Outbreak of Swimmer’s Itch in Denmark

Abstract

Swimmer's itch, or cercarial dermatitis, is a waterborne non-communicable skin condition caused by schistosome cercariae released by aquatic snails. Cercarial dermatitis appears worldwide, but may be caused by different trematode species. The itchy maculopapular rash develops on exposed areas of the skin and typically resolves within 1-3 weeks. Shedding of infective larvae from snails is temperature dependent, and high temperatures and sunshine increase the risk of encountering the parasite and becoming infected. The unusually warm spring and summer of 2018 led to an increasing number of reports of the condition in Denmark and established a collaboration between the Department of Dermatology and the Faculty of Health and Medical Sciences, Department of Veterinary and Animal Sciences. This study explored the clinical picture of the disease, and demonstrated the occurrence of infected fresh water snail species in selected Danish water bodies. In conclusion, a risk of swimmer's itch in Denmark was confirmed.