Is strongyloidiasis currently autochthonous in Croatia? A retrospective study.

BACKGROUND Autochthonous human infections with Strongyloides stercoralis have been well documented in many European regions. By exploring patients' data, we aimed to find elements for its current endemicity in Croatia. METHODS This retrospective descriptive study analysed epidemiological and clinical data of patients treated for strongyloidiasis from January 2010 to May 2019 at a teaching hospital in Zagreb, Croatia. The diagnosis was made by direct methods using light microscopy and/or serology. RESULTS Among 65 patients with strongyloidiasis, 60% were men, and 78.5% were 50-79 y of age. The sensitivity of the examination of three stool samples after concentration, saline provocation and serology was 26.2, 80.7 and 86.2%, respectively. Clinical presentation included asymptomatic patients with eosinophilia (41.5%), chronic symptomatic infection (33.8%), acute infection (18.5%) and hyperinfection (6.2%). Twenty patients (30.8%) were immunosuppressed; among four of whom developed hyperinfection, two died. Initially 71.7% of patients were treated with albendazole and 13.3% with ivermectin, with an equal parasitological cure rate (72.2% and 75%; p=0.09). In 11 patients, acute infection was autochthonous in its origin. CONCLUSIONS Strongyloidiasis is currently endemic in Croatia and immunosuppressed travellers to this region should be advised to take precautions. Patients undergoing immunosuppression and organ donors from Croatia should be screened.