China’s wildlife trade should be thoroughly investigated as part of efforts to uncover the origin of the coronavirus pandemic, researchers have said even as the World Health Organization (WHO) has rushed its scientists to the dragon country, ahead of plans for a larger international research team to probe the pandemic’s origin.
“The mission objective is to advance the understanding of animal hosts for Covid-19 and ascertain how the disease jumped between animals and humans,” said Tedros Adhanom Ghebreyesus, the WHO’s director-general, recently
The team will work closely with officials and the scientific community in China to decide what kind of investigations are needed and where, said Michael Ryan, director of the WHO’s emergencies programme. He said a good place to start is in Wuhan, where the first clusters of atypical pneumonia emerged.
Researchers said the focus should be on activities linked to China’s wildlife trade — both legal and illegal — including hunting areas, storage facilities, farms and markets. “All parts of the wildlife supply chain need to be investigated,” said Alice Latinne, an evolutionary biologist at the Wildlife Conservation Society Vietnam in Hanoi. “We need to test any wild or farmed wild animal species that could potentially be in close and frequent contact with humans in China,” she said.
Most researchers agreed that the SARS-CoV-2 virus probably originated in horseshoe bats, but the route it took to get to humans remains a mystery. The virus could have jumped directly from bats to people and evolved over time into the current pandemic strain, or it could have passed through intermediate animals.
Researchers pointed out that the wildlife trade — in which many animals come into close proximity with each other and people — offers the perfect conditions for a virus in one species to spill over into another.
The investigators should scrutinize the circumstances in which the pangolins in China were seized, the animal species they were housed with, and whether people involved in the wildlife trade have coronavirus antibodies, said Arinjay Banerjee, a coronavirus researcher at McMaster University in Hamilton, Canada. Following that trail could help scientists find a closer relative to SARS-CoV-2, he said.
The WHO investigations should also look at other mammals commonly hunted and traded in southern China, especially small carnivores and rodents, said Latinne. Another priority should be bats in the southern province of Yunnan, she said — a hotspot for bat coronaviruses where the closest known relative to SARS-CoV-2, called RaTG13, has been identified.
Researchers should also keep an open mind, and look beyond the wildlife trade and known coronavirus reservoirs, added Sophie Gryseels, an evolutionary biologist at the Catholic University of Leuven, Belgium.