New Viruses And Superbugs Found In House Mice Droppings In New York

House mice are abundant in New York City. From ground level low rent studios to upper-class penthouses, they infiltrate every corner of the city. And now, a new study has confirmed that these mice carry new viruses and potentially deadly superbugs.

According to CNN, a yearlong assessment of the city’s residential mouse population found that what many of these rodents do carry are previously unseen viruses as well as bacteria capable of causing life-threatening human illness. Some of the bacteria carried by these mice were even antibiotic-resistant. New research on the mice that inhabit most New York City domiciles was published Tuesday in mBio, the journal of the American Society for Microbiology.

“Mouse droppings may contain harmful bacteria that are difficult to treat with common antibiotics,” said Dr. W. Ian Lipkin, senior author of the two papers resulting from the study and a professor of epidemiology at Columbia University’s Mailman School of Public Health. “Contaminated areas should be thoroughly cleaned, and contaminated food should be discarded.”

Lipkin and his colleagues collected 416 mice from residential buildings at seven sites in four of New York City’s five boroughs (Staten Island was excluded) over the course of one year in order to conduct this study. Primarily, the scientists caught the mice in or around garbage disposal areas in sub-basements, though five mice were trapped in food preparation/storage areas of a commercial building, and a single mouse was imprisoned in a private apartment.

For one of the two papers, Lipkin and his team searched for and analyzed bacteria in the droppings of the captured mice. Running genetic tests, the researchers defined 235 separate genera and 149 distinct species of bacteria, including the most common causes of human’s gastrointestinal upset: C. difficile, E. coli, Shigella and Salmonella.Salmonella alone causes 1.2 million reported cases, including 450 deaths, in the US each year and is the leading cause of food poisoning illnesses in humans.

The second paper concerned the viral load of the mouse droppings. For this study, the researchers discovered 36 separate viruses, including six new ones. None of the viruses identified by the researchers is known to infect humans, however, the genetic sequences matched those known to infect dogs, chickens, and pigs. This suggests that some of the viruses might have crossed over from other species.

Though New Yorkers tend to be most squeamish about rats, “mice are more worrisome because they live indoors and are more likely to contaminate our environment,” said Lipkin, who is director of the Center for Infection and Immunity at Mailman. “To our knowledge, this is the first such survey in NYC,” he said, adding that the laboratory work was “substantial.”