SCHISTOSOMIASIS

SCHISTOSOMIASIS(Bilharziasis/Snail Fever)

By: Nelhbenson LaurenteBSN III-A, Group 2

DefinitionThis is a slowly progressive disease

caused by blood flukes of class trematoda. It is a chronic wasting disease common

among farmers and their families in certain parts of the Philippines.

This is not only a public health concern but also a socio-economic problem because by causing ill-health, it reduces agricultural productivity (DOH, 1988).

Etiologic Agent

The cause of the disease is a parasitic worm, Schistosoma japonicum.

Incubation Period

The incubation period is at least 2 months.

Three major types of the organism

1. Schistosoma japonicumThis agent infects the intestinal

tract (Katayama Disease)It is found to be the only type that

is endemic in the Philippines.This is also known as “Oriental

schistosomiasis”

2. Schistosoma mansoniIt also affects the intestinal tractIt is common in some parts of

Africa

3. Schistosoma haematobiumIt affects the urinary tractIt can be found in some parts of

the Middle East, like Iraq and iran

Sources of Infection

1. Feces of infected persons

2. Dogs, pigs, carabaos, cows, monkeys, and wild rats have been found to be infected and therefore, they also serve as host

Mode of Transmission

1. The disease is transmitted through ingestion of contaminated water.

2. The disease is transmitted through the skin pores.

3. The disease is transmitted through an intermediary host, a tiny snail called Oncomelania Quadrasi.

Oncomelania Quadrasi

Characteristics of Oncomelania Quadrasi

1. The snail thrives best along the river banks, fresh water streams, creeks, canals, and swamps.

2. it ca be found clinging to water hyacinths, grasses, and decaying leaves, pieces of rotting woods, bamboos, and coconut husks.

3.It also loves to stay in areas with sandy-loam soil.

4.The adult snail is greenish-brown in color and is just as big as the smallest grain in palay.

Pathogenesis/PathologyLarvae (Cercaria)

Portal Vessels

Vessels in the largeIntestine or bladder

Liver’s venous portalcirculation

Skin or Mucous membrane

penetrate

They mature in 1-3 months

Excreted with theFeces

Liver

Portal circulation

Ulceration in the mucosa

Escape into the lumenOf the intestine

Female Cercaria lay eggs

Eggs

filtered

Scar formation

Fibrous Tissue

Ulceration healed

Small lesions(Granulomas)

resolved and replaced

Likewise

Patient’s belly

Portal HypertensionFluid accumulates

Interrupted blood flow

Liver enlarges

Increase Fibrosis

BulgingDEATH

Clinical Manifestations The signs and symptoms of the disease

depend on the site of infection, however, the following can be observed:

Swimmer’s itch(pathognomonic sign) Low grade fever, myalgia, & cough Abdominal discomfort due to

hepatomegally, spleenomegally, and lymphadenopathy.

Bloody-mucoid stool Icteric and jaundice Belly becomes big Weak, pale, and there is marked

muscle wasting Severe headache, dizziness,

and convulsion

Swimmer’s Itch

Bloody mucoidStool

Complications

1. Liver cirrhosis, portal hypertension

2. Cor pulmonale, pulmonary hypertension

3. Heart failure

4. Ascites

5. Hematemesis as a result from rupture of esophageal varices

6. Renal failure

Diagnosis Procedures

1. Fecalysis or direct stool exam

2. Kato Katz technique

3. Liver and rectal biopsy

4. Enzyme Link Immunusorbent Assay (ELISA)

5. Cercum Ova Precipitin Test (COPT) - confirmatory diagnostic test

Modalities of Treatment

1. Praziquantel tablet for 6 months; 1 tab BID for 3 months, then 1 tab OD for another 3 months

2. Fuadin injection given either IM or IV. The patient should consume 360 mg for the entire treatment

3. If the patinient continues to live in the endemic area, he frequently gets reinfected and has to be retreated

Prevent & Control

Basic principle: to interrupt the life cycle of the worm and protect people from infection.

1.Have a stool examination.

2.Reduce snail density by:Clearing vegetation thus exposing

the snail to sunshine.

Constructing drainage (canals)Improve farming by proper irrigation

and drainage, crop rotation and removal of weeds, thus, disturbing the living condition of the snail.

3. Diminish infection rate by:

Proper waste disposalControl to stray animalsPreventing people, especially children

from bathing in infested streams

TNX……… 0(^_^)0

Ibig sabihin.,salamat