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Schistosomiasis. Katrise Danielle Blades, MPH Walden University PH 6165-4 Dr, Raymond Thron Spring ,2009. Schistosomiasis. Overview Epidemiology Pathogenesis Diagnosis and treatment Vaccination Control Prevention. Overview. Theodor Bilharz (1851) Pirajá da Silva (1908)
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Schistosomiasis Katrise Danielle Blades, MPH Walden University PH 6165-4 Dr, Raymond Thron Spring ,2009
Schistosomiasis • Overview • Epidemiology • Pathogenesis • Diagnosis and treatment • Vaccination • Control • Prevention
Overview • Theodor Bilharz (1851) • Pirajá da Silva (1908) • 2nd most socioeconomically devastating parasitic disease. • 3 species that infect humans
Epidemiology • Origin • Africa • New World • Intermediate host • Human waste in water • Survival of these parasites depends on human habits of polluting water with their own feces.
Epidemiology • Most Vulnerable people: • Farmers • Fishermen • Children • Moslem countries • They perform ablution
Epidemiology • Factors that influence transmission • Economic level • Education level • Sex • Males have the highest rates of infection and are the most intense • Age
Epidemiology • Protective immunity to super infection is elicited • By repeated exposure to cercaria • Presence of adult worms • Resistance to re-infection • Adults (most apparent) • Children (least resistant) • During the age of 8 to 18 years of age
Pathogenesis • Is unusual • Due to eggs and not to adult worms • Has three phases • Migratory • From the time of penetration until maturity egg production • Symptom less • Acute • Chronic
Pathogenesis • Acute Phase • Katayama Fever • Schtistosome being producing eggs • Symptoms include • Chills and fever • Fatigue • Lymphadenopathy • Many eggs are carried by the hepatic portal circulation back to the liver.
Pathogenesis • Chronic Phase • Endemic areas • Asymptomatic • Intestinal • Mild, chronic, bloody diarrhea • Abdominal pain • Lethargy • Schistosomiasis haematobia • Pain on urination and blood in urine
Pathogenesis • 8% of cases of infection S. japonicum and S. mansoni development of egg granulomas and fibrosis in the liver seriously impedes portal blood flow. • Enlargement of the spleen
Pathogenesis • S. japonicumtend to involve the small intestinal • Eggs of S. japonicum reach the brain more often • Of the other 60% of all neurological diseases of Schistosomiasis all brain lesions are due to S. japonicum • S. haematobium is the least seroius • Pain is most intense at the end of urination • Strong evidence nmjmnb that it cause bladder cancer.
Diagnosis • Identification of eggs un stools or urine • Kato-Katz technique • Tissue biopsy • Antibody detection • Schistosomiasis is readily treated using a single oral dose of the drug Praziquantel annually
Control • Education • Control by Chemotherapy • Lowered from 60.3% to Helling-Giese 1996.8% one after treatment with parziquantel • Vector Control
Control • Control of snails • Environmental management measures • Stream channelization • Seepage control • Canal lining • Canal relocation with deep burial of snails, can prevent increase in transmission • Procambarus clarkii
Vaccination • Would have great potential value • Protection can be conferred by irradiated cercariae • A number of parasite-derived antigens confer partial protection against re-infection when used to immunize mice, rate, and other animals.
Prevention • Avoid Swimming • Drink Safe Water • Heat bath water for 5 minutes at 150 F • Vigorously towel down after accidental contact with water.
References • Audibert, M., R. Josseran, R. Josse, and A. Adjidji.1990. Irrigation, Schistosomiasis, and malaria in the Logone Valley, Camerron. Am. J. Trop. Hyg. 42:550-560. • Bergquist, N. 1995. Controlling schistosomiasis by vaccination: A realistic option? Parasitol. Today 11:191-193. • Bickle, Q. D., M. G. Taylor, M. J. Doenhoff, and G. S. Nelson. 1979. Immunization of • Mice with gamma-irradiated intramuscularly injected Schistosoma mansoni. Parasitology. 79:209-222. • Brand, K. G. 1979. Schistosomiasis- Cancer: Etiological consideration. Acta Tropic 36:203-214. • Capron, A. 1998. Schistosomiasis: Forty years’ war on the worm. Parasitol. Today 14:379-384. • Grassi, L., M. T. Jorda, Z. Andrade, and S. M. G. Cappa.2001. Shortreport: Schistosoma mansoni mirabilis are killed by the defense system of an Argentine Strain of Biomphalariastraminea. Am. J. Trop. Med. Hyg. 65:290- 292.
References • Gryseels, B. 1994. Human resistance to Schistosoma infections. Parasitol. Today 10:380- 384. • Hagan, P., and H. A. Wilkins. 1993. Concomitant immunity in schistosomiasis. Parasitol. Today 9:3-6. • Helling-Giese, G., E. F .Kjetland, S. G. Gundersen, G. Poggensee, J. Richter, I. Krantz, and H. Feldmeier. 1996. Schistomiasis in women: Manifestation in the upper reproductive tract. ActaTropia 62:225-238. • Hofkin, B.V., G. M. Mkoji, D. K. Koech, and E. S. Loker. 1991. Control of Schistosome-transmitting snails in Kenya by the North American crayfish Procambarusclarkii. Am. J. Trop. Med Hyg. 45:339-344. • Loker, E.S. 1983. A comparative study of the life histories of mammalian schistosomiasis. Parasitology.87:373-369.
References • Madsen, H. 1990. Biological methods for the control of freshwater snails. Parasitol. Today 6:237-Helling-Giese 19961. • Osmundsen, J.A. 1965, August 22. Science Battle is on against a dread crippler. The New York Times, p.8E. • Pointier,J.P., and J. Jourdane. 2000. Biological control of the snail hosts of schistosomiasis in areas of low transmission; The example of the Caribbean are. Acta. Tropica. 77:53-60. • Roberts, L., J. Janovy, 2005. Foundations of Parasitology. 7th Edition. McGraw-Hill. New York, NY. • Spencer, H. C., E. Ruiz-Tiben, N.S. Mansour, and B. L. Cline. 1990. Evaluation of UNICEF/Arab Republic of Egypt/WHO Schistosomiasis Control project in Beheira Governorate. Am. J. Trop. Med. Hyg. 42:441-448. • Strickland, G. T., and M. F. Abdel-Wahab.1991.Schistosomiasis. In G.T. Strickland (Ed.) Hunter’s Tropical Medicine, 7th ed. 81 Philadelphia: W. B. Saunders Co., pp.781-809.
