GI Parasites and Worms (Quiz 2) Flashcards
what is a hallmark of intestinal helminth infections
- eosinophilia
what is the motile, feeding, reproducing form of protozoa
- trophozoites
what are the thicked walled forms of protozoa that survives in the environment and are important in transmission
- cysts
what are the flagellated forms of protozoa called
- mastigotes
what is the hygiene hypothesis
- lack of exposure to infectious agents and parasites as a child may increase susceptibility to allergic diseases by suppressing development of the immune system
transmission of entamoeba histolytica
- fecal oral
host of entamoeba histolytica
- humans only
entamoeba histolytica - intestinal trophozoites cause ______-
- amebic dysentery
entamoeba histolytica can spread to
- liver, lung, brain
entamoeba histolytica - which form is infectious
which form is pathogenic
which are shed in the feces of infected individuals
- cysts
- trophs
- both
entamoeba histolytica on histopathology
- flask-shaped ulcers
giardia lamblia transmission
- fecal oral through food/water
giardia lamblia reservoirs
- animals
giardia lamblia where are the trophozoites located
do they invade
- duodenum
- don’t invade
giardia lamblia infection will cause these symptoms
- malabsoprtion
- steatorrhea
giardia lamblia - which is the infectious portion
which is the pathogenic portion
which are shed by symptomatic people
which are shed by asymptomatic people
- cysts
- trophs
- both
- cysts only
cryptosporidium transmission
- fecal/oral by contaminated food/water
cryptosporidium source
- humans
- rarely animals
cryptosporidium - trophozoites go where
do they invade?
- jejunum
- don’t invade
cryptosporidium infection symptoms
- secretory diarrhea
cryptosporidium - which portion is infectious
which portion is pathogenic
- oocysts
- trophs and sexual stages
cryptosporidium cysts are resistant to
- chlorine
cryptosporidium problematic infection for what population
- immunocompromised
cryptosporidium - detection of ______ in fecal smears is diagnostic
- acid-fast oocysts
cestodes (tapeworms) found in
you find Taenia solium in
you find Taenia saginata in
- raw or undercooked meat
- pork
- beef
cestodes (tapeworms) adult worms go where in body
- small intestine
cestodes (tapeworms) ______ shed in feces
- eggs or gravid proglottids
cestodes (tapeworms) what do we ingest
- cysts in muscle of meat
what happens when T. solium eggs are ingested via fecal-oral transmission?
what does this cause?
is this a problem with T. saginata
- larvae form cysticerci in brain, eyes, and skin
- neurocysticercosis
- no
trematodes (flukes) and schistosomiasis
_______ stage in humans
________ stages in snails
- sexual stages in humans
- asexual stages in snails
trematodes (flukes) and schistosomiasis - transmission via
by which form
- skin penetration
- by form released by snails into fresh water`
trematodes (flukes) and schistosomiasis
___________ and ________ adult worms go to the mesenteric veins in the GI tract, eggs are shed in stool
- S. mansoni and S. japonicum
trematodes (flukes) and schistosomiasis
_____________ adult worms go to the bladder, eggs are shed in urine
can lead to increase _________ and risk of ________
- S. haematobium
- increased bladder cancer
- increased risk of HIV transmission
Enterobius vermicularis is a
- pinworm
Ascaris lumbercoides is a
- large intestinal roundworm
Enterobius vermicularis
________ are ingested and adult pinworms __________ in GI tract
- eggs are ingested from feces coated soil
- adult pinworms remain in GI tract
Ascaris lumbercoides larve travel to ________ and are ______ and ________
adults live ____________
- Ascaris lumbercoides larvae travel to lungs, and are coughed up and swallowed
- adults live in the small intestine
Ascaris lumbercoides and Enterobium eggs
- smooth Enterobium eggs
- bumpy Ascaris eggs
Necator amerianus (hookworm) gets into body how
ends up where
- penetrates skin through bare feet
- ends up in small intestine
Necator amerianus (hookworm) adults attach where
causes
- attach to intestinal mucosa
- causes bleeding and anemia
Strongyloides stercoralis larvae get into body how
end up where
what’s a characteristic symptom
- penetrate skin
- end up in small intestine
- migrating rash
how can Strongyloides stercoralis reinfect the host
- reinfect without leaving the host - auto infection
what are some antiprotozoal drugs
- Nitroimidazoles
- folate synthesis inhibitors
- aminoglycosides
- Amobocidal
nitroamidazoles used to treat
- giardia
- entamoeba
- cryptosporidia
folate synthesis inhibitors (TMP-SMX) used to treat
- cyclospora
- isospora
ahminoglycosides (paromomycin) used to treat
- Entamoeba histolytica
Ameobocial (Iodoquinol) active against
- Entamoeba cysts and trophozoites
Praziquantel MOA
used to treat
- damages tegument to cause worm paralysis
- cestodes
- trematodes
Benzimidazoles MOA
used to treat
- inhibit microtubule synthesis
- cause glucose depletion
- cestodes
- nematodes
Ivermectin MOA
used to treat
- damages invertebrate nerve and muscle cells
- causes worm paralysis
- treats nematodes
what are cestodes
- tapeworms
what are trematodes
- flukes
