LONDON (BLOOMBERG) - The coronavirus disease spreading around the world has killed more than 810 people, exceeding the toll from the global outbreak of Sars that started in China almost two decades ago.
Less than two months after surfacing in late December in Wuhan, China, cases of the coronavirus have topped 37,000. The fast-spreading disease long ago eclipsed the 8,100 total cases of Sars, which was transmitted worldwide in eight months, disrupting travel, industry and health care, and killing 774 people before coming under control.
Both severe acute respiratory syndrome, or Sars, and the coronavirus are members of a larger family known to cause disease ranging from common colds to lethal infections. While both emerged from China before spreading to multiple countries, their paths have diverged in a number of significant ways.
The rate of deaths among people infected with Sars was close to 10 per cent, said David Heymann, who oversaw the World Health Organization's (WHO) response to the outbreak, while it appears that rate in coronavirus will be below 2 per cent. An analysis of about 17,000 coronavirus patients showed that 82 per cent had mild cases, WHO officials said in a press briefing.
"You have to compare the two in perspective," Heymann said in an interview. The coronavirus outbreak "could look more dramatic than it is."
The number of cases and deaths from the new coronavirus may be far higher. The health system in Wuhan has been overwhelmed by the disease, with limited ability to care for every patient or diagnose new cases. Other cases may have been too mild to be counted by Chinese officials.
"I'm taking them for their word, but I really can't guarantee that they're reporting the right number. The only way you can guarantee it is if you go there and you monitor them," said Anthony S. Fauci, head of the US National Institute of Health's National Institute of Allergy and Infectious Diseases. US officials have been trying to get a team into China to better study the outbreak.
The epidemic of Sars began in 2002 with a report of mysterious pneumonia in southern China's province of Guangdong. It shifted into a higher gear when it was amplified in hospitals and then, carried by international travellers, spread to 26 countries.
Hospital workers were at particularly high risk, as so-called super-spreading events sickened multiple doctors and nurses. The outbreak was finally controlled by July 2003 with improved infection-control procedures and the WHO's recommendations to limit travel to areas where the outbreak was still out of control.
While Sars infected and killed hundreds of people outside China, the newer virus, known as 2019-nCoV, has been mostly confined to the mainland, with all but two of the known fatalities there. Even as China has been lauded for its quick action and open communication regarding the outbreak, a number of unknowns continue to heighten concern about the disease.
"When you don't know your enemy, the fear of your enemy grows," said Michael Ryan, executive director of WHO's emergencies programme, said on Friday at a press conference.
Researchers still don't know exactly how the virus is spread. All signs point to droplet transmission, which means that small bits of fluid from the mouth and nose that carry the disease move from one person to the next, usually in face-to-face encounters.
There's some evidence that people who aren't experiencing symptoms - coughing, sneezing, muscle pain - can also spread the virus. That means airport screeners, as well as patients themselves, stand little chance of finding infected people. Some researchers also think the disease might be spread through contaminated faeces, which was also the case with Sars and presents other prevention challenges.
The severity of the coronavirus outbreak led to a lockdown of Wuhan city and Hubei province - with more than 58 million people - along with some other areas of China. The nation has become a virtual island as an increasing number of governments and airlines impose restrictions on travel from the mainland.
The WHO hasn't recommended travel limits related to the coronavirus, but countries are desperately trying to keep the illness from their shores. Research on the new virus is moving quickly, and more may be known soon about how the disease spreads and how to stop it, Heymann said. "There are already fewer and fewer unknowns," he said.