How Dangerous is the New Coronavirus?

The rapid spread of a new coronavirus in China has prompted global alarm, with Beijing’s neighbours closing their borders, global airlines suspending flights, and some governments even barring entry to foreign nationals who have recently been in China.

The rapidly spreading virus, first detected in the central Chinese city of Wuhan in late December, has infected more than 24,500 people and killed nearly 500. The vast majority of the victims have been in China, although the virus has now spread to two dozen countries.

In a bid to limit the spread of the virus to countries with weaker health systems, the World Health Organization (WHO) on January 30 declared the new viral outbreak a public health emergency of international concern. The global health agency, however, criticised the international travel curbs and flight suspensions on China, telling governments such measures must be “short in duration” and “proportionate”.

So how dangerous is the new coronavirus, and how worried should you be?

The simple answer is we don’t know enough yet and we won’t know until more data comes in.

But the key factors, according to experts, are how contagious the new virus is and what proportion of people become severely ill.

The new type of coronavirus, labelled 2019-nCoV and thought to have originated in a seafood market in Wuhan, is part of a family of viruses that include the common cold and severe acute respiratory syndrome (SARS). The new coronavirus spreads primarily through droplets when an infected person coughs or sneezes, and can also be spread via contaminated surfaces.

According to statistics from China, about two percent of people infected with the 2019-nCoV have died so far. For comparison, 10 percent of the 8,437 people infected with SARS during the 2002-2003 outbreak died, suggesting the new virus is less deadly. The Middle East respiratory syndrome (MERS), which originated in Saudi Arabia in 2012, has a fatality rate of about 35 percent.

World’s worst epidemics [Al Jazeera]

Seasonal influenza outbreaks, meanwhile, kill less than 0.1 percent of people who the flu virus infects, but as many as a billion people are estimated to fall ill with the common cold each year. The WHO estimates that between 290,000 and 650,000 people die every year from the common cold.

But it may be too early to estimate fatality rates for the new coronavirus epidemic as we are still in the early stages of the outbreak.

And unlike the common cold, the novel coronavirus has no vaccine and no specific medicine recommended to prevent or treat it.

Another key measure in judging the danger of the new virus is its transmissibility.

According to an analysis published by scientists at Harvard University in the United States on January 26, each infected person could pass on the new virus to up to three people. That makes the new coronavirus as contagious as SARS.

The WHO says it is people living or travelling in the area where the virus is circulating who may be at risk of infection. At present, the virus is circulating in China, and those infected from other countries are among people who have recently travelled from China or who have been living or working closely with those travellers. This suggests the risk to most people outside China remains low.

Additionally, the WHO, citing preliminary information, says the amount of time the virus survives on surfaces appears to be a few hours. “Simple disinfectants can kill the virus making it no longer possible to infect people,” the agency says.

And while there is still much more we need to learn about how the new coronavirus affects people, it is older people and people with pre-existing medical conditions who are more at risk of becoming severely ill, according to the WHO.

To avoid any viral illness, the global health agency recommends that people frequently wash their hands, cover their mouths and noses when sneezing or coughing, and avoid close contact with those who are sick.