parasite- worms Flashcards
What are helminths?
Helminths are parasite worms.
What can cause helminth infections?
Helminth infections can be caused by roundworms, flukes, or tapeworms.
How do helminths infect humans?
Helminths infect humans by ingesting eggs, ingesting larvae, or direct penetration of larvae through the skin.
What is worm burden?
Worm burden refers to the number of worms present in a host.
Can individuals with few adult worms be asymptomatic?
Yes, people with few adult worms may be asymptomatic.
What are nematodes?
Nematodes are a type of roundworm found worldwide, including the U.S.
female and male worms
How are nematodes transmitted to humans?
Nematodes are transmitted to humans by ingestion of eggs, penetration of skin via larvae, or through an insect vector.
How do adult worms survive in humans?
Adult worms absorb nutrients from partly digested intestinal contents or suck human blood, potentially causing nutrient deficiencies.
What is Enterobius vermicularis?
Enterobius vermicularis, or pinworm, is the most common parasite in the U.S., especially during summer months.
How is pinworm transmitted?
Pinworm is transmitted via oral-fecal route; very contagious.
specifically through pica
How is pinworm diagnosed?
Pinworm is diagnosed using a pinworm paddle, not stool culture.
What is the life cycle of Enterobius vermicularis?
The life cycle involves hatching eggs in the morning, itching, ingestion, maturation in the intestine, and laying eggs in the perianal area.
What is Trichuris trichiura?
Trichuris trichiura, or whipworm, is mainly found in dogs and is transmitted through infected warm soil.
What are the symptoms of whipworm infection?
Symptoms depend on worm burden and can include rectal prolapse if untreated.
What is Ascaris lumbricoides?
Ascaris lumbricoides is a large intestinal roundworm that can cause damage and blockage in the intestines.
What is the life cycle of Ascaris lumbricoides?
The life cycle includes swallowing eggs, hatching in the intestine, migrating to the lungs, and returning to the intestine.
What is Necator americanus?
Necator americanus, or New World hookworm, is known for its blood-sucking ability and can cause severe anemia.
How does Necator americanus infect humans?
It infects humans through the filariform stage that penetrates the skin.
goes directly to the blood vessels
also coughed up and swallowed
What is Strongyloides stercoralis?
Strongyloides stercoralis, or threadworm, is unique as it reproduces without a male worm.
What is the infective and diagnostic form of Strongyloides stercoralis?
The infective form is filariform, while the diagnostic form is rhabditiform.
What is Trichinella spiralis?
Trichinella spiralis causes trichinosis and is contracted from eating undercooked game meat.
What is Dracunculus medinensis?
Dracunculus medinensis, or guinea worm, is the largest adult nematode worm, reaching up to 3 feet long.
How do humans get infected with Dracunculus medinensis?
Humans ingest larvae by drinking water contaminated with infected water fleas- copepods!!
number of worms present are a result of how many
eggs/ larvae the human ingested
infective and diagnostic form for Enterobius Vermicularis
eggs
infective and diagnostic for trichuris trichiura
eggs
what co-infects with Trichuris trichiura
ascaris
what does egg look like for Trichuris trichiura
bipolar plugs
what technique is used for Ascaris lumbrociodes
sedimentation due to size
what do eggs look like in Ascaris lumbrociodes
mamillated/ corticated (bumpy) bile colored and thick wall
due to large size what can Ascaris lumbrociodes do
wrap around intestines, appendix and cause blockages
causes secondary infections
diagnostic and infective phase for Ascaris lumbrociodes
eggs
what is the transmission called for Ascaris lumbrociodes
liver-lung migration
diagnostic form of Necator americanus
egg
infective form of Necator americanus
filariform stage
what is Necator americanus known for
blood sucking ability and cause serve anemia
what does Necator americanus produce
cutaneous larva migrans
travels underneath the skin
what does Necator americanus mouth look like
long buccal cavity
cycle of Stronglyloides stercoralis
Feet–Travel via blood to lungs and be coughed up
what does mouth look like on Stronglyloides stercoralis
short buccal cavity
how does Stronglyloides stercoralis increase worm borden
autoreinfection
what is autoreinfection
transform from rhabditiform to filariform without ever leaving the human host
what disease is serious for immunocompromised
Stronglyloides stercoralis because will not show symptoms until become immunocompromised
smallest nematode worm
Trichinella spiralis
humans ingest meat infected with larvae in the muscle which affects
straited muscle
worm produced more larvae which infect striated muscle of human called
nurse cells
what parasite diagnosed by serology or muscle biopsies
Trichinella spiralis
cycle of Dracunculus medinensis
larve hatch into worms and move to subcutaneous tissues in extremities
-causes blisters and once ruptured, worms exit through these
DO NOT pull out worm, need pencil to wrap around
if breaks off causes secondary infections because not fully out
how can Dracunculus medinensis be decreased
filter water with piece of cotton or gauze
