Phylum: Platyhelminthes class: Trematoda Schistosoma President’s Office Phylum: Platyhelminthes class: Trematoda Schistosoma

Trematodes Schistosomes: Blood flukes Family: Schistosomatidae Genus: Schistosoma Spp. : Schistosoma haematobium, Schistosoma mansoni, Schistosoma japonicum. For animals (ruminant & horses) : Sch. bovis, sch. Mattheei, sch. Spindale, sch. nasalis, Sch. margrebowiei Disease : Bilharziasis or Schistosomiasis

Sch. japonicum Sch.mansoni Sch. haematobium Spp. Oriental bilharziasis Katayama disease(fever) Intestinal bilharziasis (schistosomiasis dysentery) Urinary bilharziasis (Vesical schistosomiasis), endemic haematuria Name of disease Human&domestic animals&wild rodent Human& monkeys& rodents human Final host Lung fibrosis, spleenomegally Liver fibrosis , bloody diarrhea Hyperplasia & calcification of bladder Clinical signs

Male adult worm : S. haematobium S. mansoni S. japonicum Length 10 – 15 mm 6 – 10 mm 12 – 20 mm Integument finely tuberculated coarsely tuberculated smooth No of testes 3 – 5 ( 4 ) 6 – 9 ( 7 ) in (cluster) 7 – 9 ( 7 ) (in column) Ceca reunite late reunite early reunite very late Female adult worm : Length 15 – 20 mm 10 – 14 mm 15 – 30 mm Position of the ovary posterior half anterior half middle Length of the uterus long short long No. of ova in the uterus 20 – 50 1 – 4 50 – 300 Ova : Spine terminal spine lateral spine short lateral spine (rudimntary) Present in urine, less, frequenitly in stool in stool rarely in urine in stool Habitat in human : Body vesical plexus of urinary bladder inferior mesentric vein, superior mesentric vein, less less frequently superior frequently interior Snails : (intermediate host) Bulinus truncatus Biomphalaria spp. Oncomelani spp.

Differential Features of Shistosoma spp.

Schistosoma japonicum Egg Schistosoma mansoni Egg ( in stool ) Schistosoma haematobium Egg ( in urine ) Schistosoma mansoni Egg ( in stool )

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Schistosoma spp- Cercaria Schistosoma spp- Miracidium

Oncomelania Biomphalaria

Pathogenesis It belong to a kind of allergic reaction(rapid & delayed) Formation of granuloma produced by eggs Concomitant immunity Ectopic lesion (lung & brain) "swimmer's itch", due to irritation at the point of entrance. The rash that may develop can mimic scabies and other types of rashes. Other symptoms can occur 2-10 weeks later and can include fever, aching, cough, diarrhea, or gland enlargement. These symptoms can also be related to avian schistosomiasis, which does not cause any further symptoms in humans.

Pathology Schistosome eggs, which may become lodged within the hosts tissues, are the major cause of pathology in schistosomiasis. Some of the deposited eggs reach the outside environment by passing through the wall of the intestine; the rest are swept into the circulation and are filtered out in the periportal tracts of the liver, resulting in periportal fibrosis. Onset of egg laying in humans is sometimes associated with an onset of fever (Katayama fever). This "acute schistosomiasis" is not, however, as important as the chronic forms of the disease. For S. mansoni and S. japonicum, these are "intestinal" and "hepatic schistosomiasis", associated with formation of granulomas around trapped eggs lodged in the intestinal wall or in the liver, respectively. The hepatic form of the disease is the most important, granulomas here giving rise to fibrosis of the liver and hepatosplenomegaly in severe cases. Symptoms and signs depend on the number and location of eggs trapped in the tissues. Initially, the inflammatory reaction is readily reversible. In the latter stages of the disease, the pathology is associated with collagen deposition and fibrosis, resulting in organ damage that may be only partially reversible.

Pathology In S. japonicum about two-thirds of eggs are not excreted, instead they build up in the gut. Chronic infection can lead to characteristic Symmer's fibrosis (also known as "clay pipe stem" fibroses, these occur due to intrahepatic portal vein calcification which assume the shape of a clay pipe in cross section). S. japonicum is the most pathogenic of the schistosoma species because it produces up to 3,000 eggs per day, ten times greater than that of S. mansoni. 5/11/2018

Clinical Manifestations the migratory phase lasting from penetration to maturity, (2) the acute phase which occurs when the schistosomes begin producing eggs, (3) the chronic phase which occurs mainly in endemic areas

Acute Schistosomiasis Clinical manifestations come out after 4 to 8 weeks of infection, similar to the time from egg to adult worm (40 days) Fever: intermittent, maintain weeks to months Allergic reaction: urticaria, angioneuroedema, enlargement of lymph nodes and eosinophilia Digestive syndromes: abdominal pain, diarrhea with pus and blood, constipation or diarrhea Hepatosplenomegaly.

Chronic Schistosomiasis Asymptomatic: most person are asymptomatic Symptomatic: the most common syndrome is abdominal pain with intermittent diarrhea. hepatosplenomegaly

Terminal stage of schistosomiasis Liver cirrhosis is the prominent syndrome of this stage According to the manifestations , it can be divided into types: The type of giant spleen The type of ascites

Diagnosis Epidemiologic date: occupation, history of travel to endemic area, contact with infected water Clinical date: Acute stage; chronic stage; terminal stage Laboratory findings: Blood Rt; characteristic eggs in feces; biopsy; positive immunological test

Treatment Praziquantel is the best choice of drug for the therapy of schistosomiasis Dose: chronic schistosomiasis 10mg/kg, tid. for 2 days, total 60mg/kg Acute schistosomiasis 10mg/kg,tid. for 4 days, total 120mg/kg