Modern techniques in the diagnosis and treatment of gastrointestinal and biliary tree parasites.

Parasitic infestations are endemic in tropical and subtropical areas, but rarely occur in temperate zones, and are imported by tourists, immigrants and expatriates. Gastrointestinal and biliary tree parasites are the commonest helminthics in humans. Previously these were diagnosed only by stool examinations, but recently other diagnostic techniques have been used. These include fibreoptic endoscopies for upper or lower gastrointestinal tract and biliary tree. Endoscopy plays an important role in diagnosis, treatment and follow-up as in gastric anisakiasis, chronic giardiasis, strongyloides, hepatosplenic and chronic intestinal schistosomiasis. ERCP is diagnostic in biliary tree obstruction due to parasites or associated stones or cholangiocarcinoma; worm extraction will lead to biliary decompression. Endoscopic instillation of drugs such as mepa-crine in chronic giardiasis, piperazine in biliary ascariasis and hypertonic saline in a ruptured hydatid liver cyst. Imaging techniques, such as barium studies, ultra-sound, CT and MRI, play an essential part in investigations and follow-up in parasitic disease. Therapeutic techniques under ultrasound or CT guidance for amoebic liver abscess or recent percutaneous drainage of hydatid cyst of the liver have been done successfully.