Narendra Nath Mukhopadhyay

By Narendra Nath Mukhopadhyay

Ascaris lumbricoides (Round Worm) is the most common human helminth with a world wide distribution. Incidence of ascariasis remain very high in the tropical and sub tropical countries with poor sanitation, personal hygiene, and rural areas where defaecation in open place is still a common practice. Ascariasis is classified as a neglected tropical disease. Infections have no symptoms in more than 85 percent of cases specially if the number of cases are small. Pathogenecity and clinical features are either due to migrating larvae or due to adult worms. Larval migration may lead to allergic reactions, ascaris pneumonia. Adult worms are often responsible for nutritional deficiencies, toxic effects due to hypersensitivity &mechanical effects leading to intestinal obstruction. Ectopic ascariasis can lead to acute biliary obstruction, cholangitis, acute pancreatitis, acute obstructive appendicitis and peritonitis due to perforation of an intestinal ulcer or break down of a post operative suture line. Medical therapy with Albendazole is the first line drug ascariasis can be eliminated by preventing faecal contamination of soil. Advancement in recombinant protein technology may provide first step in discovery of Ascaris vaccine as well as pan helminthic Vaccine. This chapter is a updated review of ascariasis.

Part of the book: Roundworms

By Narendra Nath Mukhopadhyay

Common Name: Dog Tapeworm. Echinococcus granulosus is most prevalent and causes cystic hydatid disease. Echinococcus multilocularis is uncommon and responsible for alveolar hydatid disease. Hydatid disease is a significant health problem worldwide. It is a zoonosis. Adult worm lives in the small intestine of dog and rarely wolf and fox. Dog is the optimal definitive host. The larval stage (hydatid cyst) is found in herbivorous animal like sheep, goat, cattle. Man is the accidental intermediate host. Echinococcal infection occurs through ingestion of eggs that are passed through the feces of definitive host. After ingestion of eggs, the egg liberates embryo which passes through the intestinal mucosa in the portal circulation. Right lobe of the liver is the commonest site for liver hydatid cyst. The cyst wall consists of pericyst, ectocyst and endocyst. Endocyst or the germinal layer is the site of asexual reproduction giving rise to brood capsule and scolices. Symptoms mainly due to pressure effect. Rarely fatal anaphylaxis may occur due to spontaneous rupture or during surgery. USG and CT is the most valuable imaging technique. Serology is an adjunct to diagnosis. Classification of hydatid cyst by Gharvi et al. into five types based on sonographic analysis. Treatment modalities include chemotherapy, percutaneous treatment and surgery.

Part of the book: Echinococcosis