Chapter 14- Parasitism and Infectious Diseases

Infection Resistance

The ability of a host to prevent an infection from occurring.

Infection Tolerance

The ability of a host to minimize the harm once an infection has occurred.

Parasite Load

The number of parasites of a given species that an individual host can harbor.

Ectoparasite

A parasite that lives on the outside of an organism.

Endoparasite

A parasite that lives inside an organism.

Common Ectoparasites

Examples include nematodes, fleas, lice, mites, and ticks.

Emerging Infectious Disease

A disease that is newly discovered or has been rare and then suddenly increases in occurrence.

Horizontal Transmission

Parasite moves between individuals other than parents and offspring.

Vector

Another organism that disperses the parasite from one host to another, sometimes involving multiple hosts.

Vertical Transmission

A parasite moved from a parent to its offspring.

Reservoir Species

Species that can carry a parasite but do not succumb to the disease that the parasite causes in other species.

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

The simplest model of infectious disease transmission that incorporates immunity.

Host Adaptations

Strategies evolved by hosts to defend against parasites, such as avoidance of infected feces, removal of ectoparasites, and production of anti-fungal or antibacterial chemicals.