Imported human Schistosoma japonicum: A report on two cases in Filipino migrants present in Italy and a systematic review of literature

Abstract

BackgroundSchistosoma japonicum is endemic in the Philippines, China, and Indonesia, and is the third-most common schistosoma species. The infection can be asymptomatic for years but, if left untreated, can lead to irreversible complications. MethodWe report the results of a systematic review of the literature on imported S. japonicum infection and describe two previously unpublished cases diagnosed in Filipino migrants in Italy. ResultsTwenty-five imported cases of S. japonicum schistosomiasis were retrieved. All patients but one were migrants. Most subjects acquired the infection in Philippines (n = 18, 72%). Median age at diagnosis was 46 years. Median period of residence in non-endemic countries before diagnosis was 14.5 years. Cases of prevalent hepatosplenic involvement were 10 (40%), those with prevalent intestinal involvement were 10 (40%), whereas five (20%) had overlapping manifestations. Ten patients suffered from cirrhosis; two underwent liver transplantation. Three patients presented with acute abdomen due to intestinal complications, leading to explorative laparotomy. In all cases, but one, the diagnosis was based on a histological examination of biopsy specimen, revealing S. japonicum ova. Seventeen patients were treated with praziquantel, and in three of them, possible treatment failures occurred. ConclusionsS. japonicum infection is uncommonly reported in non-endemic areas, but is probably underestimated because of a low threshold awareness of clinicians and unavailability of specific diagnostic tools. Viable S. japonicum adults may persist for decades, indicating that migrants or travellers previously exposed in areas with high-risk areas can harbour viable worms and deserve treatment.