Parasitology: Parasitic Worms Flashcards
A patient presents with anal pruritis.
The Scotch Tape test is positive.
Diagnosis? How is it spread?
Enterobius vermicularis (pinworm, subset of roundworm)
Fecal-oral spread.
How to treat Enterobius vermicularis (pinworm)
Bendazoles or pyrantel pamoate
(because worms are bendy)
Patient presents with intestinal discomfort.
Microscopic examination of the feces reveals eggs.
Diagnosis and spread?
Ascaris lumbricoides (giant roundworm)
Fecal-oral spread.
How would you treat Ascaris lumbricoides (giant roundworm)?
Bendazoles or pyrantel pamoate
(because worms are bendy)
A landscaper presents with vomiting, diarrhea, and epigastric pain. He says he usually works barefoot.
You’re suspicious of a parasitic disease.
Likely diagnosis and spread?
Strongyloides stercoralis, a roundworm
Larvae in soil penetrate the skin.
Treatment for Strongyloides stercoralis?
Ivermectin or albendazole.
Patient presents with fatigue and abdominal discomfort.
A CBC confirms microcytic anemia.
What are some parasitic worms that can cause these symptoms?
How are they spread?
Hookworms (a subset of roundworm):
- Ancylostoma duodenale*
- Necator americanus*
Larvae penetrate skin.
How to treat hookworm infections? (Ancylostoma duodenale, Necator americanus)
Bendazoles or pyrantel pamoate.
A patient presents with blindness and black skin nodules.
He confirms a recent black fly bite.
Diagnosis?
Onchocera volvulus, a roundworm
Causes hyperpigmented skin and river blindness (black flies, black skin nodules, “black sight”)
Allergic reaction to microfilaria possible.
Treatment for Onchocera volvulus?
Ivermectin (ivermectin for river blindness)
Patient presents complaining of seeing “something floating in his eye”.
Upon examination, you see small worms in her conjunctiva.
Diagnosis? Spread?
Loa loa, a roundworm
Either a swollen skin infection or worms in conjunctiva.
Spread by deer fly, horse fly, or mango fly.
How to treat loa loa?
Diethylcarbamazine
Patient presents with elephantitis.
You suspect a roundworm infection.
Diagnosis? Spread?
Wuchereria bancrofti
Spread by female mosquito. Can take 9 months-1 year to become symptomatic.
Treatment for Wuchereria bancrofti?
Diethylcarbamazine
A young child presents with infection of several organs with a roundworm.
Diagnosis? Spread?
Toxocara canis, a roundworm.
Disseminated infection called Visceral larva migrans
Spread by fecal-oral route.
How to treat Toxocara canis?
Albendazole or mebendazole.
What are the roundworms that cause infection when ingested?
Enterobius - Anal pruritis, Scotch Tape test
Ascaris - Intestinal infection
Toxocara - Cisceral larva migrans
“You’ll get sick of you EAT these!”
What are the nematodes/roundworms that cause infection when exposed to the skin?
Strongyloides - Vomiting, diarrhea, epigastric pain
Ancylostoma - Anemia, hookworm
Necator - Anemia, hookworm
“These get in your feet from the SANd.”
What nematodes that cause infection when spread by insect bites?
Loa loa: Worm in conjunctiva, deer, horse, and mango flies
Onchocerca: Black flies, black nodules, black sight
Wuchereria bancrofti: Female mosquito, elephantitis
“Lay LOW to avoid getting bitten”
Patient presents with intestinal discomfort.
He ate at a pig roast recently.
Most likely parasitic worm? How is it spread?
Taenia solium - a cestode/tapeworm
Causes intestinal infections when larvae cysts are eaten from uncooked pork.
Patient presents with numerous seizures.
MRI finds several brain cysts.
Possible infectious worm? Spread?
Taenia solium - a cestode/tapeworm
This syndrome is called cystericerosis (neurocystericosis when in brain)
Ingestion of eggs can result in this syndrome.
How to treat Taenia solium?
Praziquantel
Albendazole for neurocystericerosis.
A patient presents with fatigue.
A CBC shows macrocytic anemia.
He admits to loving sushi.
Possible worm infection? Route of transmission?
Diphyllobothrium latum, a cestode/tapeworm.
Ingestion of larvae from raw freshwater fish. Vitamin B12 deficiency induced from tapeworm competition in intestine.
How to treat Diphyllobothrium latum?
Praziquantel.
A dog handler presents with unrelenting abdominal pain.
An abdominal CT shows multiple cysts in the liver.
The surgeons preinject the patient with ethanol before beginning a removal procedure.
Diagnosis? What’s with the ethanol?
Echinococcus granulosus
Caused by ingestion of eggs from dog feces.
Hydatid cysts in liver - anaphylaxis can result if antigens are released (ethanol kills cysts before removal to avoid this complication).
How to treat Echinococcus granulosus?
Albendazole.
Patient presents with abdominal pain and splenomegaly.
Biopsy of the liver shows granulomas, fibrosis, and inflammation.
Possible parasitic infectious agent? Spread?
Schistosoma - a trematode (fluke)
Snails are host; cercariae penetrate skin of humans
Chronic infection can cause squamous cell carcinoma of the bladder (painless hematuria)
How to treat Schistosoma?
Praziquantel.
Patient presents with horrible RUQ pain.
He admits to enjoying undercooked fish. You diagnose cholelithiasis.
Diagnosis? Source? Important association?
Clonorchis sinensis, a trematode (fluke)
Acquired from undercooked fish.
Causes biliary tract inflammation -> pigmented gallstones
Associated with cholangiocarcinoma.
How to treat Clonorchis sinensis?
Praziquantel.
