Rats are a regular sight in New York, pilfering garbage cans or running across subway rails. However, these rats carry more than the regular run of the mill pathogens. Researchers from Columbia University have found that New York City rats carry thousands of diseases, some which were unknown to science.

The study, titled "Detection of Zoonotic Pathogens and Characterization of Novel Viruses Carried by Commensal Rattus norvegicus in New York City," was published on the mBio journal. The study involved 133 rats collected over the span of a year, according to ABC News.
The researchers discovered the rats carried diseases like salmonella and e.coli, expected from city-dwelling rodents; however, they also found rats that carried rare viruses like Seoul Hantavirus. The report's abstract details some of the 18 new diseases discovered.

"We also identified a wide range of known and novel viruses from groups that contain important human pathogens, including sapoviruses, cardioviruses, kobuviruses, parechoviruses, rotaviruses, and hepaciviruses," the abstract explains.

According to Dr. Ian Lipkin, an infectious disease expert at the Columbia University Mailman School of Public Health, the idea for the study stemmed from the September 11 terrorist attacks.

"We decided to get a baseline to figure out what was in New York City streets and elsewhere so if something new appeared then we'd know it," Lipkin told ABC News.

Lipkin explains the rats can transmit diseases in many ways and said the study could explain unknown causes for diseases like hepatitis.

"Rats are sentinels for human disease," he said. "They're all over the city; uptown, downtown, underground. Everywhere they go, they collect microbes and amplify them. And because these animals live close to people, there is ample opportunity for exchange."

Peter Daszak of the EcoHealth Alliance, an international organization that focuses on the conservation of biodiversity, warned about the potential danger posed by rats, according to WABC.

"If we don't do anything about it and continue to let rats get in and out of our restaurants, we're going to see a real public health issue arise, this is a wakeup call," Daszak said.

According to pest control company Orkin, New York is the fourth most rat-infested city in the country.