Wuhan pneumonia: Chinese tourist in Thai case did not visit outbreak-linked market, while scientists say virus not likely to prove as deadly as Sars
The new virus behind recent pneumonia cases in Wuhan is unlikely to cause a widespread, deadly epidemic like Sars, scientists say, as revelations that a Chinese tourist in Thailand had not visited the market linked to the outbreak raised fears of a potential spread of the disease.
The woman, 61, who was confirmed by Thai authorities to have the new virus, had not visited the now-closed mainland seafood market associated with the outbreak, the Post learned on Tuesday.
The discovery raised fears that the woman, the first confirmed case outside China, could have caught the virus in Wuhan at other markets, which she was understood to have visited.
That came as Reuters quoted the World Health Organisation as saying there had been “limited” human-to-human transmission of the new coronavirus, but WHO spokesman Tarik Jasarevic told the Post in an email reply that “there has been no evidence” of such an occurrence.
Hong Kong’s Chief Executive Carrie Lam Cheng Yuet-ngor said an expert meeting would be held on Wednesday to discuss the latest development of the disease, upon the return of a team of local health officials who visited Wuhan to gain first-hand knowledge. The tourist, who travelled to Bangkok from the city in Hubei province, was found to have a fever on arrival at Suvarnabhumi Airport on January 8 and was hospitalised that day. She was confirmed on Sunday to have been infected with the new coronavirus strain, which has struck at least 41 people in Wuhan and killed one.
Dr Sopon Eamsiritavorn, from the Thai Ministry of Public Health’s Department of Disease Control, told the Post it appeared the woman’s infection was not related to the Huanan Seafood Wholesale Market, which Chinese authorities had linked to the Wuhan outbreak and had been closed since January 1.
“It seems there’s no relation with the market,” he said, when asked whether the patient had visited the outbreak site.
A source familiar with the details of the case said the woman did not visit the market.
“But she did visit other markets before going to Thailand,” the source said.
Detailed investigations into the case were in progress.
Hong Kong’s Centre for Health Protection said on Tuesday that it had been closely monitoring the case in Thailand.
Professor David Hui Shu-cheong, a respiratory medicine expert from Chinese University, had previously said that if the woman had not been to the seafood market, it would suggest that the virus had spread to other parts of Wuhan.
Details on investigations in Thailand could be found by following reports from officials there, Jasarevic said.
Between December 31 and Tuesday, Hong Kong had reported 71 suspected cases, with 60 of them cleared and discharged.
Meanwhile, scientists who have studied the genome of the virus behind the recent outbreak believe it is unlikely to cause a widespread, deadly epidemic like Sars. The unnamed virus has been identified as a new strain of coronavirus, the same family of viruses as severe acute respiratory syndrome.
Chinese scientists released the virus’s genome sequence to the public on Saturday, and researchers who analysed the sequence said it was a distant relative of Sars and therefore unlikely to be as deadly.
“The description given by the Chinese scientists is accurate. This virus is not SARS-CoV and not particularly close by many standards. Based on previous research … the virus is likely attenuated in terms of disease,” said Vineet Menachery, an assistant professor with the University of Texas Medical Branch’s department of microbiology and immunology in Galveston.
Menachery analysed the genome sequence and found it had only about 73 per cent similarity to Sars.
“In certain patients, older people or people with comorbidities, the virus may cause more damage, but is not nearly problematic as the epidemic SARS-CoV strain,” he added.
Ralph Baric, a coronavirus researcher at the University of North Carolina, Chapel Hill, came up with a similar conclusion after his team tried to replicate the virus in their laboratory based on the genetic code provided by Chinese scientists.
Of the four known Sars-related bat viruses capable of infecting humans, this one was the most distant from Sars itself, Baric told Science.
Baric also praised the speed of the response to the virus. “One of the things that’s sad is that the public doesn’t realise how incredibly competent the public health and the basic science community are at going from a newly discovered virus to a tremendous amount of capacity to trace and try to control its spread,” he told the journal.
Xu Jianguo, head of an evaluation committee advising the Chinese government on the emerging virus, also told Science in an interview published on Friday that no new patients had appeared since January 5. “It’s good news. People fear something like Sars in 2003, but this is a different case. The outbreak is limited,” he said.
There had been worries about the transparency of the Chinese government’s handling of the outbreak but now that concern had largely been dismissed, according to the Science report.
Dr Hu Ming, deputy director of the department of epidemiology and health statistics at Central South University in Changsha, said she had been following the situation in Wuhan closely and had not found any signs of a cover-up after the health authorities first announced the outbreak on December 31.
“There was lots of work to do. Sequencing, for instance, would take time. The data must be verified carefully before release. I believe they are following strict, professional procedures,” she said.
“We have learned a painful lesson from Sars.”
Feng Zijian, deputy director of the Chinese Centre for Disease Control and Prevention, told China Central Television on Tuesday that the genome sequence of the coronavirus had showed it was “neither Sars nor Mers” (Middle East respiratory syndrome) and the difference in their genome sequences was “very big”.
Sars infected more than 8,000 people, killing over 700 globally after originating in China in 2003.
In a Sunday statement, the WHO said the outbreak was probably associated with one seafood market in Wuhan, which had since been closed.
It also said it was “reassured of the quality of the ongoing investigations and the response measures implemented in Wuhan, and the commitment to share information regularly”.
The new virus was isolated, analysed and its genetic information released to the world 10 days after the confirmed outbreak. In 2003, it took more than three months to do the same with Sars.