GI Parasites - Zimmer Flashcards
After a trip into the mountains, your friend Hubert is beginning to worry you. He stinks up the bathroom every time and seems extremely gassy all the time. He says he’s had diarrhea for about a week now.
What is your diagnosis?
Probably giardia lamblia
especially if he drank some unfiltered water
After a pool party at the Edgewater. 5 elementary school kids have had watery non-bloody diarrhea for about a week and a half. Oocytes have been identified in their feces.
What is the infection?
Is it possible for them to pass the infection to their families?
How would you treat it doc?
Sounds like Cryptosporidium Parvum
Yes, because it takes a very small load for infection, person to person transmission is common.
Especially affects immune compromised, AIDS
Tx with Nitazoxanide
After living for a year as a missionary in Mexico, Jim returns home because of illness. He tells you that he has been having bloody, mucus-ey loose stools. These symptoms progressed very gradually.
He is growing more worried because he now has right upper quadrant pain and a fever.
You see some suspicious cysts in his feces. What are you worried about?
It could be Entamoeba Histolytica
It may now have progressed to amebic hepatitis
(Histo-lytica = tissue lysis… get it?!)
After confirming a case of Entamoeba Histolytica dysentery, how do you treat it?
Tissue: Metronidazole or Tinidazole.
Luminal: Iodoquinol or Paromomycin
How do metronidazole and tinidazole work?
Important toxicity?
Drug breaks down forming free radicals
Free radicals cause DNA strand breakage
Tox: Don’t drink alcohol –> disulfuram-type reaction
After beginning a medication for amebic dysentery, your patient complain that it is more difficult to spot wildlife when he is out hunting. He is worried about his eyesight. What might be the problem?
If he is on Iodoquinol, a side effect is loss of visual acuity
What are the symptoms of schistosomiasis causes by?
Immune response to egg stage of schisto
They can be lodged in the intestine or bladder, this causes inflammation and scarring
(Damage to liver, intestine, spleen, lungs, and bladder over time)
Which luminal anti-parasitic targets the 30S ribosomal subunit?
Paromomycin
How does TMP-SMX work?
When is it contraindicated?
Dihydrofolate Reductase Inhibitor
Don’t use n pregnant women
A 12 year old girl is brought into clinic with a pruritic rash on her feet after visiting family for the summer in Louisiana. Gradually she has gotten more lethargic. and her mother says she seems paler then when she left. She has had some diarrhea and also a mild cough.
You run a stool sample. What do you expect to find?
Perhaps: hookwork infection!Nector more likely than strongolides
Necator Americanus eggs could be found
or strongolides larvae (SIMILAR LIFE CYCLE)
Larvae in soil penatrate the skin, enter the circulatory system, enter the lungs, are coughed and swallowed into the GI system.
One of the big give-aways was the anemia the girl experienced, hookworms like Necator are BLOODSUCKERS
You have a son in daycare. You pick him up after work and notice he is scratching his backside a lot. Like more than usual…
He also doesn’t seem to be feeling real well. He isn’t hungry and seems more irritable than usual.
What is the infection and how was he infected?
Enterobius Vermicularis (roundworm)
Eggs are laid at night in the perianal region, they can then be spread to different surfaces where they can remain viable to 2-3 weeks
REMEMBER: Eggs will NOT be found in stool. (use scotch tape)
A recent immigrant to your town comes to you worried about an infection that has gottne progressively worse.
This 43yo male has bloody diarrhea with mucus, that is often painful. HE has been having problems at work because he feels tired all the time. You are surprised (or not?) to notice that he has finger clubbing on both hands.
You send his stool to the lab and they describe barrel-shaped eggs seen microscopically.
What does he have?
How do you treat it?
Trichuris Trichiura
Tx with mebendazole
or possibly albendazole
What is the name of the parasite that just looks like actual huge worms inside you?
You can diagnose by finding eggs with very thick shells.
Usually asymptomatic or just have abdominal discomfort
Ascaris Lumbricoides
Mechanism of Albendazole and Mebendazole?
Bind parasitic beta-tubulin to inhibit microtubule formation
What kind of parasites can be killed with Pyrantel Pamoate and Levamisole?
Pyrantel for round worms (except whipworm- like trichurus)
Levamisole for roundworms
