Cholangitis Caused by Parasitic Infection

A 41-year-old man complained of upper abdominal pain and malaise of several months duration. He had emigrated to the United States from Korea 5 years earlier.

The only abnormality Drs Lucia C. Fry and Klaus E. Mönkemüller of Chandler, Ariz, noted during the physical examination was pain on palpation of the right upper quadrant. The alkaline phosphatase and bilirubin levels were 380 U/L and 2.5 mg/dL, respectively; aminotransferase levels were mildly elevated.

A CT scan of the abdomen revealed dilated intrahepatic ducts. An endoscopic retrograde cholangiopancreatogram demonstrated an abnormal biliary tree; the common bile duct and both intrahepatic ducts appeared tortuous, with multifocal strictures, irregularities, and dilations that gave a beaded appearance (A). This is the classic radiologic finding in patients with sclerosing cholangitis. Both intrahepatic biliary ducts had multiple small filling defects that suggested stones and debris. Microscopic examinations of aspirated bile and stool specimens revealed multiple eggs of Clonorchis sinensis (B).

The Chinese liver fluke, C sinensis, is endemic to large areas of China, Japan, Korea, and Vietnam. Human infection results from the ingestion of raw or undercooked freshwater fish that contain the encysted metacercariae. Adult worms live in the bile ducts, where they initially localize distally, just beneath the capsule of the liver. The worm, or fluke, ranges from 1 to 2.5 cm in length and 0.3 to 0.5 cm in diameter. In patients with massive infection, the worms inhabit most of the bile ducts and may even be found in the gallbladder and pancreatic duct.

These organisms can live as long as 30 years. Adult worms may be discovered only at autopsy or, rarely, upon surgical removal of the distal biliary tree during an hepaticojejunostomy. As many as 2400 eggs per worm can be found daily in a patient's feces or bile. Diagnosis is made by recovery of the eggs from stool, from duodenal aspirates, or from the enteric capsule.

Most infections are mild and asymptomatic. Symptomatic early infections occur with ingestion of large numbers of metacercariae in a short time. The acute phase lasts less than 1 month and may be associated with fever, diarrhea, epigastric pain, anorexia, enlargement and tenderness of the liver and, occasionally, jaundice. Generally, eosinophilia is present; leukocytosis may occur. After the acute symptoms subside, patients with chronic low-grade infection typically are symptom- free, unless they are repeatedly reinfected.

Repeated infection over many years results in a heavy worm burden. This can lead to a functional impairment of the liver, which is secondary to localized biliary obstruction and may be aggravated by intrahepatic stones, cholangitis, and multiple liver abscesses.

The failure of praziquantel(-the drug of choice for C sinensis infection- to resolve this patient's disease was attributed to his severely fibrotic biliary tract. He was given long-term antibiotic prophylactic therapy to prevent recurrent bacterial cholangitis and ursodeoxycholic acid( to improve cholestasis. The patient is asymptomatic 1 year after presentation.