Wuchereria bancrofti and elephantiasis.pptx

wuchereri bancrofti is discussed

1.                                                                           pravesh       M. s c .   I Year Zoology Wuchereria bancrofti ‘The Filarial Worm’ 

2. Classification

3. Geographical Distribution             

4. Habits and Habitat                          Filarial worm is a dreaded human parasite of human blood and lymph. It is a digenetic parasite completing its lifecycle into two hosts. Final host is man harbouring the adult worms, while intermediate host is a blood sucking insect, usually a mosquito. Adult worms live coiled up in the lymph glands and lymph passage of man, where they often obstruct the flow of lymph.

5.                                    ADULT WORM Adult worms are filiform and cylindrical in shape and both body ends terminate bluntly. They are whitish, translucent, thread like worm with smooth cuticle. FEMALE WORM  Larger Measures 65 to 100 mm in length and 0.25 mm in diameter. Posterior end is straight. MALE WORM Smalle 25 to 40 mm in lenghth  and 0.1 mm in thickness. Posterisr end curved vertically. Morphology 

6. Female worm is viviparous  Gives birth to larva Called microfilariae  Is 250-300 micrometer in length and 6-10 micrometer in thickness.

7. Life Cycle                           W. bancrofti passes its life cycle in two hosts ; Man – Definitive host  Mosquito – intermediate host Eg ; Culex  Aedes  Anopheles

8. Infective form -; Actively motile third stage filariform larva infective to man.  MODE OF TRANSMISSION-; By bite of mosquito carrying filariform larva . Development in mosquito  Vector mosquito  Feeds on carrier  Microfilariae taken in blood meal  Reach the stomach of mosquito within 2-6 hr   Caste off the sheath --- Exsheathing Migrate to the thoracic muscle develop to  1st stage larva  In a week moults once or twice  2nd stage larva  In a week  3rd stage larva   Enter proboscis sheath of mosquito 

9. EXTRINSIC INCUBATION PERIOD

10. Filariasis or Elephantiasis      Filarial worms ( Wuchereria bancofti ) live in the lymphatic system of man ,where they obstruct the flow of lymph causing a serious condition known as elephantiasis in which the limbs or other body parts grow to enormous size .

11. DIAGNOSIS                     

12. PATHOGENESIS               Light infection produces no serious symptoms. It causes filarial fever, mental depression, headache, etc., In heavy infection, accumulation of living or dead worms eventually blocks the lymphatic vessesls and glands, resulting in various pathological conditions. Most  spectular is the immense swelling of the affected body parts, termed elephantiasis or filariasis. Due to lymphatic obstruction lymph cannot get back into circulatory system, accumulates into organs and causes them to swell or enlarge to fantastic proportions (lymphedema). Generally lower limbs, scotum in male, legs and mammary glands are affected. Concurrently there occurs inflammations of lymphatic vessels (lymphangitis) and lymphatic glands ( lymmphadentis ). In severe cases, abnormal connective tissue form in the affected areas to  further complicate the condition.

13. THERAPY AND CONTROL          No proper or satisfactory treatment is yet known .Infection may be reduced or eliminated.  Infection may be reduced or eliminated by eradication of microfilariae from  circulation by administering  heterazan and compounds of antimony and arsenic. An important preventive measure is protection from mosquitoes bites.

14. THANK YOU