Parasites

Question 0

Types of parasites

Answer 0

Obligatory
Facultative
Accidental (toxocara)
Temporary (feeding)
Permanent
Opportunistic

Question 1

Neglected parasitic infections in the us

Answer 1

Chagas disease: kissing bug, blood meal releases trypomastigotes
Cysticercosis: pig tapeworm
Toxocariasis: roundworms on dogs/cats; get out through eyes
Toxoplasmosis: protozoan parasite in cats, pregnant woman to unborn child
Trichomoniasis: sexual transmission, no symptoms in women

Question 2

Definitive v intermediate hosts

Answer 2

Definitive harbors adult or sexually mature stages of parasite

Intermediate harbors larval or sexually immature stages

Question 3

Ectoparasite v endoparasite

Answer 3

Lives on outside of host (feeding)

Lives within body of host (intestinal, arterial, tissues)

Question 4

Parasitic Protozoa v parasitic helminths

Answer 4

Unicellular (ameba, flagellates, ciliates, sporozoa)

Multicellular (nematodes, etc)

Question 5

Parasitic transmission

Answer 5

Direct ingestion of infected larvae, eggs, cysts
Eating intermediate host
Parasite actively penetrating host
Maternally
Vector borne transmission (blood meal)

Question 6

Pathogenesis

Answer 6

GI, blood borne, tissue infections
Usually chronic vs short term for bacterial or viral
Disease usually due to immune response
May remain dormant

Question 7

Immune response

Answer 7

Innate response: many different genetic and antigenetic variations
Adaptive response: IgE eosinophil

Question 8

Survival strategies against immune response

Answer 8

Complicated life cycle make effective immune response difficult
Antigenic mimicry: incorporation of host self antigens into surface
Antigenic shedding: shedding of surface antigens or components
Antigenic variation: gene switching
Antigenic concealment: intracellular survival within macrophages