Schistosomiasis is increasingly encountered among travellers returning from the tropics and is known for its focal endemicity, associated with the presence of the snail intermediate host in fresh water. Because schistosomiasis in travellers is often atypical or asymptomatic due to the low intensity of infection, many infections likely go undiagnosed and will develop into chronic schistosomiasis. Conventional treatment of schistosomiasis in travellers with praziquantel 40mg/kg daily dose is known for its modest success rate. Diagnosis of schistosomiasis relies on egg detection, which has a poor sensitivity in low burden infections, or serology, which is inadequate to monitor cure. The department of parasitology of the Leiden University Medical Center has developed a novel diagnostic test based on the up-converting phosphor technology (UCP) to detect circulating anodic antigen (CAA). This test can be performed on serum and urine to detect low intensity schistosomiasis infections and confirm cure after praziquantel treatment. This study will assess the performance of UCP-CAA in travellers with high-risk water contact.