Soil-transmitted helminth eggs in public areas of Azores archipelago, Portugal

In the Azores archipelago, data regarding environmental contamination by soil-transmitted helminths (STHs) is inexistent till the moment. The current study aimed to assess the environmental contamination with helminth eggs, in soil samples collected from public parks/gardens and beaches from three islands belonging to the Azores archipelago (Portugal): Faial, Terceira and São Miguel. Between June-December 2024, a total of 37 soil samples were collected from 26 public parks/gardens and 11 public beaches, and processed using the Mini-FLOTAC method to calculate parasites' prevalences and burdens (eggs/oocysts per gram of soil, EPG/OPG). Overall, a total of 35 % of the sampled sites were contaminated with helminth eggs, with the environmental contamination being higher in public parks or gardens (46 %), in comparison with beach areas (9 %). The majority of positive sites were contaminated with Toxocara spp. eggs (30 %), followed by Ancylostomatidae (11 %) and Trichuris spp. (11 %) eggs. São Miguel and Terceira islands presented higher rates of soil contamination, when compared to Faial Island. The overall helminth egg intensity was the following: Toxocara spp. (157 EPG), Trichuris spp. (59 EPG) and Ancylostomatidae (38 EPG). Faial island presented the lowest EPG levels, regarding all parasite species, being Toxocara spp. EPG levels significantly lower than the remaining islands surveyed (p = 0.02). The present study provides new and relevant data concerning environmental contamination by STHs with zoonotic potential in the Azores archipelago, and revealed that the analysis of soil samples is an important approach to be included in integrated pet parasite control programs.