A new strain of coronavirus (officially named 2019-nCoV), which has caused respiratory diseases in China, and spread to at least 23 other countries, has been declared a Public Health Emergency of International Concern (PHEIC) by the World Health Organization (WHO). Here are the basic facts you need to know about the virus (figures correct as of February 3 2020).

According to WHO reports, at least 361 people have died from the novel coronavirus, which first appeared in the Chinese city of Wuhan in December 2019. More than 17,200 cases have been confirmed in China, and experts say they expect the numbers to rise in the coming weeks.

Although the vast majority of cases have been in China, the virus, which can cause pneumonia, is worrying global health authorities. Some 151 cases have been confirmed in 23 countries, and the first death outside of China was recorded in the Philippines. Most of those affected by the virus had travelled from Wuhan, the epicentre of the outbreak.

This is only the fifth time that the World Health Organization has declared a public health emergency of international concern.

What is a public health emergency of international concern?

A public health emergency of international concern is declared by the WHO in cases of “an extraordinary event” which constitutes “a public health risk to other States through the international spread of disease” and potentially requires a coordinated international response”.

This definition implies a situation that is “serious, unusual or unexpected; carries implications for public health beyond the affected State’s national border; and may require immediate international action”.

Speaking at a meeting of the WHO Executive Board on Monday, the agency’s chief, Tedros Gebreyesus, explained that the decision to announce a PHEIC was made because of signs of human-to-human transmission outside China, and WHO’s concern regarding what might happen if the virus were to spread in a country with a weaker health system.

International solidarity, preparedness, not panic

Mr. Ghebreyesus also noted the importance of containing the virus in China: “if we invest in fighting at the source, then the spread to other countries is minimal and also slow. If it’s minimal and slow, what is going outside can also be controlled easily. It can get even worse. But if we give it our best, the outcome could be even better”.

Several countries have already put travel restrictions in place, but Mr. Ghebreyesus pointed out that WHO is not recommending measures that “unnecessarily interfere with travel and commerce”.

The WHO chief called on all countries to implement decisions that are “evidence-based and consistent”, support nations with weaker health care systems, accelerate the development of effective vaccines, and “invest in preparedness, not panic”.

With the virus now present in some 23 countries, international solidarity is of utmost importance, said Mr. Tedros, because “we are all in this together, and we can only stop it together”.

What is a coronavirus?

Coronaviruses consist of a core of genetic material, enclosed within an envelope of protein spikes, which resembles a crown (or, in Latin, corona). They are a large group of viruses that cause respiratory diseases and, sometimes gastrointestinal symptoms.

Diseases can range from the common cold to pneumonia, which can be fatal. In most people symptoms are mild, but some types can cause severe disease.

These include severe acute respiratory syndrome (SARS), first discovered in China in 2003, or Middle East respiratory syndrome (MERS), which originated in Saudi Arabia in 2012. MERS caused more than 2,400 cases and 850 deaths, and more than 800 people were killed by SARS.

It has been estimated that 20 per cent of patients infected with the novel coronavirus 2019-nCoV have severe symptoms. People who have other health problems (such as asthma, diabetes and cardiovascular disease) are particularly vulnerable.

How deadly is novel coronavirus?

As of Monday February 3, 361 people had died from novel coronavirus (2019-nCoV). This represents about 2 per cent of cases. By comparison, around 25 per cent of MERS cases resulted in the death of the patient.

However, at this stage it is still too early to determine how deadly the virus is: thousands of patients are being tested, with around 2,110 in a serious condition, and it is not yet known how these cases will evolve.

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