Lecture 19 Flashcards Preview

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Flashcards in Lecture 19 Deck (66):
1

Types of Metazoa parasites

cestodes, trematodes, nematodes

2

What are cestodes?

tape worms

3

How many parts do tape worms have?

2- rounded head and flat body of multiple segments

4

What is the rounded head of the tape worm known as?

Scolex

5

What is the flat body of multiple segments of the tape worm called?

proglotids

6

What is the host of tape worms?

human

7

4 types of tape worms?

pork, beef, fish, and dog tape worms

8

What do pork tape worms cause?

disease known as cysticircosis in humans

9

Define cysticerci

name of larvae in pork

10

What happens when humans swallow eggs?

larval form cysticerci develop in various organs like brain and eye where they encyst

11

What will happen when the cysticerci is in brain

mimic brain tumors and causes headache, vomiting, seizures

12

What will happen when cysticerci is in the eye?

may cause uveitis and retinitis

13

Where is the pork tape worm most common?

Asia, S. America and eastern Europe

14

Treatment for adult pork tape worms

Praziquintal

15

Treatment for cysticercosis from pork tape worms

surgical excision

16

Transmission of beef tape worm

humans infected by eating under cooked beef containing larvae

17

Who is the host of beef tape worm?

human

18

Who is the intermediate host of beef tape worm?

cattle

19

Where is beef tape worm commonly found?

Africa, S. America and Eastern Europe

20

Clinical features of beef tape worm?

adult worms do not cause symptoms- proflatids protrude through anus

21

Treatment for beef tape worm?

Praziquental

22

Transmission of fish tape worm?

eating raw/uncooked fish containing larvae

23

Symptoms for adult worm fish tape worm

asymptomatic- may produce anemia due to B12 deficiency

24

What does dog tape worm cause?

hydatid cyst in humans

25

Who is the definitive host in dog tape worm?

dog

26

What is the intermediate host for dog tape worm?

sheep

27

What is the dead and intermediate host of dog tape worm?

human

28

Transmission of dog tape worm

worms in the dog liberate thousands of eggs- ingested by sheep or human and embryo emerges into intestine and migrates to liver, lung, bone and brain

29

Where do the large fluid filled hydatid cyst develop in the body?

brain, lung, liver

30

What does hydatid cyst cause?

causing pressure effects on tissue

31

Treatment of dog tape worm

surgical removal to prevent accidental dissemination- hypertonic saline injection used

32

Life cycle of trematodes?

a sexual cycle (in humans) and an asexual reproduction in freshwater snails (intermediate host_

33

Transmission of trematodes to human

occurs either through penetration of skin by free-swimming larval form (cercaria) or via ingestion of cysts

34

What is the name for free-swimming larval?

cercaria

35

What are the two things that schistosoma effects?

GIT and urinary tract- the forms exist as separate sexes

36

Where do S. mansoni and S. Japanicum live?

in mesentric veins draining the intestines

37

Where do S. Hematobium live?

in pelvic veins draining the bladder

38

What is the size of an adult Schistosoma worm

1-4 inches

39

How does human infection of Schistosoma occur?

in water- when you swim in ponds or lakes- penetrate legs and enter blood circulation to reach liver

40

Clinical manifestations of Schistosoma?

most are asymptomatic- granulomas in liver, portal hypertension, enlarged liver and spleen, GI bleeding, granulomas in bladder causing hematuria

41

How do you diagnose Schistosoma in the lab?

finding characteristic eggs in stools

42

Treatment for Schistosoma

Praziquental

43

What are Nematodes?

round worms

44

2 types of Nematodes

intestinal and tissue nematodes

45

Describe what Nematodes look like?

have cylindrical body with complete digestive systems from mouth to anus- body has acellular resistant coating- female larger than male, 2 larval forms!

46

What is the host for nematodes?

human

47

Intermediate host for Nematodes?

NONE

48

What do Nematodes cause?

eosinophilia and allergy

49

What are enterobius vermicularis?

pin/thread worm

50

Transmission of enterobius vermicularis

eggs are ingested- hatch in small intestines and migrate to colon

51

Who is enterobius vermicularis common in?

children

52

Clinical manifestations of Enterobius vermicularis?

perianal pruritus, scratching

53

What country is Enterbius vermicularis most common in?

US

54

Lab diagnosis for Enterobius vermicularis

eggs not found in stool- may be in perianal scrapings
adult worms can be seen in stool or diapers

55

Treatment for Enterobius vermicualris

Mebendazol or pyrental palmoate

56

What type of worm is Ascaris lumbricoides?

round worm

57

How does human infection of Ascaris lumbricoides occur?

ingestion of egg in soil contaminated with human feces hatch in small intestines and larvae spreads through blood stream

58

Where can Ascaris lumbricoides be found?

in intestinal lumen- not attached to walls- live on ingested food

59

Clinical manifestations of Ascaris lumbricoides

larval migration through lungs causes eosinophilia, chronic bronchitis and cough

60

What can adult round worm cause?

malnutrition

61

Where are Ascaris lumbricoides common?

in tropical countries

62

Lab diagnosis of Ascaris?

detection of eggs ins tools- sometimes adult worms are passed in stools

63

Treatment for ascaris?

Mebendazol and pyrantel palmoate

64

Prevention for Ascaris?

proper disposal of night soils

65

What are the two types of Hook worms?

Ankylostoma duodenale, necator americanus

66

Transmission of hook worm?

attaches to gut wall and sucks blood, worm produces anticoagulants which prevent clotting- can produce anemia if enough blood loss