By James Gallagher

A virus causing severe lung disease that started in China has spread to 27 other countries, including the UK.

The coronavirus had infected 77,234 people in China as of February 24, with 2,594 of them dying.

What are the symptoms?

It seems to start with a fever, followed by a dry cough. After a week, it leads to shortness of breath. The infection rarely seems to cause a runny nose or sneezing.

The incubation period – between infection and showing any symptoms – lasts up to 14 days, according to the World Health Organisation (WHO).

But some researchers say it may be as long as 24 days.

And Chinese scientists say some people may be infectious even before symptoms appear.

How deadly is the virus?

Based on data from 44,000 patients with coronavirus, the WHO says: 81 per cent develop mild symptoms,14 per cent develop severe symptoms, five per cent become critically ill.

The proportion dying from the disease, which has been named Covid-19, appears low (between one and two per cent) – but the figures are unreliable. 

Thousands are still being treated but may go on to die – so the death rate could be higher. To put this into context, about one billion people catch influenza every year, with between 290,000 and 650,000 deaths. The severity of flu changes every year.

Can coronavirus be treated or cured?

Right now, treatment relies on the basics – keeping the patient’s body going, including breathing support, until their immune system can fight off the virus.

However, work to develop a vaccine is under way. Hospitals are also testing anti-viral drugs to see if they have an impact.

How can I protect myself?

The WHO says: Wash your hands – soap or hand gel can kill the virus.

Cover your mouth and nose when coughing or sneezing – ideally with a tissue – and wash your hands afterwards, to prevent the virus spreading.

Avoid touching your eyes, nose and mouth – if your hands touch a surface contaminated by the virus, this could transfer it into your body

Don’t get too close to people coughing, sneezing or with a fever – they can propel small droplets containing the virus into the air.

How fast is it spreading?

Thousands of new cases are being reported each day. However, analysts believe the true scale could be 10 times larger than official figures.

Outbreaks have now occurred in South Korea, Italy and Iran, raising fears that it could become a pandemic. 

A pandemic is declared when an infectious disease threatens different parts of the world simultaneously.

How did it start?

This virus is not really “new”  it is just new to humans, having jumped from one species to another. 

Many of the early cases were linked to the South China Seafood Wholesale Market, in Wuhan.