Soil-transmitted helminths detected from environmental samples in a campus of southern Brazil

Soil harbours enormous biodiversity, essential for maintaining environmental and human health. However, soil can also be a reservoir of various parasitic pathogens, such as soil-transmitted helminths (STH). We evaluated the presence of STH (e.g., hookworms, roundworms and whipworms) in soil samples collected at twenty points within the perimeter of Campus do Vale (a university campus belonging to the Federal University of Rio Grande do Sul - UFRGS), during 2022 winter season. Considering the One Health perspective, human, animal and environment-related data from each sampling point were collected. All soil samples showed nematode larvae, representing natural components of soil biodiversity. Considering STH eggs, 35% (n = 7) of soil samples showed hookworm eggs (e.g., from Necator americanus or Ancylostoma duodenale), 10% (n = 2) showed roundworm (Ascaris lumbricoides) eggs, and 5% (n = 1) showed whipworm (Trichuris trichiura-like) eggs. Of note, 10% of the sampling points showed the presence of rhabditiform hookworm larvae, 5% showed Strongyloides stercoralis rhabditiform larvae and 5% had the presence of filariform hookworm larvae, indicating a risk of human percutaneous infection. The significant people circulation in Campus do Vale, in association with other environment-related factors, help to explain the prevalence of STH observed in this study.