Nemathelminthes Flashcards
Location of Enterobius vermicularis
intestinal/anal, adults in colon
Location of Trichuris trichiuria
intestine/colon, adults attach to colonic mucosa
Location of Ascaris lumbricoides
intestinal, soil
Adults free in upper intestine
Location of Necator americanus
intestinal soil
Location of Strongyloides stercoralis
intestinal soil
Location of Trichinella spiralis
muscle
Location of Toxocara canis
blood/tissue
Transmission of Enterobius vermicularis
direct egg fecal/oral
ingestion of eggs (direct person to person)
Transmission of Trichuris trichiuria
soil egg fecal/oral
ingestion of embryonated eggs
no drect person to person
Transmission of Ascaris lumbricoides
egg facal/oral
Ingestion of eggs from soil, no direct person to person
Transmission of Necator americanus
larva invades skin
Transmission of Strongyloides stercoralis
larva invades skins or autoinfective larvae
Transmission of Trichinella spiralis
undercooked pork
Transmission of Toxocara canis
soil egg fecal/oral
Definitive host of Enterobius vermicularis
Humans, no intermediate host needed
Epidemiology of Enterobius vermicularis
>200 million worldwise with >20 million in US
More prevalent in children, daycare centers, etc.
Pinworm, species name
Enterobius vermicularis
Pathology of Enterobius vermicularis (pinworm)
Itchy anus
Secondary infections from scratching
Rare bacterial infection in females due to urogential invasion
Psychological trauma
Immunity of Enterobius vermicularis
None (reinfection is possible and common)
Diagnosis of pinworm (Enterobius vermicularis)
Persistent perianal itch, restlessness, insomia
Confirm by observation of eggs (scotch tape test)
Whipworm, species name
Trichuris trichiura
Definitive host of Trichuris trichiura (whipworm)
Humans only
Epidemiology of Trichuris trichiura (whipworm)
Up to 800,000 people infected worldwise
Tropical countries, poorer communities in South US
Poor public hygiene, use of human waste as fertilizer
Diagnosis of whipworm (Trichuris trichuria)
Only by eggs in stool
Definitive host of Ascaris lumbricoides
Humans
Epidemiology of Ascaris lumbricoides
Up to 25% of people worldwide
Tropical and subtropical
Up to 4 million in the US, Appalachia, and south
Considered a US Neglected Disease of Poverty
Poor public hygiene, use of human waste as fertilizer
Which of the worms enter the venous circulation to the lungs and are coughed up & swallowed?
Ascaris lumbricoides
Hookworm (Necator amercanus)
Strongyloides stercoralis
Which worms, when stressed, can migrated to the nose, ear & peritoneal thru body wall?
Ascaris lumbricoides
What is pruitus?
From hookworms
itch is defined as an unpleasant sensation of the skin that provokes the urge to scratch
Which of the worms larva stage in the lungs can cause bronchitis?
Hookworm (Necator americanus)
Which worm causes anemia?
Hookworm (Necator americanus)
Larvae in the feces
Strongyloides stercoralis
Rash on buttocks, legs and lower back due to autoinfection
Strongyloides stercoralis
