Map of Distribution of fascioliasis, worldwide, latest year available. Foodborne trematodes are a group of diseases that include the parasites Clonorchis, Opisthorchis, Fasciola and Paragonimus. These parasitic flukes have a complex life cycle involving diverse definitive hosts and one or two intermediate hosts. Foodborne trematodes cause infection in humans via the consumption of contaminated food (raw fish, crustaceans or vegetables). Infection can result in severe liver and lung disease and together these diseases are estimated to cause 2 million life years lost to disability and death worldwide every year.