morphology and geographical distribution of the worm as well as epidemology, its lifecycle , its definitive and intermediate host,various life stages egg, cercarie ,adult worm, the disease schistosomiasis, its symptoms and control medication,diagnostic stages,management, bilharziasis

1. NAME -PRIYAM NATH
3rd SEMESTER
017
SCHISTOSOMA
-an insight

2. INTRODUCTION
 Schistosoma is the only trematode that invades through the skin.
 Five species of schistomes infect humans
 Schistosome haematobium causes urinary tract disease the other species
causes intestinal disease
 GEOGRAPHIC DISTRIBUTION
 Schistosoma haematobium-Africa, some in Middle East, Turkey, and India
 Schistosoma mansoni-Africa and America
 Schistosoma japonicum-Far east Asia, Some parts of Africa
 Schistosoma mekongi- Southeast Asia
 Schistosoma intercalatum- central and west Africa

3. EPIDEMIOLOGY AND MORPHOLOGY
 Approximately 250 million people are infected with schistosomes and
600 million people are at risk
 Adult worms are 10 to 20mm long
 Schistosomes have separate sexes
 The male has a canal in which the slender female worm resides

4. THE EGG
 Eggs penetrate the intestinal or bladder mucosa and are passed in
stool or urine
 Other eggs remain within the host organ or are transported through the
portal system to the liver
 Excreted eggs hatch in freshwater, releasing miracidia, the first larval
stage
 Miracidia enters snails

5. THE CERCARIE
 Infective stage
 Cercarie penetrate human skin within a few minutes after exposure
 When they penetrate they lose their forked tail and transform into schistosomula
 Schistosomula mature and reach mesentric veins(S.mansonii, S.japonicum. )
,bladder vessels (S.haematobium)where they live and ovulate for duration of
hosts life

6. ADULT WORM
Schistosoma mansoni Schistosoma japonicum

7. INTERMEDIATE HOST
 Schistosoma haematobolium-
Bulinus truncatus
 Schistosoma mansoni-
Biomphalaria alexandria
 Schistosomia japonicum-
Oncomelania sp.
 Schistosomia mekongi-
Neotricula aperta

8. LIFE CYCLE

9. SCHISTOSOMA COUPLE
Schistosoma japonicumSchistosoma mansoni

10. PERIOD OF COMMUNICABILITY
 Life span-5to 10 years, so infected human can excrete eggs up to 10 years
 An infected snail can release cercarie from several weeks to 3 months of its life
 An infected snail can lay eggs 300-3000/day

11. SCHISTOSOMIASIS
 SCHISTOSOMIASIS OR BILHARZIA
 Disease affecting many people in developing countries.
 ‘Acute schistosomiasis'- snail fever and cutaneous schistosomiasis
 Low mortality rate, schistosomiasis can also be very debilitating
 Bilharzia or bilharziosis, named after Theodor Bilharz, who first described the
cause of urinary schistosomiasis in 1851.

12. SYMPTOMS
 Hepatosplenomegaly
 Muscle atrophy
 Anaemia
 Diarrhea
 Haemorrhage from the gastrointestinal tract

13. DIAGNOSTIC STAGE
 Schistosoma haematobolium
 Eggs found in urine of urinary Schistosomiasis patients
 Oval egg with terminal spine
 Schistosoma mansoni
 Eggs found in stool of intestinal Schistosomiasis patients
 Oval egg with lateral spine

14. MANAGEMENT
 Contaminated water should be avoided
 Sanitary disposal of sewage
 Prevent contamination of water by feces and urine
 Destruction of snails
 Treat the patients
 No vaccine is available
 Praziquantel is effective against all species

15. Thank youThank u…