Millions of rats living across New York City 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 a Omicronincluding high levels of infection in the upper and lower airways.
A report from the World Health Organization (WHO) in 2021 concluded that the corona virus it is “probable” that it was transmitted from bats to humans through an unknown animal.
Since then, cases of human-to-animal transmission have been reported: even in pets.
University of Missouri researchers looked at whether New YorkThe rats could be infected, given the huge numbers that call the city their home.
There are about eight million feral rats in the Big Appleand are also widely distributed in other urban areas throughout the WE.
The peer-reviewed study, published in the American Society for Microbiology’s journal mBio, said determining whether wild animals can be infected on a large scale is critical to keeping track of how the virus might evolve.
Rats caught near sewage systems
“As far as we know, this is one of the first studies to show SARS-CoV-2 (the virus that causes COVID-19) can cause infections in feral rat populations in a large urban area in the United States,” said lead author Dr. Henry Wan.
With the permission of local officials, the researchers carried out two operations to trap the rats in and around locations surrounding the city’s sewage systems, mostly in Brooklyn.
Sewer surveillance it has been used during the pandemic to track rates of the disease.
The biologists collected and processed samples from 79 rats caught between September and November 2021 and found that 13 of them (16.5%) had COVID-19.
Scaled up to the estimated total population, that would mean more than 1.3 million infected rats in New York City.
Work can help monitor whether the virus ‘evolves’
Dr Wan, who specializes in emerging infectious diseases, said the findings strengthened the joint role humans and animals can play during a pandemic.
‘It is important to continue to increase our understanding so that we can protect both human and animal health,’ added the professor.
“Our findings highlight the need for further monitoring 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 had warned that as transmission declines in society, COVID among animals can become an “ever more important […] potential source” of the reintroduced virus into humans.
However, the alleged zoonotic (animal to human) origins of the virus have been questioned in recent weeks after the FBI director revealed to the US intelligence agency he believes it “most likely” came from a leak from a Chinese lab.
The theory it has been peddled since the initial outbreak in Wuhan, China, more than three years ago, but the WHO’s official position is that it remains “extremely unlikely”.