Coronaviruses very closely related to SARS-CoV-2, which can lead to COVID-19, was uncovered in a pair of bats sampled in Cambodia more than 10 years ago.
The discovery, outlined in the journal Nature Communications, further supports theories that the global pandemic was the result of a “spillover of a bat-borne virus.”
In December 2019, government officials in the Chinese city of Wuhan confirmed that health authorities were treating several cases of pneumonia of unknown cause. Just a few days later, researchers in China identified a new virus that had infected dozens of people across Asia. In the months since, there has been some mystery surrounding the origin of COVID-19.
Health experts, world leaders and internet users alike have floated varying hypotheses regarding the coronavirus source. Most infectious disease experts agree however, that it jumped undetected across the species barrier from bats to another animal, which then passed it to humans.
In the recent study, scientists relied on metagenomic sequencing to identify “the nearly identical viruses” in two Shamel’s horseshoe bats, initially sampled in 2010. According to the authors, the findings suggest “the current understanding of the geographic distribution of the SARS-CoV and SARS-CoV-2 lineages possibly reflects a lack of sampling in Southeast Asia.”
In addition to bats, authors warned that certain species of cat, civet, and weasels found in the region are susceptible to SARS-CoV-2 infection, and could ultimately serve as intermediary hosts for transmission to humans. What’s more, groups of pangolins seized during anti-smuggling operations in 2020 showed signs of viruses of the SARS-CoV-2 sublineage.
While it’s unclear where exactly the animals became infected, authors noted the pangolin species involved also “corresponds to Southeast Asia and not China.”
“Southeast Asia hosts a high diversity of wildlife and an extensive wildlife trade that puts humans in direct contact with wild hosts of SARS-like coronaviruses,” said Lucy Keatts of the Wildlife Conservation Society’s (WCS) Health Program and a co-author of the study.
“The region is undergoing dramatic land-use changes such as infrastructure development, urban development, and agricultural expansion that can increase contacts between bats, other wildlife, domestic animals and humans. Continued and expanded surveillance of bats and other key wild animals in Southeast Asia is a crucial component of future pandemic preparedness and prevention.”
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