Rodents can be asymptomatic carriers of viruses similar to SARS, which means the next devastating pandemic could come from rats, according to a study by Princeton University published in PLOS Computational Biology.
The researchers analyzed various mammalian species, focusing on those receptors that SARS viruses bind to. The results showed that some rodent species have been repeatedly exposed to SARS-like coronaviruses in the past and have developed some resistance to them.
“Our study suggests ancestral rodents may have had repeated infections with SARS-like coronaviruses. They have acquired some form of tolerance or resistance to SARS-like coronaviruses as a result of these infections,” said Professor Mona Singh.
The study showed that rats underwent a rapid evolution of the ACE2 receptor, which SARS viruses use to enter a cell. This is indicated, in particular, by the wide variety of amino acid sequences encoding the receptor.
“This raises the tantalising possibility some modern rodent species may be asymptomatic carriers of SARS-like coronaviruses - including those that may not have been discovered yet,” Singh said.
As the SARS-CoV-2 virus could be transmitted from animal to person, identifying animals that carry viruses while being protected against them could become vital to prevent future outbreaks, the scientists noted.