Schistosomiasis in Norwegian students after travel to Africa.

BACKGROUND

Schistosomiasis is a tropical infectious disease in which early diagnosis and treatment can prevent serious illness. This study examined the incidence and diagnosis of schistosomiasis in Norwegian exchange students who had been exposed to freshwater in Africa.

MATERIAL AND METHOD

Students (n = 318) from Bergen and Oslo who had travelled to Africa as part of an exchange programme in the period 2003-18, were contacted and included in the study if they had been exposed to freshwater during their stay. A routine workup was performed comprising Schistosoma antibody testing, microscopy and/or PCR analysis of urine and faeces, dipstick urinalysis, and blood samples for analysis of eosinophilic granulocytes, creatinine and total IgE. Time, place and type of exposure were recorded in a questionnaire, along with symptoms.

RESULTS

Schistosoma antibodies were detected in 46 (30 %) of the 151 students included in the study. None of the seropositive individuals had eggs detected in their urine or faeces, and none had eosinophilia. Two students reported cercarial dermatitis, while one had symptoms consistent with acute schistosomiasis. Rafting was the only form of freshwater exposure reported by 22 (55 %) of the 40 seropositive individuals.

INTERPRETATION

A large proportion of the students who had been exposed to freshwater were diagnosed with schistosomiasis. The majority reported no symptoms. Rafting was the most common form of exposure. All were diagnosed by serologic tests, while other routine diagnostic tests for schistosomiasis proved less useful. Serological analysis should be the preferred form of testing for the diagnosis of schistosomiasis in travellers.