Parasitology

Question 1

What are the three most prevalent protozoan GI parasites?

Answer 1

Giardia
Cryptosporidium
Entamoeba

Question 2

How long does diarrhea usually last with a parasitic infection?

Answer 2

Longer than one week

Question 3

What is the onset for parasitic GI infection like?

Answer 3

Gradual

Question 4

What are defined as flagellated single celled organisms?

Answer 4

Protozoans

Question 5

How are protozoans transmitted?

Answer 5

Waterborne
Oral/anal sex
Contaminated food

Question 6

What stage in the parasitic life cycle are ingested in order to initiate infection?

Answer 6

Cysts or oocysts

Question 7

How long do symptoms last for giardia?

Answer 7

1-2 weeks or more

Question 8

What is the mechanism for giardia?

Answer 8

Loss of absorptive surface area

Question 9

What is the life cycle stage of Giardia that attaches to the gut?

Answer 9

Trophozoites

Question 10

What do you see in the stool sample of someone with Giardia?

Answer 10

Trophozoites and cysts

Question 11

What are symptoms for giardia infection?

Answer 11

FOUL smelling diarrhea
Flatulence
Greasy, floating stools

Question 12

What parasitic infection is often seen where sanitation systems fail?

Answer 12

Cryptosporidium parvum

Question 13

What is the mechanism for cryptosporidium diarrhea?

Answer 13

Absorption impaired and secretion enhanced

Question 14

Who is at risk for dying from a crypto infection?

Answer 14

Immunocompromised

Question 15

What does a crypto infection look like?

Answer 15

Watery, non-bloody stool

Fever sometimes

Question 16

How do cryptosporidium attach to epithelial cells?

Answer 16

Disrupt epithelial microvilli, enveloping into the host membrane

Question 17

What do you see in the feces for cryptosporidium?

Answer 17

Acid-fast Oocysts (VERY small)

Question 18

What relative of crypto is important for outbreaks in the US?

Answer 18

Cyclospora cayetanensis

Question 19

Where is entamoeba more common to infect?

Answer 19

Tropical/subtropical climates

Question 20

Does everyone who is infected with entamoeba get ill?

Answer 20

NO! Only 10-20%

Question 21

What does entamoeba infection look like?

Answer 21

Bloody, mucousal stool

Mild symptms, but can get abscess in liver

Question 22

How is entamoeba diagnosed?

Answer 22

Cysts in the stool sample

Question 23

How does amebic hepatitis present?

Answer 23

RUQ pain
Fever
Cachexia

Question 24

What do you often see entamoeba eating on a H&E stain?

Answer 24

Red blood cells