Eosinophilia as a diagnostic window for strongyloidiasis: seroprevalence insights from an endemic region

INTRODUCTION: Eosinophilia is a recognized hematological marker associated with helminthic infections, including strongyloidiasis which is caused by Strongyloides stercoralis. This case-control study, conducted in Mazandaran province from 2022 to 2023, aimed to determine and compare the seroprevalence of S. stercoralis infection between individuals with eosinophilia and healthy controls without eosinophilia. The ELISA test by a commercial kit was used for serological detection of anti-S. stercoralis IgG antibodies, and data were analyzed using SPSS software (version 23). RESULTS: There was analyzed 184 samples, divided into two groups, with and without eosinophilia, with 92 individuals each. In these groups, 36.96% (34/92) and 7.61% (7/92) were positive for anti-S. strongyloides IgG antibodies, respectively, which revealed a strong association (OR = 7.12, 95% CI [3.82, 13.27], P < 0.001) between S. stercoralis antibodies as eosinophilia, confirming eosinophilia as a important predictor of S. stercoralis exposure. Subgroup analyses revealed that males, farmers, individuals aged > 41 years, those with a history of soil contact, and residents of rural areas exhibited higher seroprevalence rates of S. stercoralis. The findings suggest that screening individuals with eosinophilia for anti-S. stercoralis IgG antibodies may improve diagnosis in endemic area.