Infections Diseases - Parasitic Diseases Packet #1

Question 1

Three parasitic diseases associated with Immunosuppression

Answer 1

Giardia lamblia
Amebiasas
Cryptosporidiosis

Question 2

Four key determinants of parasitic disease

Answer 2

Malnourishment
Sanitation
Climate
Vectors

Question 3

What are protazoa?

Answer 3

Single celled organisms with complex cytoplasmic organelles. Most are motile. Most are fecal/oral (except the blood bournes like malaria + leishmaniasis)

Question 4

Amebiasis is caused by…

Answer 4

Entamoeba histolytica

Question 5

Pathophysiology of Amebiasis?

Answer 5

Infectious form (cysts) have cell wall to resist gastric acid
Trophozoites are amebic form.
They lyse colonic epithelial cells.
Only about 10% cause dysentery.

Question 6

Parts of the colon influenced by Amebiasis?

Answer 6

Cecum and Ascending bowel

Question 7

Amoeba look like what cell type?

Answer 7

Macrophages

Question 8

Describe what happens when Amebiasis trophozoites invade

Answer 8

Invade crypts of the colonic glands
Burrow through the tunica propria
Stuck at the muscularis mucosae

Question 9

Describe the lesions generated by Amebiasis

Answer 9

FLASK SHAPED ULCERS with narrow neck and broad base
Mucosal cells above it slough due to ischemia
Neutrophils enter–>liquefactive necrosis

Question 10

Chronic damage in Amebiasis may lead to what features of the lesions

Answer 10

Napkin like constrictive lesion similar to colonic carcinoma due to extensive fibrosis

Question 11

Relationship of Amebiasis and the liver

Answer 11

In 40%, parasites penetrate portal vessels
make AMEBIC ABSCESSES in the liver
possibly pain on palpation

Question 12

Treatment for Amebiasis?

Answer 12

Metronidazole. It targets ferredoxin-dependent pyruvate-oxioreductase, preventing glucose fermentation.

Question 13

Most prevalent pathogenic intestinal organism worldwide

Answer 13

Giardia lamblia

Question 14

How to remove Giardia lamblia?

Answer 14

Filtration

Question 15

Giardia lamblia is spread by…

Answer 15

Fecal/Oral

Common in day care centers, institutions for mentally retarded

Question 16

Giardia lamblia is associated with what immune defect?

Answer 16

IgA deficiency
(Also common in AIDS patients)

Question 17

Pathogenesis of Giardia lamblia?

Answer 17

Trophozoites multiply in SI, attach but don’t invade

DIARRHEA, NOT DYSENTERY

Question 18

What causes the diarrhea of Giardia lamblia?

Answer 18

Alterations in nutrient malabsorption

NOT excess electrolyte secretion

Question 19

How does Giardia lamblia bind SI?

Answer 19

Concave attachment disc

Question 20

How does Giardia lamblia block nutrient absorption?

Answer 20

Blocked mucosal Surface

Samage to microvilli

Question 21

Characteristic morphology of Giardia lamblia trophozoites?

Answer 21

Cartoon ghost

Question 22

Abnormalities of mucosa seen in Giardia lamblia infection?

Answer 22

Clubbing of villi
Mixed inflammatory infiltrate in lamina propria
In IgA deficient – follicular hypertropy of mucosal lymphoid tissue

Question 23

Giardia lamblia is treated with…

Answer 23

Metronidazole (same reason as Amebasis)

Question 24

Cryptosporidiosis is caused by

Answer 24

Cryptosporidium parvum

Question 25

Symptoms of Cryptosporidiosis?

Answer 25

Tranisent, Watery Diarrhea More common in Kids Severe in IC

Question 26

Difference between Cryptosporidiosis, Giardia, and amebae in AIDS patient.

Answer 26

While they're all there more commonly, disease is no more severe with IC patients than mormal. Cryptosporidiosis causes a much worse disease state in AIDS patients.

Question 27

How is Cryptosporidiosis cleared from water

Answer 27

filtration

Question 28

Only parasite with sexual resproduction in host

Answer 28

Cryptosporidiosis

Question 29

Pathogenesis of Cryptosporidiosis

Answer 29

Sporocytes adhere to colonic epithelium Malabsorption and secretory diarrhea Invasion, Infection of Macro. and Peyer's patches

Question 30

What immune cell is required to control Cryptosporidiosis?

Answer 30

CD4

Question 31

Symptoms in Immunocompetent patient of Cryptosporidiosis?

Answer 31

Diarrhea and Vomiting for 3-14 days

Question 32

What part of the bowel tends to get Cryptosporidiosis?

Answer 32

Jejunum+Ileum | Sometimes colonic

Question 33

Only Ciliated protozoan to infect humans?

Answer 33

Balantidiasis

Question 34

Effects of Balantidiasis

Answer 34

Ciliary dysentery

Question 35

Where is Balantidiasis

Answer 35

Rare in US, common worldwide (mostly tropics) | Exists wherever pigs are

Question 36

How do Balantidiasis ulcers look different from E. histolytica?

Answer 36

Remain localized to the cecum and sigmoidorectal areas

Question 37

Balantidiasis. How to diagnose?

Answer 37

Stool trophozoites

Question 38

Treatment for Balantidiasis?

Answer 38

Tetracycline | Iodoquinal

Question 39

How to diagnose entamoeba histolytica?

Answer 39

Stool/Aspirates trophozoites or cysts

Question 40

How to treat entamoeba histolytica?

Answer 40

Metranidazole, Iodoquinal

Question 41

How to diagnose Giardia?

Answer 41

Cysts/trophozoites in stool | Biopsy, String Test

Question 42

How to treat Giardia?

Answer 42

Metronidazole, Furazolidone

Question 43

How to diagnose Cryptosporidium parvum?

Answer 43

Biopsy, Fecal smears | String Test

Question 44

How to treat Cryptosporidium parvum?

Answer 44

Spiramycin

Question 45

How to diagnose Trichomoniasis?

Answer 45

Demonstrate motile trophozoite on discharge smear

Question 46

Treatment for Trichamoniasis?

Answer 46

Metronidazole

Question 47

Pathogenesis of Trichamoniasis?

Answer 47

Mild reaction that can allow secondary bacterial infection | In alkaline female conditions --> profuse, watery leukorrheic discharge with pruritis of the vagina + vulva

Question 48

pathology of Trichamoniasis?

Answer 48

Strawberry Mucosa - Spotty reddening of mucosa with small papulaes/blisters Mixed inflammatory cell infiltrate Turnip shaped trichamonads visible in fresh discharge prep