2-33 Introduction to Parasitic Diseases Flashcards Preview

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Flashcards in 2-33 Introduction to Parasitic Diseases Deck (26)
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1

why do we have a harder time clearing parasitic diseases compared to bacterial or viral?

1. the life cycles of parasites are short and express different antigens

2. antigen mimicricy - parasite expresses epitopes similar to host molecules

3. antigenic shedding - shed antigens to conceal from immune system

4. antigenic variation - generate novel antigens by random mutations

5. antigen concealment - antigen hides antigens by being intracellular

2

obligate parasite

completely dependent on host, can't survive without it

3

facultative parasite

Can change its life style between free-living in the environment and parasitic according to the surrounding conditions and does not absolutely require a host for survival

4

accidental parasite

Affects an unusual host (e.g. Toxocara canis (a dog parasite) in man).

5

temporary parasite

vists the host only for feeding and then leaves

6

permanent parasite

lives in/on host without leaving until removed (lice, crabs)

7

opportunistic parasite

Capable of producing disease in an immunodeficient host (like AIDS and cancer patients). In the immuno-competent host, it is either found in a latent form or causes a self-limiting disease (e.g. Toxoplasma gondii).

8

zoonotic parasite

Primarily infects animals and is transmittable to humans (e.g. Cryptosporidium parvum).

9

many parasitic infections are characterized by...

eosinophilia and high levels of IgE

normal eosinophil levels are 1-2%
parasitic infection - 10-15%

10

describe the role of IgE in parasitic diseases

IgE binds mast cells and basophils. When specific antigen-antibody combos occur, mast cells degranulate and releases chemotactic factors, histamine, prostaglandinds, and other mediators.

11

what does eosinophil chemotactic factor do?

attracts eosinophils to infected areas

12

#1 parasite worldwide?

malaria

13

highest mortality rates to parasites?

children under 5

14

what caused the decrease in hookworm infections?

wearing shoes

15

parasites don't often kill hosts (TF)

True, except malaria

16

what has caused the spread of parasites to new areas?

-global warming = parasite range increasing. Along with human behavior and population movement

17

Chagas disease

infected with tryponosoma cruzi via reduviid bug

18

cysticercosis/neurocysticercosis

caused by larval pig tapeworms (taenia solium)
-frequent cause of seizures in low-income countries


wild boar/pigs are resovoir
creates significant lesions in brain that cause destruction

19

toxocariasis

found in cats and dogs

humans accidentally ingest eggs, parasite tries to exit incorrect host via the retina

20

toxoplasmosis

cat feces and undercooked meat

In particular stage of pregnancy, crosses placenta to enters fetus that leads to several issues.

21

trichomoniasis

an STI, 85% asymptomatic, can cause Pelvic Inflammatory Disease

22

ectoparasite

parasite lives on outside of host

23

endoparasite

parasite that lives within the host. ussually helminths

24

definivite Vs intermediate host

definitive - parasite can multiply within the host

intermediate - most human parasites, host harbors the larval or sexually inmmature form

25

most parasites enter humans through

injestion of eggs

26

parasitic infections are ussually diagnosed through

direct examination of feces, urine, blood, or tissue.

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