Groundwater contamination by Cryptosporidium oocysts from animal faeces in the city of Les Cayes, Haiti

The vast majority of large Haitian urban areas are coastal cities and draw their water from groundwater. Located downstream from their watersheds, these aquifers are receptacles for multiple downward materials, including oocysts, which threaten the One Health preservation. Cryptosporidiosis infection from livestock is one of the most important health issues. This study investigates the environmental contamination risk posed by Cryptosporidium oocysts from animal faeces in Les Cayes, Haiti, with a particular focus on water resources quality. A total of 129 stool samples from six animal species were collected, with Cryptosporidium coproantigens detected in 27 samples, supporting previous findings from the same locations. Groundwater samples from wells and boreholes also showed significant concentrations of Cryptosporidium oocysts. To better understand oocyst transmission from soil to groundwater, soil samples were analysed for granulometric properties, physico-chemical characteristics, and percolation behaviour. No oocysts were detected in leachates from percolation tests. This may be explained by the soil’s high content of fine particles, which likely interact with and retain oocysts. Environmental transmission was assessed through a tripartite analysis of water, soil, and seasonal climatic factors. These findings contribute to understanding Cryptosporidium transmission pathways and offer a foundation for environmental risk assessment and mitigation strategies in the perspective of a One Health approach.