Schistosomiasis

Blood and Lymphatic System

Schistosomiasis (bilharziasis)

• > 200 million people are infected worldwide (WHO, 2013)

• 243 million people required treatment for schistosomiasis in 2011.

• >200 000 deaths per year are due to schistosomiasis in sub-Saharan Africa.

Schistosomiasis (bilharziasis)

• >>> School-age children are often most at risk tend to spend time swimming or bathing in water

• >>> in tropical and sub-tropical areas; in poor communities with poor sanitation, no adequate water resources

Species Geographic Distribution

S. japonicum Southeast Asia , Japan, parts of China and Indonesia (Central of Sulawesi).

S. mansoni Africa, Nile River valley in Sudan and Egypt, South America, Caribbean

S. mekongi Cambodia and Laos

S. intercalatum Central and West Africa.

S. haematobium Africa, Middle East

Species Intermediate host

Reservoir host

S. japonicum Onchomelania Various animals, such as dogs, cats, rodents, pigs, cow, horse and goats

S. mansoni Biomphalaria baboons

S. mekongi Neotricula aperta.

dogs

S. intercalatum Bulinus

Life Cycle

Morphology• S.j. : ♀ : 26mm x 0.3 mm

♂: 12-20 mm x 0.5 mm

Source: http://neglecteddiseases.wordpress.com/schistosomiasas/

Eggs of Schistosoma

S. japonicumS.mekongi

S.mansoni

S.intercalatum

S.haematobium

http://www.dpd.cdc.gov/dpdx/HTML/Frames/morphologytables/body_morph_figure6.htm

Intermediate host

http://www.nationalstemcentre.org.uk/elibrary/

http://www.pathobio.sdu.edu.cn/parimage/dl.jpg

Pathogenesis & Clinical Symptom

1. The incubation period • usually 14-84 days;• Penetration of cercariae causes transient

dermatitis (swimmer’s itch)• Fever, chills, • urticaria, angio-neurotic edema• cough, and muscle aches

Pathogenesis & Clinical (cont’d)

2. Acute stage• Hyperemia in the wall of intestine (adult

worm arrive in the venules• Trauma with hemorrhage ( eggs escape

from the venules intestinal mucosaintestinal canal

• Diarrhea and dysentry syndrome (severe infection)

Pathogenesis & Clinical (cont’d)• immune responses to schistosome eggs

commonly lodge in the liver cirrhosis of the liver.

Pathogenesis & Clinical (cont’d)

3. Tissue proliferation &repair• The liver decreased in size : parenchyma

replaced by the scar tissue• Splenomegaly• enlarged liver, • abdominal pain,• blood in the stool

Pathogenesis & Clinical (cont’d)

• Portal hypertension• Cirrhosis ("Pipe stem Portal Fibrosis)• Ascites• Central nervous system lesions have

been reported, but are rare.

http://www.themonsterguide.com/MGWFSwimmersItch.html

Source:http://neglecteddiseases.wordpress.com/schistosomiasas/

Biopsy of liver,lung and colon

Diagnosis

• Microscopic:–Examination of stool for eggs

• Serologic testing:

for antischistosomal antibody

Epidemiology & Control• The WHO strategy on use of anthelminthic

drugs now makes it possible to control schistosomiasis in poor and marginalized community

• Mass drugs administration / regular treatment with praziquantel (twice in a year)

• Eradication of snail with molluscacide• Health education is a must

Epidemiology & control

• In 2006, the prevalence of schistosomiasis in Danau Lindu : 0.49% and 1.08% in Napu Valley (1973: 73 %)

Prevention

• Avoid swimming or wading in freshwater when you are in endemic areas

• Drink safe water.• Vigorous towel drying after an accidental,

very brief water exposure

Thank you