Echinococcus multilocularis

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]

Overview

Echinococcus multilocularis is a cyclophyllid cestode that, like Echinococcus granulosus, produces hydatid disease in many mammals, including rodents and humans. Unlike E. granulosus, E multilocularis produces many small cysts ("multilocular infection") that spread throughout the infected animal. When these cysts are ingested by a canid, usually by eating an infected rodent, it produces heavy infection with tapeworm adults.

Organism

Echinococcus multilocularis is a cyclophyllid cestode that, like Echinococcus granulosus, produces hydatid disease in many mammals, including rodents and humans. Unlike E. granulosus, E multilocularis produces many small cysts ("multilocular infection") that spread throughout the infected animal. When these cysts are ingested by a canid, usually by eating an infected rodent, it produces heavy infection with tapeworm adults. These adults produce eggs and proglottids that are passed with feces. Small rodents serve as the most common intermediate hosts, but humans that ingest eggs or proglottids may also become infected. A study by Purdue veterinary parasitologists indicated that the disease is spreading throughout the American Midwest, where it was previously rare or nonexistent. Additionally, the disease has extended its range in Europe in the last few decades[2].

Treatment

Antimicrobial therapy

• Echinococcus multilocularis (alveolar cyst disease) treatment

• Preferred regimen: If ≥ 60 kg Albendazole 400 mg PO bid or if < 60 kg Albendazole 15 mg/kg/day PO bid with meals for at least 2 years.
• Note (1): Wide surgical resection only reliable treatment; technique evolving.
• Note (2): Long-term follow up needed to evaluate progression of the lesions.

See Also

• Alveolar hydatid disease