A study published in mBio (shout out for OpenAccess!) found that rats in New York City are very, very, very ‘dirty.’ The authors (Shout out to Columbia!) analyzed the pathogens carried by 133 rats using high-throughput genetic sequencing, and discovered that NYC rats carry many bacteria and viruses that can cause human disease! Press release here.
We found that these rats are infected with bacterial pathogens known to cause acute or mild gastroenteritis in people, including atypical enteropathogenic Escherichia coli, Clostridium difficile, and Salmonella enterica, as well as infectious agents that have been associated with undifferentiated febrile illnesses, including Bartonella spp., Streptobacillus moniliformis, Leptospira interrogans, and Seoul hantavirus. 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.
That’s not good. Now, I’ll only be thinking about all of these pathogens when I’m waiting on the subway platform and look down to see the most common NYC wildlife under the tracks. Guess we should all be paying a little more attention to the diseases that these rats are carrying around all over our city.
Our findings indicate that urban rats are reservoirs for a vast diversity of microbes that may affect human health and indicate a need for increased surveillance and awareness of the disease risks associated with urban rodent infestation.
For all of the curious minds like me, you have to ask yourself… where did they get these rats? and how did they catch them? First off, the rats were humanely euthanized after being trapped. Below are the methods from the paper describing the rat collection.
The preliminary nature of this study and the significant complexities involved in trapping rats indoors in NYC necessitated an approach of convenience sampling. An effort was made to target neighborhoods likely to be impacted by the presence of rats, specifically those with high rodent and human density or a high probability of rodent-human interaction. Five sites were selected in midtown and lower Manhattan, comprised of three high-density housing complexes, one very large indoor mixed-use public space (transportation, food service, retail, and commercial), and one small urban park in a densely populated area. The residential sites are on blocks of average density for Manhattan and below-average median income (64). The mixed-use public space is in a neighborhood notable for an exceptionally high daytime population size and density, and the park was chosen based both on its location (adjacent to the residential sites) and high block density.
For extra fun, check out this video about the study from Slate!