One health investigation of enteric parasites at the human–animal–soil interface in a marginalized peri-urban Philippine community

Enteric parasites remain a significant public health concern in marginalized communities where humans, domestic animals, and the environment interact closely. This study investigated the distribution of intestinal parasites across humans, animals, and soil in Sitio Ibayo, San Mateo, Rizal, a peri-urban Philippine community with limited sanitation and veterinary services. A cross-sectional survey was conducted using stratified purposive sampling. Fresh fecal samples were collected from companion animals (dogs, cats), livestock (chickens), ruminants (water buffalo, cows, goats), and consenting human residents with regular animal contact. High-risk soil from residential yards, playgrounds, and open ranges was also sampled. Parasites were detected using direct smear, Kato-Katz, flotation (mini- and fill-FLOTAC), and sucrose flotation for soil, with morphological identification confirmed by inter-rater agreement. A diverse assemblage of helminths and protozoa was detected across domains. Dogs showed a high prevalence of Ancylostoma spp. (63.9%) and Trichuris spp. (33.8%), while ruminants were predominantly infected with Eimeria spp. (≥ 77%). Among humans (n = 41), Ascaris spp. was most prevalent (56%), especially in children (70%). Soil samples (n = 28) harbored Ascaris spp. (21.4%), hookworm (7.1%), and Toxocara spp. (3.6%). A chord diagram revealed Ascaris spp. as the key “One Health bridge parasite,” occurring across humans, animals, and soil. The detection of shared parasite taxa across domains demonstrates ongoing environmental contamination and exposure risks in Sitio Ibayo. Ascaris spp. plays a central role in sustaining transmission at the human–animal–soil interface. These findings highlight the need for integrated One Health strategies, combining targeted deworming in humans and animals, sanitation improvements, and environmental management, and support the development of Sitio Ibayo as a sentinel site for parasite surveillance in similar peri-urban settings.