NWHC: Screening for potential human pathogens

Resident populations of Canada geese (Branta canadensis) and ducks have increased to high numbers, particularly in urban and suburban areas, throughout the United States and in other countries. The earliest complaints related to expanding goose populations, from the 1940's to the 1970's, were mainly damage to crops in populations of Canada geese using urban and suburban areas increased as did the number of complaints related to the nuisance created by excess fecal material. Goose feces have been implicated in eutrophication of small ponds and lakes as well as contamination of school yards, parks and boating and swimming areas (Conover & Chasko, 1985; Cooper & Keefe, 1997). An overriding concern of the public in most areas with high densities of Canada geese is the possibility of disease transmission to humans from direct contact with fecal material or contaminated water Agencies receive numerous requests for information on diseases of Canada geese and ducks that are transmissible to humans. These same agencies receive annual requests for reduction in numbers or complete removal of waterfowl based in part on concerns for public health. Several studies have been conducted to detect the presence of bacterial pathogens in fecal material of migratory waterfowl. Campylobacter jejuni, which causes acute diarrhea in humans, was isolated from caeca of 154 (35%) of 445 ducks killed by hunters in Colorado (Luechtefeld, et al., 1980). During a banding study in Washington, Pacha et al. (1988) collected cloacal swabs from ducks and recovered Campylobacter spp. from 82 (73%) of 113 samples. In addition, they collected recently deposited fecal material from fields with flocks of Canada geese and sandhill cranes (Grus canadensis); Campylobacter spp. were isolated from five of 94 (5%) fecal samples from Canada geese and 74 of 91 (81%) fecal samples from sandhill cranes (Pacha, et al., 1988). An earlier study by Hill and Grimes (1984), in the Wisconsin-Minnesota region of the upper Mississippi River, found no Campylobacter spp. in 50 cecal samples from ducks killed by local hunters. Campylobacter spp. have been previously isolated from other birds (Waldhalm, et al. Listeria spp. have been isolated from avian species including geese (Gray, 1958; Seeliger, 1961), however the geese typically mentioned in studies were domestic species. Isolation of Listeria spp. from wild Canada geese has not been documented although other species of wild birds have been reported as having Listeria spp. To investigate the possibility of Listeria spp. transfer from seagulls and …