Prediction of helminthiases in travellers and migrants with eosinophilia: a cohort study.

Objectives: The aim of this study was to determine predictors for helminthiasis among travellers and migrants with eosinophilia for which a visit to tropical regions or endemic regions for common helminthiasis had been registered.

Methods: A retrospective cohort study was performed using electronic health records of 23 905 patients with eosinophilia (January 2011-August 2021) at Karolinska University Hospital, Stockholm, including patients tested for helminthiasis with a registered stay in a helminth endemic region. Outcomes were diagnosis of any helminthiasis and diagnosis of schistosomiasis and strongyloidiasis. Multivariable logistic regression was used to assess associations between potential predictors and helminthiases with a backwards stepwise elimination approach until a predictive model was reached in which each variable had a p value < 0.15.

Results: Of 1112 eligible patients with eosinophilia and documented stay in endemic regions, 219 (19.7%) had been diagnosed with helminthiasis, most frequently schistosomiasis (n = 95, 43.4%) and strongyloidiasis (n = 64, 29.2%). A stay in Sub-Saharan Africa (SSA) (OR, 8.2; 95% CI, 2.44-27.56), malaise and fatigue (OR 2.65; 95% CI, 0.77-9.09), and high-grade eosinophilia >1500 cells/μL (OR 2.26; 95% CI, 1.54-3.32) were the most important predictors for any helminthiasis (area under the curve [AUC], 0.77; 0.74-0.80). An SSA origin (AUC, 2.97; 1.11-7.95), malaise and fatigue (AUC, 5.48; 1.13-26.63), and high-grade eosinophilia (AUC, 1.53; 0.86-2.71) were predictors for schistosomiasis (AUC, 0.74; 0.70-0.77); whereas SSA origin (AUC, 5.68 (3.04-10.59)), itching symptoms (AUC, 5.05; 1.32-19.36), and high-grade eosinophilia (AUC, 2.42; 1.33-4.41) were predictors for strongyloidiasis (AUC, 0.73; 0.69-0.76).

Discussion: A stay in an endemic region, specifically SSA, having high-grade eosinophilia, and malaise and fatigue were the most important predictors for helminthiasis. Itching was an additional predictor for strongyloidiasis.