pinworm

scotch tape test

ingestion, inhalation

whipworm

football-shaped eggs

embryonated outside body for 10 days

giant roundworm

swims against peristalsis

ingestion of embryonated eggs

Necator americansus

Ancyclostoma duodenale

hookworm attach to intestine and suck blood

live 8-16 years

enters through skin

small roundworms

filariform larvae

migrate through skin hyperinfection in immunosuppressed

encysted larvae in undercooked pork

migrate to muscle and convert muscle to nurse cells

strong IgE response creates pathogenesis and kills parasite

Wuchereria bancroftii

Brugia malayi

filarial parsites via mosquitoes

live in lymphatics

cause elephantiasis, inflammation, tropical pulmonary eosinophilia

filarial nematode via black flies

river blindness

Guinea worm

live in intestine, migrate to skin, forming an ulcer

infect crustaceans, humans via water

blood flukes

snails intermediate hosts, release cercariae which penetrate human skin

TNF induces egg production

beef tapeworm produce proglottids, which release and pass through stool

scolex head attaches to intestinal wall

eggs release oncosphere, larva invades striated muscle, lives as cysticercus, develops into tapeworm

pork tapeworm

cysticercus can form in many tissues

proglottids shed

small dog tapeworm

fluid cysts

fish tapeworm

from undercooked fish with larvae

amebiasis

trophozoite stage (pathogenic)

cyst (infectious stage)

flask-shaped lesions, mitoplasts

binucleated, 4 flagella, mitoplast

sudden explosive diarrhea

water borne, wild animal carriers, campers

obligatory intracellular parasites

infectious oocysts

farm animal reservoirs

explosive, perfuse watery diarrhea

Enterocytozoon bienusi

Encephalitozoon intestinalis (microsporidosis)

obligatory intracellular protozoans

polar tubule coiled inside spore