Schistosomiasis is currently the second most common parasitosis in the world, following malaria, in terms of morbidity and mortality.1 It is thought that, as a result of the increase in international travel and immigration from endemic regions, the incidence of imported schistosomiasis in France is rising. There are few data on imported schistosomiasis, especially in children. International guidelines recommend that adult migrants from endemic areas should be systematically screened for schistosomiasis, regardless of whether they are symptomatic or not.2,3 However, the lack of studies on paediatric imported schistosomiasis means that there are no specific guidelines on screening children. The objectives of the present study were to estimate the prevalence of imported schistosomiasis in at-risk children in the greater Paris region of France and to compare diagnostic methods.
All children at risk of schistosomiasis and who had undergone consultations in four hospitals in the greater Paris region between June 2017 and June 2018 were prospectively included. Clinical and laboratory data were collected after a consent form and an information leaflet were given to legal guardians, and to the child using a translator if needed. Unaccompanied minor refugees signed their consent in the absence of legal guardians (considered emancipated minors). This research was declared to the French Commission Nationale Informatique et Libertés according to the French law relating to computers, files, and freedoms (CNIL). Urine and faeces samples were screened using microscopy, a point-of-care circulating cathodic antigen,4 and a real-time polymerase chain reaction assay.5 Serum samples were screened using a Western blot assay, an ELISA, an indirect haemagglutination assay, and an immunochromatographic assay.6 The Western blot assay and the microscopy analysis were the reference methods used to estimate the prevalence of schistosomiasis. A latent class model was used to evaluate each method’s diagnostic performance.7
A total of 114 children were included (male-to-female sex ratio: 2:9; mean age: 13.2 years). Most of the children were newly arrived migrants from sub-Saharan Africa. The prevalence of schistosomiasis was 26.3% and half of these positive patients were asymptomatic. In a latent class model analysis, the ELISA and the Western blot assay had the same sensitivity (83%) and specificity (99%). The serum immunochromatographic assay also performed well (sensitivity: 100%; specificity: 89%).
The high prevalence of imported schistosomiasis among at risk children in the greater Paris region confirms the need for systematic screening. A serum immunochromatographic assay appears to be the most cost-effective screening method.