House fly, Musca domestica, (Diptera: Muscidae) dispersal from and Escherichia coli O157:H7 prevalence on dairy farms in North Central Florida

Cattle serve as the primary reservoir for Escherichia coli O157:H7, a pathogen responsible for several recent disease outbreaks, food recalls, and some deaths. The house fly, Musca domestica L. (Diptera: Muscidae), is implicated in transmission of this pathogen from dairy farms into nearby human populations. This study documents seasonal prevalence of both M. domestica and E. coli O157:H7 at two dairy farms in north central Florida. Escherichia coli O157:H7 was isolated from house flies collected from farms and from restaurant garbage dumpsters located in a nearby town. Additionally, E. coli O157:H7 was isolated from farm environmental samples, including manure and spilled grains. This study also demonstrates the consistent dispersal of house flies towards a nearby town by use of a fluorescent dust marker. Marked and released flies were recaptured in multiple locations, including outside a town restaurant, strengthening the strong potential for successful transmission of E. coli O157:H7 from cattle hosts to humans by house flies.