Post on 18-Nov-2014
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.
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