Helminths Flashcards
What would be a characteristic finding in a CBC for any worm infection? Why?
Eosinophilia
Eosinophils kill worms/parasites
If a patient has eosinophilia and infiltrates on CXR, what needs to be considered as a differential?
Pneumonic phase of a parasitic infection
How does the path to the lung differ between Necator americans (hookworm) and Ascaris lumbricoides?
Necator americans- Can penetrate foot-> lung
Ascaris lumbricoides- From intestine-> lung
Which of the roundworm infections will NOT present with eggs in a stool sample?
Strongyloides stercoralis- only larvae in stool
What organism is classically acquired from eating undercooked pork?
Trichinella spiralis
What type of worm infections do NOT have an elevated eosinophil count? Why?
Trichuris trichiura and Enterobius vermicularis (whipworm and pinworm).
Because there is no transit outside the intestine
What organism is diagnosed by the “scotch tape” test?
Enterobius vermicularis (pinworm)
What organism causes river blindness? What is the vector?
Onchocerca volvulus
Black flies
What organisms cause elephantiasis? Vector?
Wuchhereria bancrofti and Brugia malayi
Mosquito vector
What is Nocturnal periodicity? What disease has this phenomenon?
Few organisms circulate in daylight hours
Elephantiasis dx via microfilariae in blood at night
What type of worm is removed by slowly twisting it around a stick until it is out?
Dracunculus medinensis (Guinea worm)
What is the animal host of blood flukes?
Snails
What kind of helminth can lead to a Vitamin B12 deficiency?
Diphyllobothrium datum (Fish Tapeworm) absorbs B12
What tapeworm has no intermediate hosts?
Hymenolepis nana (Dwarf tapeworm)
What tapeworm infection is commonly associated with seizures in adults? How is it transmitted?
Neurocysticercosis- Taenia solium (Pork Tapeworm)
Transmitted via ingestion of larvae in undercooked pork
What organism causes fluid-filled hyatid cyst formation, especially in the liver?
Echinococcus (Extraintestinal tapeworm)
What is the main symptom of Enterobius vermicularis?
Anal pruritis (pinworm)
What worms can grow large enough to cause an intestinal obstruction?
Ascaris lumbricoides
What protozoa has characteristic football-shaped eggs?
Trichuris trichuria (whipworm)
What organism is associated with elevated creatanine kinase levels after eating undercooked pork?
Trichinella spiralis
How is Wuchereria bancrofti transmitted?
Microfilariae transmitted by female mosquito
What is the beef tapeworm called? How does it usually present?
Taenia saginata Usually asymptomatic (can have weight loss)
What is the tapeworm called that comes from raw fish? What animals does it travel through before humans?
Diphyllobothrium latum
Eggs in water are ingested by a crustacean-> ingested by freshwater fish-> ingested by human
Schistosoma in the Middle East tends to be associated with what?
Squamous cell carcinoma of the bladder
What roundworm infection is acquired from eating eggs in food?
Ascaris lumbricoides
What is the enterotest? What is it used to diagnose?
Long nylon string is swallowed and later pulled out of the mouth, may have larvae on it. For Strongyloides stercoralis dx (no eggs in stool).
What is the intermediate host of Dracunculus medinensis?
African and Asian freshwater copepods (crustaceans)
What is Katayama fever? What causes it?
Follows schistosomal infection as the adults begin to lay eggs-> fever, hives, HA, cough, weight loss.
What tapeworm are humans dead-end hosts for? What perpetuates its life cycle?
Echinococcus granulosus- Extraintestinal tapeworm
Dogs and sheep
How do the heads (scolex) of the beef and pork tapeworm differ?
Taenia solium has hooks (pork)
Taenia saginata has suckers (beef)
What organism causes hydatid cyst formation?
Echinococcus (extraintestinal tapeworm)
