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 visto 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 to 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 1,112 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 [0.77-9.09]) and high-grade eosinophilia >1500cells/μl, (2.26, [1.54-3.32]) were the most important predictors for any helminthiasis (AUC: 0.77 [0.74-0.80). A SSA origin (2.97 [1.11-7.95]), malaise and fatigue (5.48 (1.13-26.63) and high-grade eosinophilia, (1.53, [0.86-2.71]) were predictors for schistosomiasis (AUC: 0.74 [0.70-0.77]; whereas SSA origin (5.68 [3.04-10.59]), itching symptom (5.05 [1.32-19.36], and high-grade eosinophilia (2.42, [1.33-4.41]) were predictors for strongyloidiasis (AUC: 0.73 [0.69-0.76]).

Conclusions: 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.