Host-Specific And Seasonal Variations In Prevalence And Intensity Of Strongyloides Spp. Infections In Free-Ranging Herbivores Of Girnar Wildlife Sanctuary, India

Abstract

This study investigates host-specific and seasonal patterns of Strongyloides spp. infections in free-ranging herbivores (Axis axis, Boselaphus tragocamelus, and Rusa unicolor) at Girnar Wildlife Sanctuary, India, using coprological and statistical analyses. From 135 fecal samples collected across monsoon, summer, and winter in 2023, prevalence ranged from 9.1% (A. axis in winter) to 70.0% (B. tragocamelus in winter), with 47.4% showing zero eggs per gram (EPG), indicating significant uninfected proportions. Logistic regression modelled infection presence/absence, revealing 2.63–2.79 higher odds for R. unicolor and B. tragocamelus compared to A. axis (p < 0.05), with robust fit (Hosmer-Lemeshow p = 0.679, McFadden's R² = 0.049). Seasonal effects were non-significant, suggesting host traits dominate over climatic drivers. Intensity, measured as EPG, peaked at 900.0 (IQR = 200.0–1350.0) in R. unicolor during monsoon and 3000 in B. tragocamelus during winter, with Kruskal-Wallis tests confirming host (χ² = 21.30, p < 0.001) and host-season interactions (χ² = 29.24, p < 0.001) as significant, but not season alone (p = 0.238). Dunn’s post-hoc tests identified A. axis as having lower EPG than R. unicolor (p < 0.001) and B. tragocamelus (p = 0.017). A supplementary Poisson model indicated reduced winter rates (rate ratio = 0.414, p = 0.010), likely due to lower larval viability. These findings align with regional studies linking monsoon humidity to transmission peaks and highlight host-specific vulnerabilities, possibly tied to foraging or immunity. Implications include targeted deworming during monsoon for R. unicolor and winter for B. tragocamelus, with future research recommended for molecular diagnostics and immune profiling to enhance conservation strategies in semi-arid ecosystems.