The adult worm is usually 15–30cm long and 3–6mm thick. Human small intestine is the permanent host . After ingestion of infected eggs, larvae are released in the duodenum and pass through the duodenal wall to the bloodstream. In the lung, they infiltrate in the alveoli, migrate over the bronchial three and trachea, are swallowed and fixed in the jejunum [1;2;4].
In the presence of high overload of worm infestation or other condition that affect the small intestine motility, the worm can penetrate the ampulla of Vater and enter in the biliary and pancreatic ducts [1;2]. Presence in the cystic duct and gallbladder is rare, representing approximately 2% of the hepatobiliary ascariasis (HBA) cases .
There is a female prevalence (3:1) and prior biliary surgery, pregnancy and factors that alter the environment around the worm can predispose to HBA .
Usually presents in mid-thirties with biliary colic, acute cholangitis, acute cholecystitis, pancreatitis, hepatic abscess, and, rarely, with hemobilia [2;4].
Ultrasound findings include a long, coiled echogenic structure, without posterior shadowing, an echogenic strip with central anechoic line, a gallbladder with a septate appearance caused by an echogenic structure, associated with random movements of these structures .
Endoscopic retrograde cholangiograms (ERCP) and MR cholangiograms show intraductal worms as long tubular filling defects in the bile duct or gallbladder .
HBA usually resolves after conservative treatment with oral anthelminthic. When conservative treatment fails to eradicate the infection, or the worms are dead or intrahepatic or there are concomitant biliary stones, ERCP and/or surgery are the treatments of choice. Gallbladder ascariasis usually requires cholecystectomy .
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 Biliary Infections: Spectrum of Imaging Findings and Management Journal: RadioGraphics, 2009, Vol. 29, No. 7. Author: Catalano O, et al
 Hepatic and Biliary Ascariasis Journal: J Glob Infect Dis, 2014, 6(2): 65–72.. Author: Anup K Das
 Hepatobiliary and pancreatic ascariasis in India Journal: Lancet, 1990, 23;335(8704):1503-6. Author: Khuroo MS, et al
 Parasitic Diseases of the Biliary Tract Journal: AJR, 2007, 188: 1596-1603. Author: Lim J, et al
 Sonographic findings in gallbladder ascariasis Journal: J Clin ultrasound, 1992, 20(9):587-91. Author: Khuroo MS, et al
 Gall bladder ascariasis Journal: Ann Trop Med Public Health, 2013, 6:489-90. Author: Hajong R, et al