence for it yet, but that could change. Airborne viruses linger for a longer period of time than those spread by droplets and can also be spread in air conditioning and ventilation systems.
The current advice is that the disease can only be spread between close contacts – defined as spending more than 15 minutes within two metres of an infected person.
Who started the coronavirus?
Various crazy conspiracy theories have been circulating that the virus somehow escaped from a Chinese lab, either by accident or design. However, this is categorically untrue and scientists studying its genetic code have linked it to bats. It probably then jumped to another animal, which passed it on to humans.
The number of diseases crossing from animals to humans is growing, and teams of virus hunters are tracking them down.
Where is the disease now?
As well as being reported in China, the disease is now in more than 80 countries around the world, including popular south-east Asian holiday destinations such as Thailand, Vietnam, Singapore and Malaysia.
Italy has also seen a large number of cases, leading the authorities to impose a lockdown in the north of the country.
The disease has also spread to the Middle East, with Iran particularly affected.