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Flashcards in Wk4 GI Parasites Deck (53)
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1

Three unicellular eukaryotic parasites:

Protozoans
1. Entamoeba

2. Giardia

3. Cryptosporidium

2

Life stage of nematodes, Cestodes, and trematodes in mammal host:

Juvenile and adult worms

3

Giradia mechanism:

Presence of parasite decreases absorptive surface area

diahrrea 1-2 weeks, may resolve then return

4

Form of Giardia that gets ingested:

cysts

5

Form of Giardia present in fecal matter:

Trophozoites + cysts

6

FOUL smelling diarrhea

Flatulence

Greasy stools that float

Giardia

7

Failed sanitation system (water park, drinking water)

Diarrhea 1-2 weeks --> 30 days

Cryptosporidium parvum

8

Ingestion of SMALL oocysts

disrupts epithelial microvilli --> envelopes in host cell membrane

impaired absorption, enhanced secretion

watery, frequent, NON-bloody stools

Opportunistic (HIV)

Cryptosporidium parvaum

9

Cryptosporidium form found in feces:

oocysts

10

Infectious and damage causing forms of Cryptosporidium:

Sporulated oocysts

Sporozoites

11

Bloody-MUCUSEY loose stools

can invade liver --> abcess

Dx: cysts in stool

No fever, chills, or pus

Entamoeba histolytica

--> Amebic dysentery (differentiate from Bacillary which HAS fever, chills, and pus)

12

Location for Entamoeba histolytica:

USA at risk population:

tropics --> poverty areas

homosexual males

13

Life cycle for Entomoeba histolytica on host:

ingest cysts --> trophozoites in small intestine --> migrate to colon --> cysts and trophozoites in feces

14

Disease mech for E. histolytica:

hint: "Hitsto--lytica"

tissue lysis

15

tissue abcess in upper right liver lobe

RUQ pain

fever

weight loss

Amebic hepatitis

16

TISSUE antiparasitic (completely absorbed)

free-radical forming --> DNA strand breaks

TiniDAZOLE

MetroniDAZOLE

17

Antiparasitic

intersferes with pyruvate

moderatley absorbed -- primarily luminal

less efficacy in immunocompromised with Crypto

Nitazoxanide

18

luminal antiparasitic (amebicide)

loss of visual acuity

careful with thyroid disease

Iodoquinol

19

Luminal antiparasitic

Aminoglycoside (30s subunit)

Side Fx: diarrhea

Paromomycin

20

Systemic side effects of aminoglycosides not a problem with paromomycin?

ototoxicity

nephrotoxicity

**not absorbed

21

Most common helminth (worm) infx in the US:

Enterobius vermicularis

*a round worm

22

perianal pruritis

Enterobius vermicularis

**a round worm

23

Form of E. vermicularis ingested:

pinworm eggs

**can remain viable on surfaces for 2-3 weeks

24

Life span from egg to adult Enterobius vermicularis:

1-2 months --> live for 2 months as adult

25

Where/when do Enterobius vermicularis lay their eggs?

perianal region

at night

**larva can crawl back up for retroinfection

26

Dx for Enterobius vermicularis:

Scotch tape of anal region looking for eggs in the morning

**NOT likely in stool

27

Soil transmitted round worm

9-11 mm

eggs in stool

can be in skin and lungs

blood suckers

Necator

Necator americanus/Ancylostoma duodenale

hookworms**

28

Iron deficiency anemia

Necator

OR

Trichuris trichuria

29

Recurrent raised red rash along thighs and buttocks

Autoinfection in IC pts

a few mm in size

Strongolides stercoralis

**a round worm

30

barrel shaped eggs in feces

adults 3-5 CM

finger clubbing

bloody, mucus, watery diarrhea (Fe deficiency anemia)

Trichuris trichiura

**a round worm