Parasitic infections of the GI and GU tracts

Question 1

What is a parasite?

Answer 1

organism that lives on or in a host and gets its food from or at the expense of its host

Question 2

How are protozoa classified?

Answer 2

according to their movement

Question 3

What are the 4 classifications of protozoa?

Answer 3

sacromastigophora; apicomplexa; ciliophora and microspora

Question 4

What are hte further divisions of sacromastigophora?

Answer 4

sarcodina and mastigophora

Question 5

How do sarcodina move?

Answer 5

by pseudopodia

Question 6

What characterises sarcomastigophora?

Answer 6

flagellae; pseudopodia or both

Question 7

Give an example of a sarcodina?

Answer 7

entamoeba

Question 8

What is a mastigophora?

Answer 8

move by flagella

Question 9

Give an example of a mastigophora?

Answer 9

giardia

Question 10

What defines an apicomplexa?

Answer 10

no organelle of locomotion

Question 11

Give an example of an apicomplexia?

Answer 11

plasmodium

Question 12

What defines ciliophora?

Answer 12

move by cilia

Question 13

Give an example of ciliophora?

Answer 13

balantidium

Question 14

What defines microspora?

Answer 14

spore-forming

Question 15

Give an example of a microspora?

Answer 15

entercytozoa

Question 16

What are the 2 phyla of metazoa?

Answer 16

nematodes and platyhelminithes

Question 17

What are nematodes?

Answer 17

round worms (tubes)

Question 18

What are the 2 classes of platyhelminthes?

Answer 18

cestodes and trematodes

Question 19

What are platyhelminithes?

Answer 19

flat worms-dorsoventrally flattened

Question 20

What are the differences between cestodes (tapeworms) and trematodes (flukes)?

Answer 20

cestodes are segmented by have no alimentary canal whereas trematodes are non-segmented with 2 suckers and no head but have an alimentary canal

Question 21

Give an example of a cestode?

Answer 21

taenia

Question 22

Give an example of a nematode?

Answer 22

roudnworm-ascaris

Question 23

Give examples of trematodes?

Answer 23

fasciolopsis; schistosoma

Question 24

What are the RFs for getting GI parasitic infections?

Answer 24

infected water or food; immunosuppression; nutritional deficiency; foreign travel; oro-anal intercourse

Question 25

What are the 4 anatomic locations of GI parasites?

Answer 25

lumen only; mucosal attachment; epithelial cell invasion; mucosal invasion

Question 26

Give an exmaple of a parasite which remins in the lumen only?

Answer 26

ascaris ; entamoeba

Question 27

Give an example of parasites which attach to the mucosa?

Answer 27

giardia lamlia; tapeworm

Question 28

give an exmple of parasites which invade the epithelia?

Answer 28

microsporidia

Question 29

Give an example of a parasite whic hinvades the mucosa?

Answer 29

balantium coli

Question 30

What is the infective dose required for giardia?

Answer 30

very low- 10-25 cysts

Question 31

How do giardia multiply?

Answer 31

by binary fission

Question 32

How do giardia trophozoites attach to the intestines?

Answer 32

attach to villi by ventral sucking disk

Question 33

How does giardia cause diarrhoea?

Answer 33

attachment physically disrupts intestinal absorption

Question 34

What causes giardiasis?

Answer 34

giardia lamblia

Question 35

What causes amoebiasis?

Answer 35

entamoeba histolytica

Question 36

What is the infecitous form of giardia?

Answer 36

cyst form

Question 37

What are teh 3 forms of amoebiasis disease?

Answer 37

carrier; intestinal or extra-intestinal

Question 38

What are the features of intestinal amoebiasis?

Answer 38

abdo pain; colitis- flask shaped ulcers and bloody diarrhoea

Question 39

What are the features of extra-intestinal amoebiasis?

Answer 39

liver; lung and brain abscesses- fever; leukocytosis and rigors

Question 40

Where is cryptosporidiosis found in the intestines?

Answer 40

brush border of the intestinal epithelium

Question 41

How do cryptosporidia replicate?

Answer 41

schizogony- asexual

Question 42

What is the infectious agent in cryptosporidiosis?

Answer 42

thick walled oocyst (sporulated)

Question 43

What are the symptoms of trichomoniasis?

Answer 43

watery discharge

Question 44

How does trichomonas replicate?

Answer 44

longitudinal binary fission

Question 45

What is the most common helminithic infection worldwide?

Answer 45

ascariasis

Question 46

What is found in the ascaris eggs infested by humans?

Answer 46

larval worm

Question 47

What happens when the ingested eggs of ascaris are released?

Answer 47

penetrates the duodenal wall; enters the bloodstream, liver, heart and pulmonary cicrulation

Question 48

What is the feature of ascariasis in the lungs?

Answer 48

hypersensitivty penumonitis resembling an asthmatic attack

Question 49

what is the tx for ascariasis?

Answer 49

mebendazole

Question 50

What is the function of preserving faecal specimens in 10% formalin?

Answer 50

preserves parasitic morphology

Question 51

What is used for giardia detection in stoll samples?

Answer 51

ELISA

Question 52

What is saline wet mount examination sued for identification of?

Answer 52

trophozoites; cysts of protozoa; ova/larvae of helminths

Question 53

What is iodine wet mount used for identification of?

Answer 53

protozoal cysts

Question 54

What type of drug is generally used for parasitic infections?

Answer 54

"azole" drugs

Question 55

What drug is used for most protozoa?

Answer 55

metronidazole