A coronavirus isolated from pangolins is a 99 per cent genetic match to the one that has killed more than 600 people since an outbreak began in central China last month, according to a study by a team of Chinese civilian and military scientists.
Scientists have traced the origin of the 2019-nCoV coronavirus to a fruit bat found in Yunnan province a few years ago, but about 4 per cent of its genes were new. This suggested an intermediate host, and some studies had proposed various candidates such as snakes.
The team led by Professor Shen Yongyi at the South China Agricultural University in Guangzhou, Guangdong province, analysed more than 1,000 samples and found that more than 70 per cent of the pangolins they examined carried viruses that were from the same family as the infection found in the city of Wuhan, the scientists said on Friday.
At the microscopic level, the civilian researchers and their colleagues from the Academy of Military Medical Sciences in Beijing found that some pangolin viral strains appeared identical to the new coronavirus in humans – and further analysis showed they had 99 per cent of their genes in common.
“Pangolins are potential intermediate hosts, but there may be multiple intermediate hosts,” Shen said. “For example, with Sars [severe acute respiratory syndrome] in addition to civets, other small predators may also spread the virus.
The team’s results have not been through the peer review process and a formal research paper was not available.
“In view of the seriousness of the current epidemic, we hope to make the research results public as soon as possible, aiming to help scientific prevention and control of the epidemic and provide references for more scientists to conduct further work,” Liu Yahong, president of the university, was quoted by news website Thepaper.cn as saying.
Typically scientists put their findings in a paper for publication in an academic journal, then a peer review would be ordered before the results were made public.
This takes time, and scientists have been under pressure from the public and fellow researchers to work quickly during the coronavirus outbreak.
Zheng Aihua, a virologist with the Institute of Zoology at the Chinese Academy of Sciences in Beijing, said a paper and data were still necessary for the researchers worldwide to evaluate and expand upon the work.
“Many theories abound,” he said. “We need to be careful and not hurry to make a conclusion.”
Some questions about links to 2019-nCoV remained. For instance, bats and pangolins lived in different environments. Although both were nocturnal mammals, it was unclear how the virus jumped from bat to pangolin.
The pangolin is a scaly anteater, and one of the most sought-after species in the illegal animal trade. Unlike the bat, the pangolin is a popular ingredient in restaurants and herbal medicines.
More than 1 million have been killed worldwide over the past decade to meet black market demand for their meat or scales, and most of those originated in China, according to estimates.