Parasitism and infectious Diseases Vocabulary

Parasite

An organism that lives in or on a host and consumes their resources, causing harm to the host

Pathogen

A type of parasite that causes infectious disease

Ectoparasites

Parasites that live on the outside of an organism

Endoparasites

Parasites that live inside organisms

Intracellular

Endoparasites that live inside the cells of a host

Intercellular

Endoparasites that live in spaces between the cells of a host

Emerging Infectious Disease

A newly discovered or rare disease that increases in abundance

Horizontal Transmission

When a parasite moves between individuals other than parents and offspring

Vertical Transmission

When a parasite is transmitted from a parent to its offspring

Vector

An organism that disperses a parasite between hosts

Infection Resistance

Ability of the host to prevent infection from occurring

Infection Tolerance

Ability of the host to minimize harm from the infection

Susceptible-Infected-Resistant (S-I-R) Model

The simplest model of infectious disease transmission that incorporates immunity

Reproductive Ratio (R0)

The ratio of new infections to recoveries

Coevolution

When two or more species continue to evolve in response to each other’s evolution