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SCHISTOSOMA JAPONICUM
Prepared by:
MOHD KHAIRUL AMRAN BIN MOHAMMAD
KAMALRU AZMAN BIN DAUD
Bsc. In Medical Laboratory Technology
Faculty Of Health Science
University Teknology Mara (UiTM)
Introduction • Schistosoma japonicum is digenic trematode "digenic" means that its lifecycle includes two hosts : 1-Definitive host 2-Intermediate host
• Intermediate host of S. japonicum are snails of the genus Onchomelania hupensis spp.
• S. japonicum occurs in Southeast Asia and western Pacific countries (including China, the Philipines and Indonesia).
• Apart from humans S. japonicum infect a wide range of animals including cattle, dogs, pigs, and rodents.
Epidemiology
• Schistosomiasis is an important cause of disease in many parts of the world, most commonly in places with poor sanitation.
• School-age children who live in these areas are often most at risk because they tend to spend time swimming or bathing in water containing infectious cercariae.
• S. japonicum occurs in Southeast Asia and western Pacific countries (including China, the Philipines and Indonesia).
Stage of Shistosoma japonicum
i. Egg and miracidiumii. First stage (mother) sporocystiii. Second stage (daughter) sporocystiv. Cercariav. Schistosomulumvi. Adult schistosome
Morphology : egg
Characteristic
Egg
Shape Round to ovoid
Size 40~60 m × 55~80 m
Miracidium Contains one miracidium
Spine Present, small and lateral and often unrecognizable.Inconspicuous
Operculum Present but lack
Cercaria is infective stage
Has a body and a forked tail and has 5 pairs of penetrating glands in the body
Emerges from daughter sporocysts
Escapes from the snail
Infects man by skin penetration
Cercaria
Morphology of adult worm
Male Female
Shape Elongated cylindrical with shorter and thicker & sickle-like
Longer and slender than the male
Size 10-20 x 0.5-0.55mm 12-26x 0.1-0.3mm
Color Gray white The female is much dark.
Organ Oral sucker at top near by ventral sucker.
Has a longitudinal groove-gyncophoral canal in which the female normally resides.
Seven testes are situated one by one, each has a delicate defferens which combine to form the vas deferens and dilate to become a seminal vesical opening in the genital pore just behind ventral sucker
The vitellaria are located in the posterior part of the body surrounding the cecum.
The ovary lies in the mid-portion of the body.
The uterus lies in the anterior portion of the body filled with 50-300 eggs arranged in a single row, arising from ootype to genital pore behind the ventral sucker.
Oral sucker
Esophagus
ventral sucker
Genital pore
Testes
cecum
uterus
Mehlis gland
Ootype
Ovary
Oviduct
Vitelline duct
Intestine
Vitellaria
Gynecophoral canal
Male adult
Female adult Female adult
Different characteristics of Schistosomes
Diagram of the Life Cycle of Schistosoma japonicum
adult (♂ & ♀) in the portal vein system
Eggs passed in feces into
water via intestinal
ulsers
Miracidium hatches from egg swims actively
to penetrate intermediate host (Oncomelania
sneil)
Forming mother sporocysts then produced daughter sporocysts in
snail tissue
Daughter sporocysts
forming cercariae
and escapes
from snail into water
Shistosomolum migrate into portal circulation and mature in the mesenteric veins forming adult Schistosoma japonicum
Cercariae penetrate human skin and leave its tail, forming shistosomolum and first enters the systemic circulation
Pathogenesis• The adult worms do not multiply.• The egg is the main cause of pathology in
schistosomiasis.• The eggs penetrate the blood vessel by secreting
proteolytic enzymes.• Many eggs are stranded in the tissues or are
carried by the blood stream to other organs of the body.
• Location of S. japonicum in the mesenteric veins.• S. japonicum, present mainly in the superior
masenteric vein and its branches.• Pathology produced by S. japonicumis is greater• Some eggs find their way into the lumen of the
bowel and appear in the faeces.
Due to the cercaria and schistosomulum ( adolescent ):
1.The cercarial dermatitis appears.2.Petechiae and rashes ensue. 3.The migration of the adolescents may induce localized
pneumonitis and urticaria.
Due to adults:1.The mechanical effect and toxic effect of adults and
their metabolites cause mesenteric phlebitis, hepatitis, and abdominal pain.
2. The immune complex may cause the damage to the kidney, schistosome nephritis results from type III allergy, the esinophile increase in peripheral blood.
Pathology
Due to eggs:
The most serious damage is done by eggs. 1. Liver cirrhosis (pipestem fibrosis) 2. Splenomegaly3. Ascites 4. Granuloma 5. Ulceration
Clinical manifestations a) Initial phase: i. Fever, ii.Dry cough (pneumonitis), .iii.Urticaria
b) Acute stage: i. Chill and malaise.ii.Dysentery, blood in stool, pus and mucus.
c) Chronic stage: i. Fatigue sand strength deteriorate.ii.Loss of weight and interest.iii.Retardation of both physical and mental growth in
children.iv.Spleen and liver enlargement, anemia, v.In women menopause, sterility and abortion may
occur. vi.This stage may last from several years to 20 years.
d) Terminal stage:
i. Portal vein hypertension syndrome,
ii.Abdomen distention looks like a big drum,
iii.Emaciation looks like a fire wood Ascites,
iv.Varicosity, splenomegaly and anemia.
v.The patients die of secondary infection, upper
digestive tract bleeding, hepatic coma.
e) Ectopic lesion:
i. The damage to the central nervous system
(brain, spinal) may cause paralysis (monoplegia,
hemiplegia ).
Lab diagnosis The symptoms, signs and history of living in
endemic areas only give a presumptive diagnosis. The definitive diagnosis depends on the pathogen examination.
1. Stool examination: - Direct fecal smear for acute stage - Concentration method:
Water sedimentation method and miracidia hatching test can be done at same time.
2. Biopsy can be done by proctoscope for terminal stage.
3. Immunological tests are subsidiary for reference only.
Prevention:• Control of the source of infection: Treat the patients and domestic animal at the
same time.• Cut off the route of transmission: Snail control & Sanitary disposal of human
excreta• Protect of susceptive people: Avoid the contact with schistosome-infected water
Treatment:1.Praziquantel is most active against adult worms administered orally form in one or two doses
from 40–60 mg/kg body weight.2.Artemether is prevents the development of adult
worms