The outbreak of a virus originating in central China entered a new phase of severity as multiple medical workers were reported to have been infected and the death count grew to four people.
The spread to medical workers indicates that the illness is more easily transmitted than previously thought, bringing it to a higher risk level reminiscent of the SARS pandemic 17 years ago that killed 800 people.
As hundreds of millions of Chinese prepare to travel across the country and globally for the Lunar New Year, the latest developments are raising alarms that the novel coronavirus that originated in Wuhan will spread more rapidly.
"The risk from this virus causing pandemonium has increased because it is spreading from different countries, and we are now seeing that it can be more easily transmitted from person to person," said Sanjaya Senanayake, associate professor of medicine at the Australian National University. In comparison with SARS, he said, "the one good factor, I guess, at the moment seems to be the low mortality rate."
The World Health Organization confirmed that the new pathogen is being transmitted among humans, and not just from animals to humans as was originally hoped. Fifteen medical professionals have been affected, with one critically ill, according to a report from state news agency Xinhua.
The transmission of the virus to medical workers is particularly worrisome considering the heavy precautions that were taken in Wuhan to try to minimize infections among health-care staff. SARS also represented a high risk to health-care workers.
China's health commission has decided to include the coronavirus in the Class B infectious diseases category, which includes SARS, while taking preventive steps typically used for the most-serious ailments, such as cholera and plague, according to a notice posted on the website late Monday.
The source and transmission routes of the virus, known as 2019-nCoV, are still unknown. Some of the first group of patients in Wuhan worked or shopped at a seafood market where live animals and wildlife parts were also reportedly sold.
The coronavirus had been drawing comparisons with SARS since its discovery at the end of last year. That outbreak started with sporadic infections and gathered speed as it passed though Singapore's hospitals before spreading around the world, hurting companies and economies.
Coronaviruses are a large family of viruses, some causing illness in people, and others that circulate among animal, including camels, cats, and bats, the Centers for Disease Control and Prevention said. While rare, animal coronaviruses can evolve and infect people, and then spread between people.
While the rate of fatalities with the new virus is still comparatively low, health experts worry that the virus could mutate and become more deadly.
Health officials in Wuhan confirmed a fourth death on Tuesday. An 89-year-old male, who had a history of hypertension, diabetes and coronary heart disease, was hospitalized on Jan. 18 and died the following day.
Wuhan now has almost 200 confirmed cases. The number of cases in China surged over the weekend as health authorities worldwide increased testing for the virus, which includes symptoms like fever and coughing. Infections were reported in Beijing and the southern Chinese province of Guangdong, while South Korea, Thailand and Japan have also reported cases _ all related to travel from Wuhan.
Other countries are on alert, stepping up screening of incoming travelers. International airports in New York, Los Angeles and San Francisco started screening from late Friday, joining cities in Asia that implemented surveillance measure days after the outbreak was reported on Dec. 31.
"From a public health point of view, both at a national and international level, you have to assume the worst case scenario � so the SARS scenario � where you had cases going from Hong Kong to all over the world," said Senanayake.
The WHO convened a meeting of its emergency committee for Jan. 22 in Geneva, according to an emailed statement. Members will discuss "whether the outbreak constitutes a public health emergency of international concern, and what recommendations should be made to manage it."
