[Infection by Strongyloides stercoralis in the county of Safor, Spain]

Strongyloides stercoralis is an endemic nematode in tropical and subtropical regions, but almost unknown in Spain.

In order to know some epidemiological, clinical and analytic features of this infection in our area (La Safor, Valencia), we performed a prospective study for 19 months. Through the search for the parasite in feces of patients with eosinophilia, we identified 37 subjects who were studied at diagnosis and 4 months later.

Thirty-three patients (89%) were currently, or had been agricultural workers, and thirty had worked barefooted and/or had drunk contaminated irrigation water. Twenty-three patients (62%) had a chronic or immunosuppressive diseases, and two of them on steroid treatment, developed a disseminated strongyloidiasis. Thirteen patients (35%) were asymptomatic; the rest had clinical manifestations attributed S. stercoralis, mainly digestive. Two of the patients with disseminated strongyloidiasis also had concomitant bacterial infections by Streptococcus bovis, Streptococcus faecalis and Enterobacter sp. At diagnosis, besides eosinophilia, 86.5% had raised levels of IgE. Four months later treatment, the number of eosinophils was normal and IgE levels significantly decreased. The diagnostic yield of parasitic study of feces was increased with the number of samples examined. Thiabendazole achieved erradication of the parasite in 35 patients, and the other two died because of disseminated strongyloidiasis.

The presence of eosinophilia in patients from rural areas with subtropical climate should raise suspicion about infection by S. stercoralis, which, although sometimes is asymptomatic, may cause systemic bacterial infections in cases of hyperinfestation, specially when glucocorticoid treatment is given.