Are millions of NYC rats carrying COVID?

Are millions of NYC rats carrying COVID?

A study finds that the millions of Norway rats that live alongside New Yorkers are among the animals that can catch the virus that causes COVID-19. By testing the rats with samples of virus variants, researchers found that the variants Alpha, Beta, Delta, and Omicron can infect rats highlighting the potential risk of secondary zoonotic transmission. 

NYC's rats found infected with virus that causes COVID

With our safe and effective rodent control solution RatX®, we have joined the New York Pest Management Association (NYPMA) and the New Jersey Pest Management Association (NJPMA) to help control rat populations and address outbreaks. 

Despite best efforts, the New York City rat population is over 2 million, with reports of rat sightings doubling since 2022. A study published by the American Academy of Microbiology in their journal mBio finds that the millions of Norway rats that live alongside New Yorkers are among the animals that can catch the virus that causes Covid-19. Once again, this raises the question of possible rat-human transmission, although current reports of the virus spreading from these animals to humans remain rare. 

Study findings

In the fall of 2021, when Delta was the dominant strain, the teams set up two trappings and captured 79 rats from three sites and around city parks in Brooklyn. Researchers wanted to understand if the virus in humans had become transmitted to rats and which variants the rats were susceptible to. More advanced lab studies aimed to determine if the wild rodents were vulnerable to the virus and if they could catch several variants. 

“To the best of our knowledge, this is one of the first studies to show SARS-CoV-2 variants can cause infections in the wild rat populations in a major U.S. urban area,” Dr Henry Wan of the University of Missouri said.

This study concludes that rats likely came into contact with SARS-CoV-2 through their close cohabitation with humans. Analysis suggests that the viruses found in the tested Norway rats were associated with the B-lineage virus – the predominant virus in NYC during the beginning stages of the pandemic. 

“Thirteen, or 16.5%, of the 79 rats were found to have IgG or IgM antibodies against the virus, suggesting a previous infection with SARS-CoV-2,” the study reports. Research also projects an estimated 1 million+ of the citywide rat population may show the same immune response to SARS-CoV-2.

How did rats contract SARS-CoV-2?

There has been the suggestion that rats became exposed to the virus through sewage water systems since the discovery of SARS-CoV2 in these systems. However, research concludes that there is no evidence that these viruses in sewage waters are infections, leading researchers to fortify their claim that sewage rats may become exposed through “airborne transmission, e.g., overlapping living spaces with humans or indirect transmission from unknown formities, e.g., contaminated human food waste.” 

More study is required to understand the significance of this new research and findings as well as the full implications and what this means for humans, “...particularly for several emerging variants with high infectivity among rats, including those that circulated in NYC during the past 2 years of the COVID-19 pandemic,” the report states.

By testing the rats with samples of virus variants, researchers found that the variants Alpha, Beta, Delta, and Omicron can infect rats highlighting the potential risk of secondary zoonotic transmission. 

“The tested variants also replicated to high levels in both the upper and lower respiratory tracts of rats, although they did not cause any bodyweight loss or other clinical signs,” research states, and “of the three variants, Delta replicated the most efficiently.”

Although there is little risk of animals spreading COVID-19 to humans, it is crucial to continue monitoring rat populations to watch for the evolution of new strains of Alpha, Delta, and Omicron because of the potential of new variants emerging in rats that may contain properties that are harmful to humans. An example is the proposed study that mice could be associated with the emergence of Omicron variants.

Help from RatX®

This study is a much-needed reminder that the virus continues to circulate. There is a need to keep these findings in mind when planning for the future to ensure continued protection against potential outbreaks. With NYC rat sightings doubling in 2022, there are many reasons to stay on top of rodent control; adding the potential of new variants spreadable from rats to humans is a basis to take precautionary measures.

EcoClear Products has long been an industry leader in effective, poison-free pest control. Present at pest control and pest management conferences throughout the United States, we aim to educate industry leaders and various sectors through our extensive knowledge and research. 

RatX® is a fast, safe, and effective way to eliminate and control rodent populations. Scientifically formulated to produce quick results, we teamed up with NYPMA and NJPMA to do everything we can to provide non-poisonous pest solutions with no risk to people, pets, or non-target wildlife. 

Controlling the increasing rodent population and outbreaks and continuing research on rats contracting COVID is essential. With new discoveries and findings, not only could rats become a source of reinfection for humans, but they could also become a source of new variants in the future.