Researchers discovered that millions of rats in New York City are susceptible to COVID-19.
The rodents, like people, have proven susceptible to numerous forms of the virus, ranging from the original to Omicron, with significant levels of infection in their upper and lower airways.
In 2021, the World Health Organization (WHO) found that the coronavirus was “likely” transmitted from bats to people via an unknown species.
Since then, there have been reports of human-to-animal transmission, including in pets.
Given the city’s large population of rats, researchers at the University of Missouri investigated whether they may be infected.
There are around eight million wild rats in New York City, and they are also widely distributed in other urban areas throughout the United States.
The peer-reviewed study, published in the journal mBio of the American Society for Microbiology, stated that it was critical to know whether wild animals could be infected at scale in order to follow how the virus would evolve.
Rats apprehended near sewage systems
“To our knowledge, this is one of the first studies to indicate that SARS-CoV-2 (the virus that causes COVID-19) variations can induce illnesses in wild rat populations in a major US urban region,” stated lead author Dr Henry Wan.
With the cooperation of local officials, researchers conducted two operations to catch rats in and around the city’s sewage systems, primarily in Brooklyn.
During the pandemic, sewer surveillance was utilised to detect disease rates.
Biologists gathered and analysed samples from 79 rats taken between September and November 2021 and discovered that COVID-19 was present in 13 of them (16.5%).
When multiplied by the total estimated population, that translates to more than 1.3 million afflicted rats in New York City.
Work can assist in determining whether a virus is ‘evolving.’
Dr. Wan, an expert on emerging infectious diseases, stated that the findings reinforced the collaborative role that humans and animals can play during a pandemic.
“It’s critical that we continue to expand our understanding so that we can preserve both human and animal health,” the professor stated.
“Our findings underline the importance of continuing to monitor SARS-CoV-2 in rat populations to identify if the virus is circulating and changing into new strains that could pose a risk to people.”
Prior research has warned that when human transmission declines, COVID in animals may become a “increasingly important […] possible source” of the virus reintroduction.
But, the virus’s purported zoonotic (animal-to-human) origins have been called into question in recent weeks, with the FBI’s director revealing that the US spy agency believes it “most likely” came from a Chinese lab leak.
The theory has been sold ever since the original epidemic in Wuhan, China, more than three years ago, but the WHO’s official opinion is that it remains “very implausible”.