Pathogen Loading From Canada Geese Faeces in Freshwater: Potential Risks to Human Health Through Recreational Water Exposure

Abstract

Canada geese (Branta canadensis) faeces have been shown to contain pathogenic protozoa and bacteria in numerous studies over the past 15 years. Further, increases in both the Canada geese populations and their ideal habitat requirements in the United States (US) translate to a greater presence of these human pathogens in public areas, such as recreational freshwater beaches. Combining these factors, the potential health risk posed by Canada geese faeces at freshwater beaches presents an emerging public health issue that warrants further study. Here, literature concerning human pathogens in Canada geese faeces is reviewed and the potential impacts these pathogens may have on human health are discussed. Pathogens of potential concern include Campylobacter jejuni, Salmonella Typhimurium, Listeria monocytogenes, Helicobacter canadensis, Arcobacter spp., Enterohemorragic Escherichia coli pathogenic strains, Chlamydia psitacci, Cryptosporidium parvum and Giardia lamblia. Scenarios presenting potential exposure to pathogens eluted from faeces include bathers swimming in lakes, children playing with wet and dry sand impacted by geese droppings and other common recreational activities associated with public beaches. Recent recreational water-associated disease outbreaks in the US support the plausibility for some of these pathogens, including Cryptosporidium spp. and C. jejuni, to cause human illness in this setting. In view of these findings and the uncertainties associated with the real health risk posed by Canada geese faecal pathogens to users of freshwater lakes, it is recommended that beach managers use microbial source tracking and conduct a quantitative microbial risk assessment to analyse the local impact of Canada geese on microbial water quality during their decision-making process in beach and watershed management.

Potential disease transmission from wild geese and swans to livestock, poultry and humans: a review of the scientific literature from a One Health perspective

“…[96] Refsum alone and together with co-workers [85,90] proposed that the importance of waterfowl in spreading Salmonella bacteria is limited, except for birds resident in areas highly contaminated by human waste or domestic animal manure. However, Gorham and Lee [5] rather emphasized the uncertainty of assessments of potential risks, especially in relation to Canada geese. There are no studies directly linking outbreaks of salmonellosis in humans, livestock or domestic poultry to the presence of swans and geese or their faeces.…”

“…[165,166] Although sometimes stated that such transmission is not well understood or documented, a general advice is nevertheless to minimize direct contact between humans and goose faeces. [166] Furthermore, Abulreesh et al [167] argued that skin contact and accidental ingestion of contaminated water from amenity village ponds harbouring waterfowl should be avoided, and Gorham and Lee [5] concluded that as Canada geese can indeed be an important source of faecal contamination of recreational waters, population control of this species may be considered for public health reasons.…”

“…Although there are well-described local cases for most of these conflicts, their prevalence and consequences over larger spatial and temporal scales have only recently been reviewed comprehensively and critically. [3][4][5] A recurring issue in this context is geese and other waterfowl as sources of infections (e.g. [6]).…”

“…Another concern is that large goose flocks for prolonged periods roost on lakes and wetlands where livestock drink and humans extract drinking water and swim. [5] On top of this, most goose populations are highly mobile, on a daily as well as a seasonal basis, making them potential disease vectors at short and medium spatial scales.…”

Prevalence ofSalmonellaamong waterfowl along the Texas Gulf coast

“…In urban and suburban areas, large flocks of waterfowl can generate substantial accumulations of faeces in recreational parks and private lawns (Conover, ; Feare, Sanders, Blasco, & Bishop, ). Waterfowl and other birds have also been found to be a significant source of faecal material in recreational waters (Edge & Hill, ; Gorham & Lee, ; Meyer, Appletoft, Schwemm, Uzoigwe, & Brown, ). In rural areas, waterfowl frequently occupy agricultural fields and surface waters for resting and feeding (Fox, Elmberg, Tombre, & Hessel, ), with possible implications for food safety.…”