Experts say source of newly identified virus in China must be found

By Sally Robertson, B.Sc.Jan 9 2020

Chinese state media reported today that scientists have identified the virus that is likely to have caused the pneumonia-like illness seen in dozens of people recently in the central city of Wuhan.

Image Credit: Kateryna Kon / Shutterstock.com

After identifying a new form of coronavirus (the family that Sars belongs to), scientists have now sequenced its genome, and fifteen people have tested positive for the virus.

The first cases were reported last week

The first cases of the illness were reported last week in Wuhan, and, on Sunday, neighboring Hong Kong announced more suspected cases as people returning from Wuhan were found to have fever and respiratory symptoms. In Wuhan, where almost 60 people were affected, the virus was linked to a seafood market, where wild animals, including pheasants and snakes, were also sold. The market has since been closed for disinfection.

The outbreak, which prompted authorities to quarantine affected individuals, led to online speculation about a resurgence of the Sars (severe acute respiratory syndrome) virus, which killed 349 people in mainland China and 299 in Hong Kong, following an outbreak in 2003.

However, Leo Poon, a virologist and Sars expert at the University of Hong Kong, said that since the unidentified virus had not yet caused any deaths, there was no reason to believe that the outbreak would become more serious.

Medical authorities in Wuhan also ruled out Sars, Middle East respiratory syndrome (Mers), and avian influenza as possible causes of the outbreak and the Wuhan health bureau had said there was no evidence so far of human-to-human transmission.

The situation this week

Since these assurances, no deaths have been reported in Wuhan, and eight patients who were no longer showing symptoms of pneumonia were discharged from hospital by Wednesday. The Wuhan health authority also reports there is still no evidence of human-to-human transmission.

Now, a top official at the Chinese Center for Disease Control and Prevention (CDC) has announced to the state news agency Xinhua, that his research group has identified the pathogen as a new form of coronavirus and that fifteen patients in Wuhan have tested positive for the virus. Citing a task force of medical experts, state broadcaster China Central Television, also reported the discovery earlier today.

Xu Jianguo, director of the CDC’s National Institute for Communicable Disease Control and Prevention, says that now the cause of these unexplained cases of viral pneumonia has been identified as a new type of coronavirus, this initial finding needs to be followed up with further research.

“A notable achievement”

Experts have praised the rapid identification of the new strain of virus, but they agree that more research is needed to understand it.

China’s World Health Organisation (WHO) representative for China, Gauden Galea, described the initial identification of the new coronavirus in such a short period of time as “a notable achievement” that would help authorities in other countries to detect and respond to outbreaks.

However, he called for more detailed information to understand what caused the outbreak and how it should be managed in the coming weeks: “Further investigations are also required to determine the source, modes of transmission, extent of infection and countermeasures implemented.”

About the coronavirus family

Coronaviruses cause varying degrees of illness, ranging from the common cold to the deadly Sars. Four of the six previously known human coronaviruses are common and only cause minor respiratory symptoms, but the other two (Sars and Mers) are more dangerous and have claimed hundreds of lives worldwide.

As well as infecting humans, coronaviruses can infect mammals such as cats, dogs, pigs, cattle, camels, bats, and mice. The WHO says that the Sars virus probably infected humans after jumping from animals.

What’s next?

Galea says the WHO is continuing to monitor the situation closely and will readily provide technical support to China to investigate and respond to the outbreak.

Respiratory medicine expert at the Chinese University of Hong Kong, David Hui Shu-Cheong, says a number of important details still needed to be established.

“Some key information, including which animal is the source of the virus, the incubation period and the transmission route, is still missing.”

David Hui Shu-Cheong, Chinese University of Hong Kong