Term
| how do pt with giardiasis present? |
|
Definition
| abdominal distention, malabsorption, failure to thrive, watery/foul smelling/floating diarrhea, belching, weight loss |
|
|
Term
| how does giardia affect intestinal villi? |
|
Definition
| giardia causes blunting of the villi - what leads to watery diarrhea |
|
|
Term
| what is the pathogenesis of a giardia infection? |
|
Definition
| villus blunting, crypt hyperplasia, diminished brush border enzymes, and cellular infiltration |
|
|
Term
| how is giardia transmitted? |
|
Definition
| person to person, either fecal-oral/sexual contact |
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|
Term
| what are the virulence factors for giardia? |
|
Definition
| 1) suction disk (how organisms attach to mucus membrane), which diarrhea is an attempt to remove and which functions as a mechanical barrier to absorption. (giardia also competes with pancreatic lipase, which causes fat malabsorption/bile salt secretion) inhibition. 2) flagella |
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Term
| what are the metabolically active and protected forms of giardia? |
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Definition
| the trophozoites are metabolically active and can cause damage - however they are fragile and use their cyst form to resist pH changes/drying/heat/chlorination |
|
|
Term
| what does the giardia trophozoite look like? |
|
Definition
|
|
Term
| what rx will usually tx giardiasis? |
|
Definition
| metronidazole, if HIV+, use albendazole |
|
|
Term
| how do beavers play a part in giardia spread? |
|
Definition
| they act as amplifying hosts as their feces are distributed in streams |
|
|
Term
| what is the pattern of diarrhea seen in giardiasis? |
|
Definition
|
|
Term
| can giardia cause lactose intolerance? |
|
Definition
| it is very common to have lactose intolerance following giardiasis |
|
|
Term
| what are the intestinal spore forming protozoa? |
|
Definition
| cryptosporidia, cyclospora, isospora, and microspora |
|
|
Term
|
Definition
| an acid-fast staining intracellular, extracytoplasmic protozoa often found in AIDS pts (called HIV enteropathy) |
|
|
Term
| what are the 3 AIDS-defining parasites? |
|
Definition
| cryptosporidium, isospora, and toxoplasmosis |
|
|
Term
| what needs to be checked if a pt has chronic diarrhea for more than 30 days? |
|
Definition
|
|
Term
| how can cryptosporidium be transmitted? |
|
Definition
| mostly fecal-oral, sometimes sexually |
|
|
Term
| what is the tx for cryptosporidium? |
|
Definition
| nitazoxanide - which can also be used for giardia |
|
|
Term
|
Definition
| a protozoa which contaminates fruit/vegetables, which dr. bright recommends soaking in vinegar to cleanse. |
|
|
Term
| what is the difference between cryptosporidium and cyclospora? |
|
Definition
| cyclospora is bigger, variable to acid-fast staining, but will respond to florescent/saffrin staining and non AIDS-defining. cryptosporidium is uniform for staining and is AIDs-defining |
|
|
Term
| what is cyclospora treated with? |
|
Definition
|
|
Term
|
Definition
| a primitive, obligate, intracellular, spore-forming parasite with an extensive host range and capable of simultaneous or sequential infections |
|
|
Term
| how do immuno-competent pts with microsporidiosis fare? |
|
Definition
| these pts experience diarrhea, but will clear the organism |
|
|
Term
| how do AIDS pts with microsporidiosis fare? |
|
Definition
| microspora can disseminate to the brain which may be lethal |
|
|
Term
| what is used to diagnosed microsporidiasis? |
|
Definition
|
|
Term
| what virulence factor is associated with microspora? |
|
Definition
| a polar tubule, which extrudes from the spore and penetrates the plasma membrane of the host cell like a hypodermic needle - unique. |
|
|
Term
| what are the presenting features of a microspora infection which disseminates to the eyes? |
|
Definition
| this is called kerato-conjunctivitis and consists of dry eyes, FB sensation, ocular pain, blurred vision, and photophobia. *consider microspora if an infection is not clearing with anti-fungals, anti-bacterials, or anti-virals |
|
|
Term
|
Definition
| another AIDS-defining parasite, which is ellipical and large. it is also not immediately infectious (like cryptosporidium) as it takes some time outside the body to mature. |
|
|
Term
| eosinophilia 99.9% is due to a helminth infection except for when it is _______? |
|
Definition
|
|
Term
| since isospora causes eosinophilia, what may be seen in infected pts urine? |
|
Definition
| charcot-leyden crystals (rhomboid-shaped breakdown products of eosinophils) |
|
|
Term
| what is isospora belli treated with? |
|
Definition
|
|
Term
| what is entameba histolytica? |
|
Definition
| a very virulent parasite which is transmitted fecal-oral/sexually and can disseminate (some to liver, lungs). pts can present with colitis, and about 10% of the 3rd world are colonized. |
|
|
Term
| what kind of diarrhea does entameba histolytica cause? |
|
Definition
| dysentery, or bloody diarrhea (+WBCs). histolytica – “lyses” “blood cells”. this needs to be in the ddx for bloody diarrhea/systemic infection along with the bacteria: salmonella, shigella, and e. coli H157:O7. |
|
|
Term
| how is E. histolytica diagnosed? |
|
Definition
| serology/fecal antigen test from fresh stool |
|
|
Term
| how do ulcers caused by E. histolytica appear? |
|
Definition
|
|
Term
| what drugs are used to tx amoebiasis such as an E. histolytica infection? |
|
Definition
| metronidazole: for dissemination to liver/lungs and diloxanide/paromomycin/iodoquinol: to keep drug in the large intestine |
|
|
Term
| what might a pt infected with E. histolytica present with? labs? |
|
Definition
| fever, RUQ pain, hepatic tenderness, and hepatomegaly. labs: leukocytosis w/o eosinophilia, rasied ESR and alk phos |
|
|
Term
| what is the classic hepatic aspirate with amebic hepatitis? |
|
Definition
|
|
Term
|
Definition
|
|
Term
| how does cutaneous amebiasis occur? |
|
Definition
| E. histolytica can disseminate hematogenously |
|
|
Term
| what needs to be in the ddx for amoebiasis? |
|
Definition
|
|
Term
| what tx is contra indicated for amoebiasis? |
|
Definition
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