Fascioliasis: sonographic abnormalities of the biliary tract and evolutionafter treatment with triclabendazole

Diagnosis of infection with the liver fluke Fasciola hepatica is usually di fficult. Ultrasonography (US) might be a useful diagnostic alternative, and we assessed the value of sequential US in the diagnosis and monitoring of fascioliasis in 76 patients at baseline and for 60 days after treatment wit h triclabendazole. At baseline, biliary abnormalities were observed in 52 p atients. Crescent-shaped parasites were seen in 11 patients; in 2 cases par asites were spontaneously moving and in 4 patients parasites were motionles s. Postprandial examination revealed parasites adhering to the gallbladder wall in a further 5 cases. In 3 further cases, gallbladder contents were mo bile but did not sediment downwards after patients changed position. Non-sp ecific abnormalities were: impaired gallbladder contractility (n = 23), gal lbladder tenderness (n = 19), debris (n = 6), calculi (n = 5), wall thicken ing (n = 2) and bile duct dilatation (n = 12). During day 1-7, Fasciola-lik e crescents in the gallbladder or passing through the bile duct were detect ed in another 15 patients, impaired gallbladder contractility in 16, gallbl adder tenderness in 16, and bile duct dilatation in an additional 28 patien ts. Thirty-two patients with these US abnormalities experienced colic-like abdominal pain accompanied by increased alkaline phosphatase in 25 cases. D uring day 30-60, abnormalities regressed completely in 45 patients; 2/6 tri clabendazole failures were evident by detection of living parasites. Biliar y tract abnormalities are frequently observed by US, but the detection-rate of Fasciola hepatica is disappointingly low despite the parasite's relativ ely large size. US findings must therefore be interpreted together with oth er clinical measurements. The visualization of parasites being expelled thr ough the dilated common bile duct allowed the causal interpretation of post -therapeutic abdominal pain and increase of liver enzymes. When triclabenda zole is given on suspicion, visualization of worm expulsion and bile duct d ilatation by US may be used to confirm diagnosis.