Parasitic Helminths And their Control Helminthes are the

Parasitic Helminths And their Control • Helminthes are the animals belonging to phyla Platyhelminthes and Nemathelminthes. • Soft bodied, dorso-ventrally flattened and bilaterally symmetrical. • Classes Trematoda Cestoda Nematoda

Trematoda • • Leaf like animals, both ecto and endoparasite. Suckers or hooks for attachment. Branched alimentary canal Includes flukes parasite on man and other animals.

Fasciolopsis buski (flatworm) • Large intestinal fluke of man, dog, and pigs, quite common in india and china. • 20 -70 mm in length and 8 -20 mm breadth. • Ventral sucker is larger and close to anterior sucker. • Pharynx is small, oesophagus short and caeca long and nondiverticulate. • Gonads occupy posterior region of body. • Disease : Adult worms cause erosion of the lining of the digestive tract, resulting in the bleeding and pain in the intestine. • It may lead to vomiting and diarrhoea.

• Prevention and control: Antihelminthic drugs viz, Hexylresorcinol and crystalloids should be used for treatment.

Opisthorcis sinensis (Chinese liver fluke) • Important parasite in the bile duct of man in oriental region. • Bile duct of man, cat, dogs • First intermediate host is snail and second is fish. • 10 -25 mm in length and 2 -4 mm in width

• Diseases: when the no. of adult flukes increases in the bile duct wall thickens causing cirrhosis. • In chronic infection of fluke, death of persons have been observed. • Prevention and Control: Fresh water fishes should be cooked properly before eating. Chloroquine and gentian violet are used to cure the infections.

Schistosoma Sp. • It inhabits the blood vessels of large intestine of man. • The infection of blood fluke causes schistosomiasis in human beings. • Snail host is intermediate in life cycle completion. • Sexes are separate and sexual dimorphism is pronounced. • Diseases: in heavy infection cardio-pulmonary schistosomiasis, fibrosis, and loss of function in intestine, spleen, prostate and in urinary bladder have been found. • Prevention and control: Infection can be controlled by sanitary disposal of human faeces and urine. Antimony compounds are used for treatment.

Taenia solium • Known as Pork Tapeworm and found in small intestine of man. • Body is elongated, flattened, ribbon like and differentiated into scolex, neck and strobila. • Alimentary canal is absent. Life cycle involves primary and intermediate host. • Each proglottid is hermaphrodite. • Disease: Infection is followed by abdominal pain, nausea, anaemia, indigestion, diarrhoea and eosinophilia etc. • Prevention and control : The Taeniasis can be controlled by the use of quinacrine hydrochloride and atabrin. Prevention needs properly cooked pork.

Taenia saginata • It is the most common of large human tapeworm. • Prevalent in beef eaters. • Commonly called as the beef tapeworm because larva usually occur in flesh of cattle. • Adult worm lies attached in the mucosa of the intestine of man. • It is much larger the Taenia solium and may attain a length of 4 to 12 m ( even 25 m) , longer than the intestine in which it lives. • Rostellum and hooks are lacking. • It may consist of up to 2, 000 proglottids, producing from 8 to 10 proglottids daily.

• Intermediate host are cattle and buffaloes. • Disease: The infection causes a no. of disorders and diseases as in case of T. solium. The vegetarians have no chance of infection by the beef tapeworm. • Prevention and control: Beef should be taken as food after thorough cooking. • The drugs like atabrin and quinacrine hydrochloride are recommended for the control after infection.

Nematodes • • Commonly known as roundworms. Include worms parasitic on animals as well as the plants. Found in every ecological condition. Inhabit in fresh water, salt water animal and plant tissues.

Ascaris lumbricoides • It is commonly known as ‘Round worm’ and inhabits the small intestine of man and is more common in children. • Animal show sexual dimorphism. • Disease : a lumbricoides causes ascariasis which is more common in children than in adult persons. In the intestine of man these worms take the digested food materials. • Prevention and control: before eating, green vegetables should be thoroughly washed and cooked properly. • It can be treated by administering antihelmithic drugs such as oil of Chenopodium, Alcopar, Bendex and Zentel etc