Previously unknown virus may be causing pneumonia outbreak in China, WHO says

A cluster of more than 50 pneumonia cases in China's central Wuhan city may be due to a newly emerging member of the family of viruses that caused the deadly SARS and MERS outbreaks, the World Health Organization (WHO) has said.

While the United Nations health agency said it needed more comprehensive information to confirm precisely the cause of the infections, it said a new coronavirus was a possibility.

China's official Xinhua news agency said on Thursday that preliminary lab results conducted by a team of experts showed the pathogen was a new type of coronavirus.

Fifty-nine cases of the pneumonia had been reported as of Sunday.

Coronaviruses are a large family of viruses that can cause infections ranging from the common cold to Severe Acute Respiratory Syndrome (SARS). Some of the virus types cause less serious disease, while some — like the one that causes Middle East Respiratory Syndrome (MERS) — are far more severe.

"Chinese investigators conducted gene sequencing of the virus, using an isolate from one positive patient sample," Dr. Gauden Galea, WHO Representative to China, said in a statement on Thursday. He commended the preliminary identification of a new virus as a demonstration of "China's increased capacity to manage new outbreaks."

The outbreak comes ahead of the Lunar New Year holidays in late January, when many of China's 1.4 billion people will be traveling to their home towns or abroad. The Chinese government expects passengers to make 440 million trips via rail and another 79 million trips via airplanes, officials told a briefing on Thursday.

The WHO statement said that, according to Chinese authorities, the virus behind the Wuhan cases can cause severe illness in some patients but does not appear to pass easily from person to person.

Jeremy Farrar, a specialist in infectious disease epidemics and director of British-based global health charity the Wellcome Trust, said that while "a cluster of patients with an unusual respiratory infection is, and should always be, a worry... if the infection is not passing person to person, the level of concern is somewhat reduced."

Wang Yang, the Chinese transport ministry's chief engineer, told the briefing that authorities will step up efforts to prevent the pneumonia outbreak from spreading further during the holiday period, including ensuring proper disinfection in major public transportation hubs.

The Canadian government's travel health notice for pneumonia of unknown cause in China recommends travellers to Wuhan: 

• Avoid high-risk areas such as farms, live animal markets, and areas where animals may be slaughtered.
• Avoid contact with animals (alive or dead), including pigs, chickens, ducks and wild birds.
• Avoid surfaces with animal droppings or secretions on them.

Travellers are also advised to take precautions against respiratory and other illnesses, such as handwashing and cough and sneeze etiquette. 

The WHO noted that coronaviruses emerge periodically — including in 2002 to cause SARS and in 2012 to cause MERS — and said more information was required to confirm the pathogen and understand the epidemiology of the outbreak and its progress.

In 2003, Chinese officials covered up a SARS outbreak for weeks before a growing death toll and rumors forced the government to reveal the epidemic. The disease spread rapidly to other cities and countries. More than 8,000 people were infected and 775 died.