A new study suggests that animals carrying coronaviruses such as COVID-19 can infect thousands of people annually in China and Southeast Asia.
Researchers from the EcoHealth Alliance and the Duke-NUS Medical School in Singapore have raised an alarm over the potential for a new pandemic from spillover incidents.
The study, peer reviewed and released Thursday ahead of publication, estimates that 400,000 such infections occur each year. However, most of them go undetected because they have either mild or no symptoms and are not easily transmitted between people.
It said each spillover event – when a virus overcomes naturally occurring barriers to “spread” from one species to another – could lead to a Covid-like outbreak.
The origin of the novel coronavirus, which causes Covid, remains a mystery and has become a subject of controversy among world leaders and experts alike, years after the disease emerged and became a pandemic.
At the center of the controversy are two theories that suggest that the deadly virus is either naturally “spread” from bats to humans via an intermediary host animal or that the virus is transmitted as a result of a laboratory leak.
Research by the New York-based EcoHealth Alliance and the Singapore Medical College builds on earlier theory that bats are the main host-animals for the virus and that those living around mammals are most vulnerable.
The research was supported by the US National Institute of Allergy and Infectious Diseases.
Edward Holmes, a biologist at the University of Sydney who was not involved in the research, told Bloomberg, “This is perhaps the first attempt to estimate how often people are infected with Sars-related coronaviruses from bats.”
He said it was not unusual for humans to come into contact with bat coronaviruses. “Given the right set of circumstances, one of these could eventually lead to an outbreak of disease,” he said.
The Asian subcontinent is home to about two dozen bat species that can be infected with coronaviruses. According to the study, parts of southern China and Myanmar, Laos, Vietnam and Indonesia were found to be most vulnerable to spillovers.
Mr Holmes said: “It’s just bats. The risk of exposure is even greater when you factor in all potentially intermediate animal species.”
The study found that in Asia alone, about 478 million people live in areas where bats carrying the corona virus live.
Peter Daszak and his colleagues at the New York-based EcoHealth Alliance estimate that there are about 50,000 bat-to-human spillover events annually in Southeast Asia and that the conservative figure could actually run into the millions.
Dr Daszak has faced criticism from several quarters for collaborating on research funded by the National Institutes of Health at the Wuhan Institute of Virology, which has been at the heart of the lab-leak theory.
The theory, previously dismissed as a far-right conspiracy theory, has since been accepted by many in the scientific community.
Credit: www.independent.co.uk /