SchistosomiasisBlood and Lymphatic

System

Schistosomiasis (bilharziasis)• Schistosomiasis transmission has

been reported from 78 countries (WHO, 2015).

• In 2013 : > 40 million people, were treated for schistosomiasis.

• at least 90% of those requiring treatment live in 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 DistributionS. 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

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

Life Cycle

Intermediate host

Source: http://www.infectionlandscapes.org/2012/06/schistosomiasis.html

Oncomelania snail

Biomphalaria snail

Bulinus snail

Transmission :

• contaminate freshwater sources with their excreta containing parasite eggs which hatch in water.

• People become infected when larval forms of the parasite (cercaria) penetrate the skin during contact with infested water.

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)• Eggs secreted by adult worm pairs enter the

circulation and lodge in organs ( >>> liver)

• immune responses to schistosome eggs commonly lodge in the liver granulomatous reactions 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

Treatment

• The goal : reduction of worm load

reduction of egg production

reduces morbidity and mortality

Treatment

• Praziquantel (drug of choice)• Dose : 40 - 60 mg/kg per day orally in 2 – 3 divided doses for one day

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