Parasitology Intro Terminology

A close association (symbiosis) between two different species of organisms, one of which, the Parasite, depends on the other, the Host, deriving some benefit from it without necessarily damaging it

The course of developmental changes through which an organism passes from its inception as a fertilized zygote to the mature state in which another zygote may be produced

A parasite is transmitted directly from on definitive host to the next without an intermediate host

An intermediate host is required for the transmission of a parasite form one definitive host to the next (two type of host involved)

The host in which the parasite reaches maturity and undergoes SEXUAL REPRODUCTION ( can be vertebrate or invertebrate)

Ordinarily, a necessary host and one in which only the asexual or immature states occur (can be vertebrate or invertebrate)

An infected animal serving as a source from which other animals can become infected

A POTENTIAL host (does not have to be) in which there is NO REQUIRED development of the immature parasite but the organism remains infective for the definitive host (also called a transport host)

Parasite in unusual or abnormal host (also called incidental or aberrant host)

the presence of parasites within a host

time during which developmental stages of parasites have not been produced to give evidence (such as eggs/oocysts) of their presence

point at which infectious/ parasitic agent produced evidence (such as eggs, larvae, or oocysts) of their presence

a specific morbid process that has a characteristic set of signs; may affect either the entire body or any part of the body

Can measure the signs

Cannot measure the signs of disease/ does not have any signs of disease

• The ability to cause disease:
• Number of parasites
• Strain or spp. of parasites
• Host immune status

Invasion by parasites (generally restricted to ectoparasites) Outside the body

The parasites are inside the body