Protozoal Infection

Question 1

What is Giardia?

Answer 1

• common parasite associated with hikers and campers from drinking unpurified water (cysts transmitted fecal orally).
• causes flatulence and foul-smelling diarrhea.
• STEATORRHEA (fatty stools)
• has distinct trophozoite form in stool.
• causes blunting of intestinal villi

Question 2

How do you diagnose Giardia?

Answer 2

• stool O and P culture -OR-

- ELISA stool antigen test

Question 3

How do you treat Giardia?

Answer 3

• metronidazole

Question 4

Can giardia be transmitted sexually?

Answer 4

• yes

Question 5

What animal is the host for giardia?

Answer 5

beaver

Question 6

What are the intestinal spore forming protozoa?

Answer 6

• cryptosporidia
• cyclospora
• isospora
• microspora

Question 7

What is important to know about cryptosporidia?

Answer 7

• causes severe diarrhea in HIV patients
• modified acid-fast stain to visualize
• infectious cysts are passed through watery stool
• cysts composed of 4 motile trophozoites
• comes from sewage run-offs, animal feces (fecal/water contamination).

Question 8

How to you treat cryptosporidia?

Answer 8

• nitazoxanide

- spiramycin (macrolide); not FDA approved

Question 9

What does cryptosporidiosis cause?

Answer 9

AIDS enteropathy= persistent nausea, vomiting, and diarrhea

Question 10

With what is cyclosporiasis associated?

Answer 10

imported raspberries and strawberries from Guatemala

Question 11

What is important to know about cyclospora?

Answer 11

• acid-fast
• fecal oral transmission
• life-threatening in AIDS
• cyst is larger in size than cryptosporidium

Question 12

What is important to know about Isospora (cystoisospora)?

Answer 12

• ELLIPTICAL oocysts
• eosinophilia and charcot-leyden crystals
• treat with TMP-SMZ

Question 13

What is important to know about Entamoeba histolytica?

Answer 13

• cyst form is infectious form
• associated with men who have sex with men
• right side of LIVER is most associated with amoebic liver abscess (RUQ pain with ANCHOVY PASTE consistency; amoebic hepatitis).
• can cause intestinal amebiasis (ulcerations in the colon with BLOODY DIARRHEA; amoebic dysentery).

Question 14

How do you diagnose Entamoeba histolytica

Answer 14

• O and P stool sample looking for trophozoites with endocytosed RBCs.
• intestinal biopsy may show FLASK or BOOT-shaped lesions.

Question 15

How do you treat Entamoeba histolytica?

Answer 15

• metronidazole -OR-

- PARAMYCIN or IODOQUINOL (luminal agents)

Question 16

What happens if you give a pt with amoebiasis, corticosteroids?

Answer 16

they can get toxic megacolon :(

Question 17

What is Microsporidiosis?

Answer 17

• opportunistic intestinal infection that causes diarrhea and wasting in immunocompromised individuals. Actually a fungi (was thought to be a protozoan).
• can cause cerebral microsporidiosis (spores in CSF).
• can cause KERATO-CONJUNCTIVITIS (dry eyes, ocular pain).

Question 18

What do we have to know about Balantidium coli?

Answer 18

• reservoir is PIGS
• lives in large intestine
• causes bloody diarrhea, abdominal pain, anorexia, colitis, weight loss, and fever