Parasitology Flashcards
Where do round worms multiply?
outside the host
Describe the life cycle of the pin worm
eggs are ingested
larvae hatch in the small intestine
adults mature in the cecum
eggs laid on perianal folds
How long can eggs of pinworms live in the environment?
for two weeks
How do you treat pin worm?
Mebendazole. Treat for 2 cycles, with two weeks in between
How does a pt with strongyloides present?
A patient on steroid therapy suddenly has GI sx with nausea/weight loss/abdominal sx
-symptomology similar also to asthma/pneumonia with wheezing
Most often infection is SILENT
Does strongyloids need the host to complete its life cycle?
NO. Can live on its own in the soil
What is the diagnostic form of strongyloides?
larvae in the stool
Describe how strongyloides travels through the body
1. Skin 2 veins 3. pulmonary system 4. swallowed-->GI 5. Hyperinfection--disseminated
–>The worm CAN multiply in the host!
How big are strongyloides?
Only a couple mm long
How big is ascaris?
35 cm!
Describe the life cycle of ascaris
Egg swallowed
Mate in bowel and produce eggs
Worm does NOT multiply in host. You’ve gotta eat a lot of eggs!
How does ascaris present?
Usually asymptomatic. BUT can cause bowel obstruction.
What is the diagnostic stage of ascaris?
Stool sample shows ascaris egg
How do you treat ascaris?
Treat with piperazine
What worm causes visceral larva migrans?
dog/cat ascaris
What are the symptoms of visceral larva migrans?
retinopathy–looks like a retinoblastoma. Also, fever and eosinophilia
What is your typical pt with visceral larva migrans?
A young child eating dirt
How do you diagnose visceral larva migrans?
You need a serology
How do you treat visceral larva migrans?
albendazole
Describe the life path of schistosomiasis
Reservoir in fresh water snails
- -cerceriae penetrate skin
- -Go to the portal vein
- -adults lay eggs in the venous circulation
- -Granulomas form in lung, liver, brain, bladder
What are the most worrisome sequelae of schisto?
- Squamous cell carcinoma of the bladder
2. Portal hypertension
How do you diagnose schisto?
ova and parasite screen
How do you treat schisto?
Praziquantel
What is the disease causing state of schisto?
The eggs! The adult worms don’t cause the fibrosis and granulomatous rxn
What cell is responsible for the fibrosis in schistosomiasis?
Th2 cells
