BEIJING • The Chinese city of Wuhan in Hubei province may not have been the place where the Covid-19 virus crossed from animals into humans, despite the first clusters of infections having been reported in the city, said Dr Michael Ryan, executive director of the World Health Organisation's (WHO) Health Emergencies Programme.
The city had a surveillance system designed specifically for picking up atypical pneumonia cases, he told a news briefing on Monday.
"It was there for a very specific purpose. And the fact that the fire alarm was triggered doesn't necessarily mean that is where the disease crossed from animals into humans," he said.
Commenting on the future joint investigation, Dr Ryan said Chinese scientists have done a lot of great work and provided valuable preliminary data.
A more extensive epidemiological study to look at the first cases and clusters in Wuhan will begin, with the participation of scientists from around the globe.
Two WHO experts were in China from July 11 to Aug 2 to conduct groundwork for an investigation into the animal origins of the coronavirus, according to information released by China's National Health Commission on Monday.
The experts held many talks with their Chinese counterparts on scientific research, including the route of transmission and animal origin of the virus, and exchanged ideas on future scientific study plans.
WHO director-general Tedros Adhanom Ghebreyesus said the WHO and Chinese experts have drafted the terms for the studies and the programme for an international team led by the WHO.
"The international team will include leading scientists and researchers from China and around the world," he said.
The origin of the coronavirus has puzzled scientists since its discovery. A study published late last month in the journal Nature Microbiology said scientists now have further proof that the virus evolved in the wild and may have been circulating in bats for more than 40 years.
The study, conducted by scientists from China and Europe, said the virus may have been poised to jump to humans for some time.
This discovery discredits conspiracy theories that the coronavirus was bio-engineered or had escaped from a lab, it added.
The researchers compared the genetic make-up of the coronavirus with that of a close relative in bats - a virus called RaTG13.
The latter was discovered by noted Chinese virologist Shi Zhengli in Yunnan province in 2013, according to the journal Science.
As a result, RaTG13 has been the centrepiece of many conspiracy theories claiming Dr Shi's team had genetically manipulated it to create the coronavirus. Dr Shi rebutted all the accusations in an interview with Science last month.
The latest study found that the two viruses shared a common ancestor, but their evolutionary path diverged some 40 to 70 years ago. This long divergence suggests that there may be other undiscovered strains of bat coronaviruses that may cause disease in humans.
Dr David Robertson, a professor of viral genetics at the University of Glasgow in Britain and one of the key researchers behind the study, said the coronavirus is a generalist virus that can infect multiple species of animals.
"Current evidence suggests that the novel coronavirus acquired its significant traits from evolving in bats, not in some intermediate hosts," he said last month. This may help explain why the intermediate host has eluded scientists to this day, as it may not have played a big role in the virus' evolution, he said.
CHINA DAILY/ASIA NEWS NETWORK