Rare human infection with the trematode Echinochasmus japonicus in Lao PDR

Food-borne trematodiases are often neglected although millions of people are affected and these zoonotic diseases are emerging in some parts of the world. Humans acquire an infection through consumption of the second intermediate hosts (e.g. freshwater fish) that harbour the metacercariae of the parasite. Here, we report the first three cases of Echinochasmus japonicus infection in Lao PDR. Adult E. japonicus flukes were recovered from a woman (age: 37 years) and two men (age: 42 and 75 years) following treatment with praziquantel (single oral dose of 40 mg/kg) and purgation (45 ml monosodium sulphate). All three individuals were infected with two other species of trematodes concurrently, namely Opisthorchis viverrini and Haplorchis taichui. The two male patients moreover harboured Prosthodendrium molenkampi and Phaneropsolus bonnei trematodes. All three cases suffered from diarrhoeal episodes and other gastro-intestinal discomforts in the month preceding praziquantel administration and purgation. The frequent consumption of raw or insufficiently cooked freshwater fish and other aquatic products is the root cause of acquiring rare zoonotic infections such as E. japonicus.