An expert who was part of the World Health Organization (WHO) investigation into the origin of COVID-19 says that wildlife farms in southern China may have served as a key pathway in the early days of the disease outbreak.
Dr Peter Daszak, a disease ecologist from EcoHealth Alliance who served on the WHO delegation to track the origins of COVID-19, told NPR that their recent investigation found new evidence that wildlife farms were supplying vendors at the Huanan Seafood Wholesale Market in Wuhan with animals. He also believes that these wildlife farms may be a key piece of the puzzle when looking to explain how the virus spilled over into humans.
SARS-CoV-2, the virus responsible for COVID-19, is widely believed to have originated in bats. There’s a wealth of evidence to show that distinctly similar viruses to SARS-CoV-2 can be found in wild bats living in southern China. Furthermore, SARS – a related but distinct virus that caused an outbreak between 2002 to 2004 – has also been traced back to a population of cave-dwelling horseshoe bats in Yunnan, southern China.
However, the first human cases of COVID-19 were identified in inner-city Wuhan in central China’s Hubei province, a very long journey from the rural caves where these bats live. This has led to questions about how a virus most likely found in wild bats from southern China ended up in an urban environment in central China. According to Daszak, wildlife farms in southern China may be the missing link.
"China promoted the farming of wildlife as a way to alleviate rural populations out of poverty," Daszak told NPR. "They take exotic animals, like civets, porcupines, pangolins, raccoon dogs and bamboo rats, and they breed them in captivity," adds Daszak.
In this line of argument, it’s possible that wild bats transmitted the virus to some of the "wild" animals being farmed in rural stretches of southern China. Many of these farmed species – such as civet cats and pangolins – are known to carry coronaviruses. These infected animals were, in theory, then transported to locations in the inner cities, such as the Huanan Seafood Wholesale Market in Wuhan, where they were distributed.
Dr Daszak argues that China’s response to the initial outbreak seems to suggest they also suspected this might be a strong possibility. The Huanan Seafood Wholesale Market was shut down overnight on December 31, 2019, after it was linked to a number of early COVID-19 cases – known only then as a mysterious “pneumonia-like illness.” Numerous live animals kept at the market were later found to test positive for SARS-CoV-2 during an investigation by scientists in China.
As mentioned, the recent WHO mission found evidence that wildlife farms in southern China were supplying animals to the Huanan Seafood Wholesale Market. By February 2020, Chinese authorities also launched a declaration to shut down all of their wildlife farms. Daszak thinks they took this action because it was apparent the wildlife farms were a prime suspect in the origins of the zoonotic disease.
However, questions over the origin of COVID-19 are unlikely to be settled any time soon. The recent WHO mission to find the origins of COVID-19 recently released their initial findings after visiting key sites in China that have been suspected to play a role in the initial stage of the disease outbreak. While they did conclude it was "highly unlikely" the virus sprung from a lab, they failed to reach any hard conclusions.
The WHO plans to release its full report on the issue in the next few weeks.