3. Schistosoma mansoni
Also known as Manson’s blood fluke.
In 1902 Manson discovered eggs with lateral spines.
Sambon (1907) created a new spp. and named it as S.mansonii (
produce lateral spined eggs)
Causes Intestinal Schistosomiasis
DISTRIBUTION
Widely distributed in Africa, South America and Caribbean islands.
4. HABITAT
• Adult worms reside in inferior mesenteric vein.
MORPHOLOGY
• It resembles S.haematobium except
1. Eggs have characteristic lateral spines.
2. Adult worms are smaller and their integuments are
studded with coarse tubercles
6. LIFE CYCLE
Definitive host: Humans
sometimes monkeys, dogs.
Intermediate host: Fresh water
snails of Biomphalaria.
Infectious form is fork tailed
cercaria.
MAN
MAN
SNAIL
Egg-
Miracidium
Cercaria
7.
8. CLINICAL MANIFESTATIONS
ACUTE SCHISTOSOMIASIS
1. Cercarial dermatitis ( also called Swimmer’s itch)
Pruritic rash is common manifestation
2. Katayama fever
Fever, weakness, right upper quadrant pain , arthralgia are
common symptoms
10. CHRONIC SCHISTOSOMIASIS:
1. GI Schistosomiasis:
• Abdominal pain and mucosal diarrhea and blood in stool is
common symptom.
• Periportal fibrosis is common symptom which progresses to
portal HTN, and GI hemorrhage.
2. Hepatosplenic Schistosomiasis
• This condition manifests as peripheral fibrosis, ascites ,
splenomegaly.
• Also associated with follicular lymphoma of spleen
11. DIAGNOSIS
Stool microscopy for eggs with lateral spine
Serological diagnosis by detecting Schistosomal antigen and
antibodies by ELISA, Latex agglutination, CIEP,RIA.
Ultrasonography is sensitive method for detecting periportal fibrosis,
splenomegaly
Treatment: Praziquantel – Single oral dose of 40mg/kg body weight.
Oxamniquine (15mg/kg body wt)
12. Schistosoma japonicum
Schistosoma japonicum causes oriental schistosomiasis in
human
Most pathogenic Schistosoma spp.
This condition was first described by physician Fujii and their
eggs were demonstrated by Fujinami.
DISTRIBUTION
Found in far East, Japan , China ,Taiwan
13. HABITAT
• Adult worms are in superior mesenteric vein.
• Also seen in hemorrhoidal plexus.
MORPHOLOGY
• The eggs are relatively smaller and more spherical
and has no lateral spine but shows rudimentary
lateral knob.
• About 3500 eggs may be passed daily by a single
worm
16. LIFE CYCLE
Definitive host: Humans domestic
animals like dogs.
Intermediate host: Fresh water snails of
Oncomelania.
Infectious form is fork tailed cercaria.
17.
18. CLINICAL MANIFESTATIONS
ACUTE SCHISTOSOMIASIS
1. Cercarial dermatitis
2. Katayama fever
Fever, weakness, chills, eosinophilia , cough are common symptoms
Because of higher egg output clinical manifestations are more
severe
19. CHRONIC SCHISTOSOMIASIS:
1. GI Schistosomiasis:
• Development of liver fibrosis/ Symmers’ clay pipestem
fibrosis , cor pulmonale are important complications.
1. CNS Schistosomiasis
• Headache, seizures, parasthesia are common symptoms.
22. DIAGNOSIS
Stool microscopy for typical eggs.
Serological diagnosis by detecting schistosomal antigen and
antibodies.
Ultrasonography is also done.
Treatment: Praziquantel
23. Prevention & Control
Eradication of intermediate molluscan host (snail)
Prevention of environmental pollution by faeces
Effective treatment of infected persons
Avoid bathing, swimming, washing in infected water