Fish Tape Worm Disease

FISH TAPE WORM DISEASE

EPIDEMIOLOGY

Fish tapeworms are found wherever raw, pickled, or undercooked freshwater fish from fecally contaminated lakes and streams is eaten by humans. Other fish-eating mammals may also serve as reservoir hosts. Human infections have been described in the Baltic and Scandinavian countries, Russia, Switzerland, Italy, Japan, China, the South Pacific, Chile and Argentina. The worm, brought to North America by Scandinavian immigrants, is now found in Alaska, Canada, the midwestern states, California, and Florida. It was shown recently that infectious plerocercoid larvae may develop in anadromous salmon, and human cases have been traced to the ingestion of fish freshly taken from Alaskan waters. The increasing popularity of raw fish dishes such as Japanese sushi and sashimi may lead to increased prevalence of this disease in the United States. Among Ontario In-dians, infection is acquired by eating fresh salted fish. Even when fish is appropriately cooked, individuals may become infected by sampling the flesh during the process of preparation.