Farming occupation and strongyloidiasis. Case control study

Background, In the last few years, Strongyloides stercoralis has been repea tedly recovered from indigenous farmers in the Safer area (Valencia Communi ty). The relationship between the different occupational activities, mainly farming, and the presence of strongyloidiasis was investigated. Patients and methods. A paired case-control study was designed. The investi gation was conducted at Oliva Centro de Salud, from October 1997 to October 1999. Diagnosis was established when Strongyloides stercoralis was observe d in any of the three serial fecal samples requested when eosinophilia was observed in the hemogram. Controls were persons matched by sex and age (+/- 5) years, with no eosinophilia in the hemogram and in whom the presence of the parasite was excluded in fecal samples. Results. Participants in the study were 47 cases and their respective contr ols. Each group included 39 (83%) men and 8 (17%) women. Forty-five cases ( 95%) and 42 controls (89%) had been born in Safer. Only two cases had trave lled to endemic areas. Farming was the main activity in 32 (68%) cases and 31 (66%) controls. The only occupational activity which showed influence on strongyloidiasis was w orking in ricefields, with an OR of 2.97 (95%, CI: 1.16-7.71). Dermatologic symptoms were significant for pruritus, OR 7.39 (95% CI: 2.29-27.60). One case with hyperinfection and another with larva currens were diagnosed. Conclusion. In our area, working in ricefields and chronic pruritus are ass ociated with chronic strongylodiasis.