(2) Chinese liver fluke. Loss of appetite, diarrhea, fever, and a sensation of
abdominal pressure are early symptoms. Later, there may be bile duct obstruction,
sometimes producing jaundice, followed by cirrhosis, enlargement and tenderness of
the liver and progressive ascites and edema.
d. Treatment. There is no satisfactory specific drug, and treatment is mainly for
the symptoms. If a drug is given, these are the choices.
(1) Sheep liver fluke. The drug of choice is bithionol because of its low
toxicity. Emetine hydrochloride can be used if bithionol is not available. A drug less
toxic than emetine is dehydroemetine.
(2) Chinese liver fluke. Two drugs are beneficial although they do not cure
the disease: chloroquine phosphate and hetol. The newest drug of choice is
praziquantel.
3-11. INTESTINAL FLUKES
The intestinal fluke Fasciolopsiasis is a parasite found in the large intestine. It is
commonly found in humans and pigs in China, Taiwan, Southeast Asia, and India.
a. Life Cycle.
(1) The life cycle begins when eggs shed in stools reach the water. They
hatch in the water and become free-swimming larvae that penetrate and then develop in
the flesh of snails. Cercariae (the final larval stage of the parasite (free-swimming with
body and tail) leave the snails and encyst on various water plants.
(2) When humans eat these plants uncooked (usually water chestnuts or
other caltrops), humans become infected with the disease. Adult flukes live in the small
intestine where they attach themselves to the mucosa or bury themselves in mucous
secretions. Flukes mature in about three months.
b. Signs and Symptoms. Gastrointestinal irritation is present in all infections
except light infections. The following symptoms occur in severe infections:
(1) Early signs and symptoms. There may be cramping epigastric and
hypogastric pains, diarrhea, intermittent constipation, anorexia, intestinal stasis, and
nausea.
(2) Later signs and symptoms. Edema (abnormally large amounts of fluid in
the intercellular tissue spaces) in the face and ascites (effusion and accumulation of
serious fluid in the abdominal cavity) are later symptoms. Cachexia (general ill health
and malnutrition) or intercurrent infection may eventually cause death.
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