Contribution à l’évaluation de la contamination environnementale par les géohelminthes dans le sud de la wilaya de Sétif

Abstract

This study was designed to detect possible parasitic contamination by geohelminths in soil, water, and raw vegetables marketed in the Aïn Azel region. A total of 30 soil samples were collected from three different sites, 20 water samples were taken, in addition to the purchase of 30 fresh vegetable samples, including lettuce and coriander, during the period from March to May 2026. All samples were examined under a microscope after the application of specific laboratory techniques for parasite detection. The overall prevalence of parasitic contamination reached 23.3% in soil samples and 35% in water samples, while no parasitic contamination was recorded in vegetables (0%). Laboratory analyses revealed that the contamination was limited to the presence of two main types of geohelminths. Ascaris sp. was the most predominant, with rates of 16.67% in soil and 20% in water, followed by Strongyloides sp. with 6.67% in soil and 15% in water. It was observed that the prevalence of parasitic contamination varies according to the source of the samples: the highest prevalence was recorded in agricultural fields (60%), followed by areas near households (10%), while surface waters from wadis showed a high contamination rate of 70%. In contrast, the results showed a complete absence of parasitic contamination in drinking water. In parallel with these environmental indicators, the retrospective epidemiological analysis of data from the Public Establishment of Proximity Health Care of Aïn Azel for the year 2025 revealed active transmission of geohelminthiases. Ascariasis was predominant with a frequency of 63%, followed by trichocephalosis with 37%. Finally, it can be concluded that parasitic contamination in the Aïn Azel region is mainly concentrated in agricultural fields and wadis, which constitute the main reservoirs for the dissemination of infective stages, while vegetables and drinking water remain safe and clean. This epidemiological situation calls for the implementation of integrated strategies, including strengthening epidemiological surveillance, improving sanitation networks, and protecting water sources from pollutants.