VIII.52 - Fasciolopsiasis

Summary

Fasciolopsiasis is caused by the giant intestinal fluke, Fasciolopsis buski. Discovered in 1843, the organism occurs in China, Korea, Southeast Asia, and parts of India and Indonesia. The adult worm, which has a life-span of only 6 months, attaches itself to the wall of the small intestine of humans. Pigs and dogs can also be infected, and sometimes are important reservoir hosts. Eggs produced by the hermaphroditic adults pass out in the feces and, if they reach fresh water, produce motile larvae that penetrate into the tissues of certain planorbid snails. After two generations of reproduction, another motile form leaves the snail, finds a plant like the water chestnut, water caltrop, or water bamboo, and encysts on it. Humans become infected with cysts by peeling raw fruits of plants with their teeth or eating them uncooked. The disease can become very prevalent in areas where these plants are cultivated with human feces as fertilizer.

Mild infections are often asymptomatic, but flukes can irritate and even ulcerate the intestinal mucosa. Abdominal pain, diarrhea, anemia, and fluid accumulation in the abdomen are common symptoms. Extreme cases can be fatal. Diagnosis is made by discovery of the eggs in the feces. Drug therapy is usually effective. Prevention includes better rural sanitation and control of swine reservoir hosts. Cooking vegetables would also be very beneficial, but drastic changes in long-established culinary habits are unlikely.