Source: James M. Clinton, “Rats in Urban America” Public Health Rep. 1969 January; 84(1) http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2031432/?tool=pmcentrez&rendertype=abstract
In the study, researchers discuss the evolution of rat populations in urban cities of American and how their rising presence has led to the problem of rat bites and their sequelae. Prior to the 1960’s, metropolitan areas were not highly developed and had a relatively lower population compared to the rural areas. As a result, rat-bite incidences were not as prevalent and almost unheard of in urban cities. As cities developed, the problem of rat-bites rapidly increased and led to the development of public laws, which require documentation of rodent bites. In NYC, the department of health keeps year-to-year records of rat-bites and diseases transmitted through them.
According to the study, public health problems are generally caused by three rat species that are Norway rat, the roof rat and the house mouse. The Norway rat exhibits less fear around humans and will make contact with motionless persons, whereas the roof rat better adapts to the environment than the Norway rat, but generally stays hidden in lofts, attics and trees. Nevertheless, the house mouse usually contributes the greatest to property damage and food contamination. Americans incur over $900 million/year in property and grain crop damages. In terms of diseases, rats contribute to greater than 6000 cases/year of diseases and serve as vectors and reservoirs of salmonellosis, leptospirosis, rat-bite fever and murine typhus. Out of the three primary urban rat species, Norway rats inflict the greatest number of diseases caused by bites. Furthermore, the total incidence of rat bites is currently at 10/100,000 in urban areas. These rodents quickly access homes through plumbing fixtures, doors and windows and cause a major public health concern.
The rodent population is a major concern to NYC, because its environment does provide suitable breeding grounds for all three major urban rats. They are vectors of several diseases, and due to the high population density the spread of these diseases can significantly multiply just after few outbreaks. It is highly essential to monitor rat-bite incidences and the potential threat of disease associated with it.
