China ‘must find source’ after identifying Wuhan pneumonia as new virus from Sars family
- New strain is found in 15 of the patients from Wuhan
- Experts urge need for further investigation after some of the 59 people reported infected were traced to a seafood market
A top official at the Chinese Centre for Disease Control and Prevention (CDC) told state news agency Xinhua on Thursday that laboratory tests had identified the new virus and the whole genome sequence had been obtained.
Fifteen patients in Wuhan, Hubei province, had tested positive for the virus, which showed “typical coronavirus morphology”, according to Xu Jianguo, director of the CDC’s National Institute for Communicable Disease Control and Prevention, who headed a group of experts to identify the illness.
“The pathogen of these unexplained cases of viral pneumonia was initially identified as a new type of coronavirus,” he said, adding that initial identification needed to be followed up with further research.
Coronaviruses are a family of viruses that cause diseases varying in severity from the common cold to the deadly severe acute respiratory syndrome (Sars). Of the six previously known human coronaviruses, four were common and caused only minor respiratory symptoms similar to those of a cold. The other two are Sars, which killed more than 700 people worldwide after originating in China, and Middle East respiratory syndrome (Mers), which has killed more than 850 around the world since 2012.
Dr Gauden Galea, the World Health Organisation (WHO) representative to China, described the preliminary identification of the new coronavirus in a short period of time as “a notable achievement” that would help authorities in other countries to detect and respond to outbreaks.
But he called for more comprehensive information to understand what triggered the outbreak and how to manage it in the coming weeks.
“Further investigations are also required to determine the source, modes of transmission, extent of infection and countermeasures implemented,” Galea said.
He said the WHO would continue to monitor the situation closely and was ready to provide technical support to China to investigate and respond to the outbreak.
Lu Hongzhou, an epidemiologist at the Shanghai Public Health Clinical Centre, which helped to identify the coronavirus, said that although scientists were on alert for any mutations, the public had no cause to panic.
“The virus appears not to be highly pathogenic or contagious. There have been no fatalities and no cases of medical staff becoming infected,” he said.
But identifying the virus was only the first step and a huge amount of work was still needed to trace its source, he said.
“The CDC has been working on it and any cases that are related to the Wuhan outbreak will be reported,” Lu said.
Professor David Hui Shu-cheong, a respiratory medicine expert from the Chinese University of Hong Kong, said a number of important details 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,” he said.
Medical authorities in Wuhan had earlier ruled out Sars, Mers and bird flu as causes of the outbreak.
Sars killed hundreds of people in mainland China and Hong Kong, but no deaths have been reported in Wuhan and eight patients, no longer showing pneumonia symptoms, had been discharged from hospital by Wednesday. The Wuhan health authority has said that no human-to-human transmission has so far been detected.
There have been 59 reported cases of the mystery virus in Wuhan since last month, many of them involving individuals who worked in a seafood market where wild animals such as pheasants and snakes, as well as rabbit organs, had also been sold. The market has since been closed.
Dr Ho Pak-leung, an infectious disease expert from the University of Hong Kong, said that one area of focus for the investigation should be the supply chain of animals sold in the market, because coronaviruses carried by mammals and some birds could mix, mutate and jump from animals to humans.
If the virus came from that supply chain, animals carrying the coronavirus could have reached other locations too, Ho said.
“It would be necessary to check the supply chain as soon as possible, and see whether similar [animals] were supplied in other wet markets outside Wuhan,” he said.
The health authority in Wuhan was still assessing the seafood market and tracing people who had been in close contact with those infected. The city’s first case was identified on December 12 and the latest on December 29.
CDC official Xu said the laboratory had used genomic sequencing, nucleic acid detection, virus isolation and other methods to analyse samples from patients.
Although it is possible to find evidence of a pathogen in a short period of time, it could take years to produce a vaccine.
The new virus’ identification came a day before Chinese people began travelling in their hundreds of millions for the Lunar New Year holiday, during which 3 billion journeys are expected to be made in about 40 days.
Neither the country’s civil aviation authority nor its railway authority has reported any unexplained pneumonia cases, but the transport authority said it would monitor the situation closely and take measures to contain any spread of the virus during the busy travelling season.
“The emergence of the epidemic may cause everyone to worry about travelling during the Spring Festival, especially in areas with concentrated passenger traffic,” Wang Yang, the Ministry of Transport’s chief engineer, said.
“Arrangements and deployments have been made to focus on disinfection monitoring and protection measures in areas with a large number of passengers, including transport hubs, passenger stations and cargo hub factories.”
Additional reporting by Linda Lew