In the search for the origin of an epidemic, groups of animals are often examined to identify the viruses they carry. In this study, a group of bats in Laos, one of China’s neighbors, was examined. “We know the types of bats that have those SARS-like viruses, so they are also found across the border of China, because their habitat does not stop at the border,” Koopmans says.
Viruses closely related to SARS-CoV-2, the cause of the COVID-19 epidemic, have now also been found in the cluster in Laos. “In addition, there is one that is almost as similar to SARS-CoV-2 as it was previously.”
cut and paste
The researchers also showed that mixed forms originate in the wild. As different viruses spread in groups of animals, a kind of cut and paste is created, which results in new viruses. “If an animal is infected with two viruses at the same time, some kind of mixture can arise,” Koopmans says. “The fact that SARS-CoV-2 is a kind of mixture is also used as an argument for a virus that has been tampered with in the laboratory, but this is absolutely not necessary. It also occurs in nature,” says the virologist.
Koopmans stresses that this study still does not provide a definitive answer to the question of where the coronavirus comes from. “It’s further evidence that this is a very plausible theory of origin,” she says.