Temporal trends in Giardia occurrence in the Grand River and surrounding tributaries, Waterloo, Ontario (2005-2013), a retrospective analysis of surveillance data

Microbial water quality at contrasting recreational areas in a mixed-use watershed in eastern Canada

Recreational water use is an important source of human enteric illness. Enhanced (episodic) surveillance of natural recreational waters as a supplement to beach monitoring can enrich our understanding of human health risks. From 2011 to 2013, water sampling was undertaken at recreational sites on a watershed in eastern Canada. This study compared the prevalence and associations of human enteric pathogens and fecal indicator organisms. Beach water samples had lower pathogen presence than those along the main river, due to different pollution sources and the hydrological disposition. Pathogen profiles identified from the beach sites suggested a more narrow range of sources, including birds, indicating that wild bird management could help reduce public health risks at these sites. The presence and concentration of indicator organisms did not differ significantly between beaches and the river. However, higher concentrations of generic Escherichia coli were observed when Salmonella and Cryptosporidium were present at beach sites, when Salmonella was present at the river recreational site, and when verotoxigenic E. coli were present among all sites sampled. In this watershed, generic E. coli concentrations were good indicators of potential contamination, pathogen load, and elevated human health risk, supporting their use for routine monitoring where enhanced pathogen testing is not possible.

Urban public squares as potential hotspots of dog-human contact: A spatial analysis of zoonotic parasites detection in Gran Santiago, Chile

Zoonotic parasites are a major public health problem globally, representing a hazard to human health. The infections occur through contact with different parasite forms. Public squares are a common meeting place for people and dogs, becoming a risk area for transmission to other dogs and humans. A spatial analysis of zoonotic parasite distribution in urban public squares in Gran Santiago, Chile was performed to elucidate its importance, exploring spatial aggregation on positivity rates at commune level. A total of 170 stool samples were analysed; 54 (31.7%) were positive for gastrointestinal-zoonotic parasites. Positivity was detected in 27 (79.4%) squares. Diversity of parasite species was variable across sites. Toxocara canis was the most frequently detected (27 samples, 21/34 squares), followed by Toxascaris leonina (13 samples, 10/34 squares), cestode eggs (10 samples, 9/34 squares), Giardia sp. (6 samples, 5/34 squares), Ancylostomatidae-like eggs (4 samples, 4/34 squares), Cryptosporidium spp. (2 samples, 2/34 squares) and Entamoeba spp. (1 sample, 1/34 square). Spatial autocorrelation (SA) was observed at commune level. The local indicators of the spatial association test showed statistical significance for cestode eggs (p < 0.001) with a negative SA (Moran's I Index = -0.2929, CI-95% = -0.3869--0.1989) and Ancylostomatidae (p = 0.046) with a positive SA (Moran's I Index = 0.1404, CI-95% = 0.0499-0.2309). Toxocara canis is the most prevalent geo-helminth in public places of Santiago, Chile. Spatial autocorrelation was detected for cestode eggs and Ancylostomatidae. Diagnosis and detection of parasites is key for the establishment of control/eradication of environmental dissemination following One Health guidelines.