Prevalence of Cryptosporidium, Giardia, Salmonella, and Cephalosporin-Resistant E. coli Strains in Canada goose Feces Urban and Peri-Urban Sites in Central Ohio

Large populations of resident geese can pose a pathogen exposure hazard and disease risk to humans and animals in urban areas. Evidence suggests that waterfowl play a role in pathogen dissemination and disease transmission to humans, however, more definitive data are often needed. This exploratory study sought to identify potential exposure hazards, the first step in risk assessment. This research also discusses dose-response for protozoan organisms and initiated the exposure assessment process by measuring environmental variables that may be associated with exposure. A total of 199 Canada goose fecal samples were collected from 5 peri-urban and 7 urban sites throughout the Greater Columbus, Ohio area. Samples were collected during two time periods: during 4-11 June, 2013 when geese had just begun their molt, and 16-30 August, 2013 after geese regained flight. Juveniles were distinguished from adults only during the first sample period. Antigen capture enzyme-linked immunosorbent assay (ELISA) was used to detect presence of Giardia and Cryptosporidium. Selective media were used to culture Salmonella and cephalosporin-resistant E. coli strains. Cryptosporidium was the most prevalent pathogen with 44.7% of samples testing positive. Feces collected from urban sites during the first period were 1.86 times more likely to be positive for Cryptosporidium than peri-urban sites (P = 0.10). Forward model selection methods determined that prevalence was positively associated with human population density surrounding collection sites, proportion of each site defined as pasture by the National Land Cover Database (NLCD), and distance of each site from nearest wastewater treatment plant (WWTP). Feces collected from urban sites during the second period were no more likely to be positive for Cryptosporidium than peri-urban sites (P = 1.00, Odds Ratio= 1.00). Forward stepwise model selection determined that prevalence was positively associated with human population density within study sites, distance of each site from nearest livestock farm, and distance of each site from nearest wastewater treatment plant.Giardia was present in only 3.5% of samples. None were positive for Giardia in the first period. Feces collected from urban sites during the second period were 1.9 times more likely to be positive for Giardia than peri-urban sites (P = 0.74). Prevalence of cephalosporin-resistant E. coli strains was 10.8%. Only one positive was detected during the first period. Feces collected from urban sites during the second period were 6.7 times more likely to be positive for cephalosporin-resistant E.coli than peri-urban sites (P = 0.10). No Salmonella was detected in the fecal samples. All pathogens tested, with the exception of Salmonella, showed a similar trend where a greater percentage of positives were detected at urban sites than peri-urban sites. The exposure potential of goose feces to the human population appears to be high for Cryptosporidium but low for Giardia and Salmonella. The discovery of cephalosporin-resistant strains of…