More than 14,000 people have been infected by the new coronavirus, which continues to spread to more countries since it was first detected in the Chinese city of Wuhan in early December.
At least 304 people have died so far in China, and one in the Philippines. Almost all the fatalities in China have been in Hubei province, of which Wuhan is the capital.
How is the coronavirus spreading?
The 2019-nCoV coronavirus spreads from person to person in close proximity, similar to other respiratory illnesses, such as the flu.
The disease can be transmitted through sneezing or coughing, which disperses droplets of body fluids such as saliva or mucus.
According to scientists, coughs and sneezes can travel several feet and stay suspended in the air for up to 10 minutes.
These droplets can come into direct contact with other people, or can infect those who pick them up by touching surfaces on which the infected droplets land, or touching a surface and then their face.
It is not yet know how long the virus can survive on surfaces, but in other viruses, the range is between a few hours or months.
Transmission is of particular concern on transport, where droplets containing the coronavirus could pass between passengers or via surfaces like plane seats and armrests.
The incubation period of the coronavirus, the length of time before symptoms appear, is between one and 14 days.
Though not yet confirmed, Chinese health authorities believe the virus can be transmitted before symptoms appear.
This would have major implications for containment measures, according to Gerard Krause, head of the Department for Epidemiology at the Helmholtz Centre for Infection.
“It’s unusual for respiratory diseases transmissible even before the first symptoms have occurred,” he told Al Jazeera.
“But the consequences is that if it happens then they have no public health means sort out or to identify people at risk of transmitting, because they don’t even know that they’re ill yet.”
Can people be immune to the new coronavirus?
Viruses that spread quickly usually come with lower mortality rates and vice versa.
Although the total number of deaths has risen, the current death rate stands at about 2.4 percent – this is lower than first feared and well below severe acute respiratory syndrome, another coronavirus that broke out between 2002 and 2003, which killed 9.6 percent of those infected.
As the virus is an entirely new strain, there is no existing immunity in anyone it will encounter.
Some level of immunity will naturally develop over time, but this means that those with compromised immune systems, such as the elderly or sick, are most at risk of becoming severely ill or dying from the coronavirus.
How can people protect themselves? Are face masks useful?
In terms of self-protection and containing the virus, experts agree that is important to wash hands thoroughly with soap; cover your face when coughing or sneezing; visit a doctor if you have symptoms and avoid direct contact with live animals in affected areas.
While face masks are popular, scientists doubt their effectiveness against airborne viruses.
They may provide some protection to you and others, but they are loose and made of permeable material, meaning droplets can still pass through.
Some countries, such as the UK and Nigeria, have advised people travelling back from China to self-quarantine for at least two weeks.
What is being done to stop the coronavirus spread, and when will a vaccine become available?
China has placed Wuhan and more than a dozen other cities under lockdown, affecting more than 50 million people, although this has not prevented the virus from spreading to all of China’s provinces.