The results suggest that the coronavirus could be transmitted on a large scale from humans to rodents in the city. They come as the FBI director’s comments reignite a fierce debate in the United States over the alleged origins of the disease – with suspicion once again falling on a Chinese lab.
By Tom Acres, Technology Journalist
Thursday, March 9, 2023 4:00 p.m., UK
Millions of rats living in New York are susceptible to COVID-19, researchers have found.
Like humans, rodents have been shown to be vulnerable to multiple variants of the virus, from the original to Omicronincluding high levels of infection in their upper and lower respiratory tract.
A report by the World Health Organization (WHO) in 2021 concluded that the coronavirus is “likely” to have been transmitted from bats to humans via an unknown animal.
Since then, cases of human-to-animal transmission have been reported – including pets.
Researchers at the University of Missouri investigated whether new YorkThe rats could be infected, given the large number that live in the city.
There are about eight million wild rats in the Big Appleand they are also widely distributed in other urban areas across the WE.
The peer-reviewed study, published in the American Society for Microbiology’s mBio journal, said determining whether wild animals could be infected on a large scale was key to tracking the evolution of the virus.
Rats captured near sewers
“To our knowledge, this is one of the first studies to show SARS-CoV-2 (the virus that causes COVID-19) variants can cause infections in wild rat populations in a large urban area of the United States,” said lead author Dr. Henry Wan.
With permission from local officials, researchers conducted two operations to trap the rats in and around locations surrounding the city’s sewer systems – primarily in Brooklyn.
Sewer monitoring has been used during the pandemic to detect rates of the disease.
Biologists collected and processed samples from 79 rats captured between September and November 2021 and found that 13 of them (16.5%) had COVID-19.
At the scale of the total estimated population, that would mean more than 1.3 million infected rats in New York.
Work can help track whether the virus is ‘evolving’
Dr Wan, who specializes in emerging infectious diseases, said the findings reinforce the joint role humans and animals can play during a pandemic.
“It is important that we continue to increase our understanding so that we can protect both human and animal health,” added the professor.
“Our results highlight the need for further surveillance of SARS-CoV-2 in rat populations to determine whether the virus is circulating in animals and evolving into new strains that could pose a risk to humans. “
Previous research has warned that as transmission decreases in society, COVID among animals could become an “increasingly important potential source (…) of reintroduction of the virus in humans”.
However, the presumed zoonotic (animal to human) origins of the virus have come into question in recent weeks after the FBI director revealed the US intelligence agency thinks it is “most likely” leaked from a Chinese lab.
The theory has been peddled since the initial outbreak in Wuhan, China more than three years ago, but the official WHO position is that it remains “extremely unlikely”.