The roundworm Strongyloides stercoralis in children, dogs, and soil inside and outside a segregated settlement in Eastern Slovakia: frequent but hardly detectable parasite

A comparative study was carried out to evaluate the Strongyloides stercoralis infections in children and dogs inside and outside the segregated settlement in Medzev, Eastern Slovakia, and a survey of the soil within the settlement was included. Applying the Koga agar plate (KAP) culture method and microscopy examination of stool samples collected from 60 Roma and 21 nonRoma children, no larvae of S . stercoralis were detected but eggs of three nematodes ( Ascaris lumbricoides , Trichuris trichiura , and Enterobius vermicularis ) and cysts of two protozoan endoparasites ( Giardia duodenalis and Cryptosporidium spp.) were often found. However, immunoenzymatic assay (ELISA) for the evidence of IgG antibodies against S . stercoralis showed 33.3% seroprevalence in Roma children and 23.8% prevalence in children from the majority population, attending the same school. Eosinophilia was regularly present in children with exclusive infection of S . stercoralis (eight cases) as well as in individuals suffering from mixed infections of S . stercoralis and some of the above listed parasites (16 cases); high eosinophil counts sometimes, but not always, occurred in parasitized children lacking S . stercoralis antibodies. A comparison of S . stercoralis in dogs from the settlement (40 dogs) and from a distant dog shelter (20 dogs) did not reveal remarkable differences: the direct microscopy of faecal samples revealed rhabditiform larvae in 13.3% of the dogs from the settlement (4/30) and in 10.0% of the dogs from the shelter (2/20). Out of blood samples collected from the second dog group, 55% of the dogs contained antibodies against S . stercoralis . In the soil collected from 14 various locations within the settlement, S . stercoralis larvae were observed in two samples (14.3%); however, 13 samples (92.9%) were positive for human or dog endoparasites of the genera Ancylostoma , Ascaris , Toxocara , Toxascaris , Trichuris , and Hymenolepis .