Name of Organism
Means of Infection
Distribution
Ancylostoma duodenale
(Hookworm)An
South American / SE Asia /
Tropics & Sub-tropics
Necator americanus
(Hookworm)
Southeast United States
Trichinella spiralis
(Pork Trichinella)
North American
Trichuris trichiura
(Whipworm)
World Wide
Enterobius vermicularis
(Pinworms)
Unites States & rest of the
world
Wuchereria bancrofti
(Filarial) (Elephantiasis)
Tropical Countries
Dirofilaria immitis
(Dog Heartworm)
South, Gulf Coast States,
Mid-West
Ascaris lumbricoides
(Intestinal Roundworm)
World Wide
Enterobius vermicularis
Eggs hatch from scratching in sleep
ingested then hatch in duodenum
mature in large intestine
feed on intestinal contents, females
migrate to surface of anus at night
to lay eggs, eggs are light and
airborne, infective in six hours.
Trichinella spiralis
Ingest infested pork
Juveniles mature in intestines
then penetrate blood vessels
Invade organs, tissues, intestinal spaces
Enter skeletal muscles & loosen striations causing
muscles to become nurse cells of the parasite
Can also invade the heart & brain
Disease is called “Trichinosis”
Wuchereria bancrofti
Mosquito takes blood meal from human,
And injects microfilariae into blood vessel, where
they grow to adulthood
Move about the body in the lymph system
Juveniles migrate to the thoracic muscles
Mosquito bites infected human and transmits
disease, repeated infections clog lymph system
and causes Elephantiasis
Ascaris lumbricoides
Up to 200,000 eggs laid per day passing out in feces
Can remain viable in soil for years
Host swallows eggs from dirty hands , eggs hatch in duodenum
juveniles burrow through intestinal wall
Carried to heart then lungs
Break through the alveoli and craw upward to the trachea
Coughed up and re-swallowed
Returns to the intestines and lives off of intestinal contents,
eggs are shed in feces.
A heavy infestation can cause peritonitis
Heavy infestations can cause worms to wriggle out of ears,
nose, anus, etc.