Basic Terminology

Question 1

Parasitology

Answer 1

The study of parasites.

Question 2

Parasite

Answer 2

Organisms that live on (ectoparasite) or in (endoparasite) an animal, deriving their nutrition and protection at the expense of the animal. They are primarily programed to reproduce.

Question 3

Obligate Parasite

Answer 3

Require a host. Can survive outside the host only for a short time.

Question 4

Facultative Parasite

Answer 4

Can live on or off the host.

Question 5

Host

Answer 5

The animal supporting the parasite.

Question 5

Definitive Host

Answer 5

Harbors the a_D_ult form of the parasite (primary host).

Question 6

Intermediate Host

Answer 6

Harbors the _I_mmature form of the parasite. Development takes place within the intermediate host (secondary host).

Question 7

Paratenic Host

Answer 7

May harbor adult or immature form. No development takes place on this host; it is not the normal host (transport host).

Question 8

Commensal Parasite

Answer 8

Not harmful to the host, may be “normal” fauna of the inhabited host system.
-ex: Skin mites in certain species. Bacteria found in rumen/cecum which help in fermentation.

Question 9

Obligate Parasite

Answer 9

The parasite is obligated or it is necessary for the parasite to live on the host (or during that stage of development). This form will not be found free living (for extended periods).
-ex: fleas

Question 10

Ectoparasites

Answer 10

Live on or parasitize superficial structures or skin of the host. This is usually the adult form.
-ex: fleas

Question 11

Endoparasites

Answer 11

Live in or parasitize an internal site or organ system. Usually identified by examining feces to detect the ova of the organism.
-ex: intestinal parasites

Question 12

Infection

Answer 12

An internal inhabitation by a parasite, also any parasitic organism.
ex: bacteria, fungal agents
Endo

Question 13

Infestation

Answer 13

An external inhabitation by a parasite.

Ecto

Question 14

Homoxenous

Answer 14

A parasite which utilizes 1 host species. Host specific.

-ex: Lice are species specific. Cat lice only infest cats.

Question 15

Heteroxenous

Answer 15

Utilizes more than 2 hosts during normal development (life cycle). Must us an intermediate host.
-ex: dipylidium [flea tapeworm] primary/definitive host is cat or dog, intermediate host is the flea.

Question 16

Parasitic Impasse

Answer 16

A parasite is located in an abnormal site, or wrong host, which prevents normal development of the parasite from progressing. It may or may not be detrimental to the host. The host is a dead end.

• ex: ingestion of canine ascarid [roundworm] larvae by humans. Larval migration can cause severe tissue damage.
• ex: heartworm in humans, skin rashes.