Parasitic Roundworms Flashcards
What is the scientific name for roundworms?
Nematodes
Do nematoads have separate sexes?
Yes
Do nematoads have complete digestive systems?
Yes
Do nematoads have segmented bodies?
No
How do you diagnose helminth infections?
Looking at the eggs in a stool sample
Which parasite have a eggs that are flat on one side?
Enterobius vermicularis
Which parasite have eggs that look like lemons with stripes on either side?
Trichuris trichiura
Which parasite has eggs that are lump/bumpy?
Ascaris lumbricoides
Which parasite has eggs that are boring?
Hook worms
True or false: most people do not die due to helminth infections
True
What are the major consequences of helminth infections?
Malnutrition/fatigue
Which populations are more likely to be infected by helminths?
Children, poor
Which part of the US usually has the most helminth infections?
Southeastern US
What are the three stages of all nematodes?
Egg, larval, adult
True or false: nematodes do not have separate sexes
False
Which is bigger usually, the female or the male nematode?
Female
Do the adult versions of nematodes replicate inside their human hosts?
No, but the do produce eggs
What will you see in a CBC of a pt with a nematode infection?
Eosinophilia
Will the number of nematodes increase in an infection?
No, unless you ingest more eggs
What is the scientific name for a pinworm?
Eterobius vermicularis
What are geohelminths?
Nematode infection that is acquired through contact with infected soil. These nematodes need to mature in soil before they are infectious
What are the four groups of geohelminths?
Ascaris and Trichuris
Strongyloides and hookworms
Which nematodes infect through the ingestion of eggs only?
Ascaris and Trichuris
What is the primary symptom of an infection with enterobius vermicularis?
Itchy butt
What is the characteristic shape of pinworms (enterobius vermicularis)?
Eggs that are flat on one side
What is the life cycle of Enterobius vermicularis?
ingestion of eggs, leading to infection. Females will lay eggs on anus.
What is the most common helminthic infection of the US?
Pinworm infx (enterobius vermicularis)
What is the route of transmission for enterobius vermicularis?
Fecal oral route
Do pinworms (enterobius vermicularis) of other animals infect man?
No
How do you diagnose enterobius vermicularis?
Scotch tape test
What is the treatment for an infection with enterobius vermicularis? Should other family members be treated?
Mebendazoe, or pyrantel pamoate
Literature is conflicting about treating family
What is the scientific name for whipworm?
Trichuris trichuria
What does Trichurius trichuira egg look like?
Lemon shaped
What is the life cycle of Trichurius trichuria?
Adults in the cecum have sex, then produce eggs that pass in stool. These eggs mature in soil, then reinfect
Where are most cases of Trichurius trichuria (whipworm) diagnosed?
Southeastern US
What is the route of transmission for trichurius trichuria?
Fecal oral
Why are most people asymptomatic with trichurius trichuria (whipworm)?
Because there is a low worm burden (one or two worms in the intestine)
What are the symptoms of a trichuria trichuris infection, if there are any? (3)
Bloody diarrhea
Frequent sools
Rectal prolapse in children
How do you diagnose Whipworm (trichurius trichuria)?
Identification of eggs in stool (lemon shaped)
What is the causative agent in ascariasis?
Ascaris lumbricoides
What is the life cycle of Ascarius lumricoides?
Geohelminth - Eggs deposited and mature in soil. Then infect circulation, lungs, back to intestines
What is the largest of the intestinal nematodes?
Ascaris lumbricoides
What do the eggs of ascaris lumbricoides eggs look like?
Lumpy bumpy eggs
Why can you get pulmomary eosinophilia with an ascaris lubricoides infection?
They travel through the circulation and into the lungs as part of their life cycle
What is the reservoir of ascaris lumbricoides?
Humans and only humans
What is the route of transmission of ascaris lumbricoidies?
Fecal-oral, but eggs need to develop in the soil before they are infectious
Which nematodes require their eggs to mature in the soil before becoming infectious?
Geohelminths (ascaris lumbricoides, hookworms, tirchuris trichuria, strongyloides)
What are the symptoms of ascariasis (infection with ascaris lubricoides)?
Usually asymptomatic, but if there are, abd pain, n/v/d
Why can a mild cough, and pneumonitis develop in ascariasis?
due to the ascaris lumbricoides travel through the circulation to the lungs
What is the scientific name for hookworms?
Necator americanus OR Ancylostoma duodenale
How do the eggs of necator americanus (hookworms) appear?
Plain, boring
What is the life cycle of hookworm?
Eggs deposited into the environment, then hatch into larvae. These can penetrate the skin
Which nematode eggs hatch in the soil, mature into larvae, and penetrate the skin of a host?
Hookworms (Nectar americanus) and strongyloides
What is the major issue that can arise with a hookworm (Necator Americanus infx)?
Anemia in pregnant women
Can dog hookworms cause human disease?
Not really, just local skin infection (cutaneous larval migrans)
Which parasitic infections travel through the circulation, through the lungs, and back into the intestines?
hookworms, Ascarius lumbrodoies, Strongyloides
Which nematode is a facultative parasite, rather than an obligate parasite?
Strongyloides stercoralis
What is the parasite responsible for Strongyloidiasis?
Strongyloides stercoralis
What disease does Strongyloides stercoralis cause?
Strongyloidiasis
What is the only parasite the poops out larvae?
Strongyloides stercoralis
How does Strongyloides stercoralis infect its host?
Penetrates the skin
What are the two parasites that infect their host through skin penetration in the soil?
Strongyloides stercoralis and Hookworms
How do you diagnose Strongyloidiasis?
Larvae in stool
What causes the hyperinfection seen in Strongyloidiasis?
Larvae in the intestines become infectious, and penetrate the intestines, going into the circurlation
What are the symptoms of Strongyloidiasis?
Usually asymptomatic, but can show up as a URI
How do you diagnose Strongyloidiasis?
Larvae in stool or sputum
