metagonimiasis

Metagonimiasis is a disease caused by an intestinal trematode, most commonly Metagonimus yokagawai, but sometimes by M. takashii or M. miyatai. The metagonimiasis-causing flukes are one of two minute flukes called the heterophyids. Metagonimiasis was described by Katsurasa in 1911–1913 when he first observed eggs of M. yokagawai in feces (date is disputed in various studies). M. takahashii was described later first by Suzuki in 1930 and then M. miyatai was described in 1984 by Saito.

== Signs and symptoms == The main symptoms are diarrhea and colicky abdominal pain. Because symptoms are often mild, infections can often be easily overlooked but diagnosis is important. Flukes attach to the wall of the small intestine, but are often asymptomatic unless in large numbers. Infection can occur from eating a single infected fish source. Peripheral eosinophilia is associated especially in early phase. When present in large numbers, can cause chronic intermittent diarrhea, nausea, and vague abdominal pains. Clinical complaints can also include lethargy and anorexia. In acute metagonimiasis, clinical manifestations are developed only 5–7 days after infection. Heavy infection has also been associated with epigastric distress, fatigue, and malaise.