Lecture 5: Tapeworms Flashcards Preview

MEDS 527 : Zoonotic Final > Lecture 5: Tapeworms > Flashcards

Flashcards in Lecture 5: Tapeworms Deck (50)
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1

What is the name given to a class of parasitic flatworms, commonly called tapeworms

Cestodes

2

Cestodes are live in the _______ of vertebrates

digestive tract

3

T/F

1000 species belong to the Cestodes class of parasites wide a wide range of animal hosts

True

4

Life cycle of Echinococcosis involves what number of mammalian hosts

2

5

______ are the definitive hosts of Echinococcosis

Carnivores

6

___________ harbor the adults which shed eggs within their feces

“Definitive hosts”

7

Eggs hatch when ingested by ________ hosts, including goats sheep cattle

intermediate

8

Life cycle of Echinococcosis
completed when ______________

definitive hosts reingest the organ tissue of intermediate hosts which contain eggs aka cysts

9

Disease caused by Echinococcosis is caused by how many species in humans?

four species in humans

10

What are the two most common species of Echinococcosis in humans?

E granulosus and E multilocularis are most common
- Causes cystic echinococcosis and alveolar echinococcosis respectively

11

What are the two least common species of Echinococcosis in humans?

E vogeli and E oligarthrus are also pathogenic but are much less common in humans

12

_______ forms are referred as hydatid cysts and the diseases caused by them are commonly referred as cystic, alveolar, or polycystic hydatid disease

Metacestode (larval)

13

Metacestode (larval) refer to ______________

hydatid cysts and the diseases caused by them are commonly referred as cystic, alveolar, or polycystic hydatid disease

14

The fully grown metacestode in E. granulosus is typically ____________

fluid filled and unilocular

15

T/F

In humans the slowly growing hydatid cysts many contain many liters of fluid and thousands of protoscolices

True

16

E. Granulosus causes ____________

cystic Echinococcosis

This form is most frequently encountered

17

E. Granulosus is distributed

worldwide

18

E. Granulosus is most frequently in what areas?

Areas of rural side where sheep raising occurs

19

E. Granulosus is how long and has what features?

3-mm

Rostellum contains 28-50 hooks

20

Definitive host of E. Granulosus

Dogs and other carnivore

21

Intermediate host of E. Granulosus

Sheep, goats, camels, horses, cattle

22

Incidental host of E. Granulosus

Human (do not play a role in transmission)

23

T/F

A heavily infected dog may have as many as 40,000 tapeworms and each worm sheds 1000 eggs every 2 weeks

True

(Eggs can adhere to hair around dog anus and also around the muzzle of the )

24

T/F

Eggs can survive on pasture > 1 year and survive scorching temperatures

F

Eggs can survive on pasture > 1 year and survive FREEZING temperatures

(Die off after a few hours of direct sunlight)

25

Describe life cycle of E. Granulosus

1. Adult worm inhabits small intestine of definitive host
2. Following egg ingestion by the intermediate or incidental host, eggs hatch and penetrate the intestinal mucosa and enter the blood stream
3. A few days later, cysts start to form and grow with time

26

E. multilocularis causes _________ that looks like alveoli

alveolar Echinococcosis

(Can travel to any part of the body, like cancer and are 1.2 mm-3.7 mm long)

27

Definitive and intermediate Host of E. multilocularis

Definite host: mainly foxes but dogs, cats, coyotes and wolves also
Intermediate Host: small rodents

28

E. multilocularis is found in what geographical type of countries?

Mostly found in northern countries, cooler temperature countries
(Associated with dogs feeding on infected rats)

29

T/F
Clinical manifestations of Echinococcus are similar.

False

Clinical manifestations are highly variable

- Depends on the organs involved and surrounding organs
- Size of the cysts at time of presentation

30

T/F

There are no immunological reactions to the parastic antigens of Echinococcus

False

- Immunological reactions to the parasitic antigens
- Noticed once the lesions start to cause discomfort/pain
- Typically presents with RUQ pain and liver symptoms