Seroprevalence of Strongyloides stercoralis Infection and Its Risk Factors in Pregnant Women Referred to Al-Zahra Hospital in Guilan Province, North Part of Iran: A Cross-Sectional Study From 2024 to 2025.

Abstract

Background: In immunocompromised individuals, strongyloidiasis may progress to hyperinfection syndrome or disseminated disease. To date, the death of a pregnant woman infected with Strongyloides stercoralis has been reported. Chronic cases carry a risk of malnutrition, especially among vulnerable populations like pregnant women and children. Pregnancy-related immunosuppression increases susceptibility to severe strongyloidiasis. This study assesses strongyloidiasis seroprevalence in pregnant women at Al-Zahra Hospital, Guilan Province.

Materials and methods: This cross-sectional study (September 2024 to February 2025) randomly selected 384 pregnant women referred to Al-Zahra Hospital, Rasht. After consent, blood (all) and permitted stool samples plus symptom questionnaires were collected. Serum was tested for anti-S. stercoralis IgG antibodies using ELISA (NovaLisa). Stool underwent parasitological examination (direct smear, formalin-ethyl acetate concentration method, and nutrient agar plate culture [APC]). SPSS v25 analyzed data using Fisher's exact test.

Results: The study enrolled pregnant women (gestational age: 1-8 months) aged 15-48 years. The seroprevalence of strongyloidiasis (anti-S. stercoralis IgG antibodies) was 2.6%. Six of these individuals, who provided stool samples, also tested positive by parasitological examination. No significant associations (p > 0.05) were observed between infection and factors including vegetable washing practices, residential location (urban/rural), education level, occupational exposure, soil contact, clinical symptoms, animal contact, or hypereosinophilia. However, a significant association (p < 0.05) was identified between strongyloidiasis and underlying conditions, with gestational diabetes present in 30% of patients.

Conclusion: The overlap of gastrointestinal, respiratory, and hematological symptoms with pregnancy contributes to the underdiagnosis of strongyloidiasis. Early respiratory symptoms are hormonally driven, whereas persistent later symptoms suggest infection (50% strongyloidiasis cases here). Preconception S. stercoralis serology and hygiene/animal-contact education are recommended.