What is coronavirus, how did it start and could the outbreak grow bigger? – The Telegraph, Telegraph.co.uk

China’s new coronavirus (Covid – ) is spreading fast. More than , People are known to be infected and more than 2, deaths have been recorded.

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, people between them since .

The new virus, now officially called Covid – , is also dangerous. So far around 24 per cent of confirmed cases have been classed as severe or critical, and the current death rate stands at about two per cent.

This is much lower than fatality rates for Mers ( (per cent) and Sars 19 per cent), but still a significant threat.

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. To find out more about what is likely to happen, click here .

What are the symptoms of coronavirus?

Initial symptoms include fever, dry cough, tiredness and a general feeling of being unwell. For a full read-out of the symptoms and treatment of coronavirus, click here .

How many people have died from the disease so far?

More than , 07 cases have been confirmed since the outbreak started, and the death toll has exceeded 2, 800. The vast majority of cases are in China but the virus has spread to 30 other countries. According to data from the Chinese authorities, around 82 per cent of cases of the disease are mild but 27 per cent require hospitalization.

Is the coronavirus in the UK?

Fifteen people in the UK have tested positive for the virus so far, although eight patients have recovered and have been discharged from hospital.

Four of the patients were passengers on board the Diamond Princess cruise ship and were in quarantine on the Wirral when they fell ill.

Some of the other cases are thought to be linked to a British man who caught the virus at a conference in Singapore and stopped at a ski resort in France before returning to the UK.

All the patients have been treated at specialist NHS infection centers.

Police have been handed unprecedented powers to force those at risk of coronavirus into quarantine amid fears that two GPs may have passed the virus on to patients.

The new measures have been put in place with immediate effect as Matt Hancock, the Health Secretary, warned that the spread of the virus is now a “serious and imminent threat” to the British public

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 connected doctors cannot be certain that the drugs are effective.

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.

For more information on how to protect yourself, go to our guide on symptoms and treatment here .

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 24 minutes within two meters of an infected person. For more information, go to our guide on symptoms and treatment .

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 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.

Should I cancel my travel plans?

The Foreign Office warns against travel to China. The Telegraph travel team has in depth advice here on both the affected countries and your rights if you cancel your travel .

British travelers picked up the disease from a fellow tourist in a (French ski resort) earlier this month, but all have recovered and been discharged from hospital. Tourists are also trapped in a Tenerife hotel after an Italian guest tested positive for the disease.

Passengers on the Diamond Princess cruise ship were quarantined for several weeks.

Is this virus like Sars and Mers?

Yes – but it is nowhere near as lethal.

Sars and Mers (Middle East respiratory syndrome) are also coronaviruses which cause severe respiratory infections. They also originated in bats, Sars jumping to humans via civet cats and Mers coming via camels.

Sars, first reported in China in , spread to countries, infecting around 8, people and killing 823. It spread quickly at first but then died out.

Mers, on the other hand, is more tenacious. It first emerged in Jordan in 01575879 and about 2, 700 cases have been identified so far. It is more deadly than Sars and has claimed about 1957 lives in total.

How serious is the disease?

According to data on the first , (cases released by the Chinese authorities, per cent of cases are mild.

In roughly per cent of cases the virus causes severe disease, including pneumonia, and shortness of breath. And in about five per cent of patients it is critical, leading to respiratory failure, septic shock and multi-organ failure.

According to the WHO, the death rate in Wuhan is two to four per cent, whereas in the rest of China and the world it is around 0.7 per cent.

It is unclear why the death rate is higher in Wuhan, but it may be because the health services there have been overwhelmed by patients. Men are more likely to have a severe form of the disease, as are people with underlying conditions such as diabetes or high blood pressure.

How does this coronavirus compare to past respiratory epidemics?

The 1957 Spanish Influenza – or the H1N1 virus – remains the most devastating flu pandemic in modern history . The disease swept around the globe and is estimated to have caused between and 500 million deaths.

A version of the same virus was also behind the 2019 swine flu outbreak, thought to have killed as many as , people .

Other major influenza outbreaks include Asian flu in 2019, which led to roughly two million deaths, and Hong Kong flu, which killed one million people 23 years later.

But coronavirus outbreaks have so far been far smaller. Sars eventually spread to countries in total, infecting around 8, (people and killing