After a sudden jump in the number of deaths caused by the new coronavirus in China, we are learning about the disease, its spread and how it is localized.
The official death toll in China rose sharply on Thursday after authorities changed their counting methods.
While fears that the epidemic is actually much more dangerous than reported, the new technique uses lung imaging and could help diagnose faster.
To date, more than 60,000 people have been infected, the vast majority in China's Hubei province, the epicenter of the outbreak.
A total of 1,370 people are known to have died from the virus, all but three in China.
Calculating the mortality rate of a new virus strain is difficult due to the time lag between reported cases and confirmed deaths.
In one study from the Imperial College this week, the death rate in Hubei province was 18 percent.
However, globally, the study estimates that mortality is much lower, ranging from 0.5 to 4.0 percent of cases.
If confirmed, it is likely that the new coronavirus is less deadly than other strains such as SARS and MERS, with mortality rates of 9.5% and 34.5%, respectively.
How contagious is the coronavirus?
According to a study by Chinese scientists in the New England Medical Journal, everyone who gets the coronavirus infects an average of 2.2 people.
This is higher than winter flu (1.3), lower than infectious disease such as measles (over 12), and comparable to SARS (3), the last virus to break out in China in 2002-03.
WHO chief Tedros Adhanom Ghebreyesus said the key question is how quickly the disease spreads outside China.
'Finding a small number of cases may indicate more widespread transmission in other countries; in short, we can only see the tip of the iceberg, 'he warned in his last tweet.
A study this week, which has yet to be peer-reviewed, showed that the epidemic in Wuhan – the city at the center of the outbreak – is likely to peak in mid-February.
When is it possible to get infected?
Scientists speculated that the virus began to spread a few days after symptoms appeared, Arnaud Fontanet of the Pasteur Institute told AFP.
Now they think it might have passed on earlier.
“Today everyone agrees that the infectious period begins as soon as symptoms appear,” says Fontanet, an emerging disease tracking specialist.
He even added that there have been several cases of transmission from people who did not have symptoms.
One of the reasons these cases are rare is that cough is the primary means of transmission and the asymptomatic carrier does not cough.
What are the symptoms of coronavirus?
A study of 99 coronavirus patients published last month concluded that roughly half of the cases occurred in people with underlying chronic conditions such as heart disease and diabetes.
All patients had pneumonia, most had a fever, 80 percent had a cough, and more than half had difficulty breathing.
Identifying the symptoms of the coronavirus is even more important – and difficult – due to the simultaneous seasonal flu epidemic that has similar symptoms.
Where did the coronavirus come from?
Many animals are capable of transmitting viruses to other species, and almost all strains of coronavirus infectious to humans come from the wild.
Bats are known to carry the latter strain of the disease, but scientists believe the virus was spread to humans in Wuhan through another species of mammals.
Chinese researchers last week suggested that the pangolin, a mammal, may be the 'missing link' that transmitted the disease to humans.
The official name of the virus, which belongs to the same family as SARS, is SARS-CoV-2, and the name of the disease it causes is COVID-19.
Agence France-Presse.
Sources: Photo: JUAN GAERTNER / SCIENCE PHOTO LIBRARY
