Echinococcus sp & Mesocestoides sp Flashcards
E. granulosus
10 genotypes w variation in host association, phenotypic presentation & pathogenicity
unilocular hydatid cyst
domestic and wild canidae DH
sheep, cattle, horses IH
E. multilocularis
circumpolar distribution
multilocular hydatid cyst in IH
-resembles fluid filled grapes
domestic and wild canidae DH
rodents IH
echinococcus sp
zoonotic, humans accidental IH
adult worms in small intestine of DH
tiny worms w/ scolex, neck, immature proglottid, mature proglottid and gravid proglottid
Taenia-type egg passed in feces, morphologically indistinguishable
-eaten by mammal, obligate IH
uniocular hydatid cyst
pressure atrophy
anaphylaxis from cyst rupture
how do humans become infected?
unknowingly ingesting tapeworm eggs from various sources contaminated w dog feces
dogs roll in feces of wild canids and transport infective eggs on fur
pulmonary hydatid disease
zoonotically acquired
tapeworm associated w wild and domestic canines
humans infected by ingestion of eggs passed in feces
hydatid cysts form in liver and lungs
symptoms: cough, chest pain
rupture into pleural cavity associated w pneumothorax or pleural effusion
treatment/ prevetnion
monthly deworming for pets in areas known to be endemic
limit access to IH
treat dogs and cats before transport to non-endemic areas
mesocestoides sp
scolex w unarmed rostellum & 4 muscular suckers
segmented body
proglottids w central genital pore
distinctive eggs
obligate indirect life cycle
-eggs ingested by arthropod
-tetrathyridium develops in 2nd intermediate host
–dogs & cats DH to maintain parasite in environment
zoonotic if humans ingest tetrathyridium
clinical signs mesocestoides sp
ascites
dysorexia/ weight loss
vomiting / diarrhea
tachypena
disease results form asexual replication of worms in host and invasion of peritoneum
mesocestoides sp treatment
agressive chemotherapy w FBZ
surgical removal or worms
cleanse peritoneum w lavage
