Introduction Parasitology/Entomology

What are the 5 infection types?

Bacteremia, Toxemia, Septicemia, Viremia, Parasitemia

Define Bacteremia

Bacteria spread through host blood/tissues

Define Toxemia

Toxins produced from bacteria spread in blood/tissue; overwhelm body

Define Septicemia

Multiplying bacteria, bacterial wastes, dead host cells, and other toxins spread in host’s blood

Define Viremia

Spread of a virus through host blood/tissue

Define Parasitemia

Spread of parasitic organisms in host

Define acute infection

An infection that is quick to become symptomatic after exposure and is short lived.

Define chronic infection

An infection that develops more slowly over time and is long-lived. Cumulatively debilitating with the occasional “acute phase” where the pathogen “wakes up” and re-infects the host

What are common modes of infection?

Direct contact w/infected (skin-skin, bite, touch wound etc), direct ingestion, fomites, vectors, trans-placental, trans-mammary, airborne/droplets, contaminated food/water/environment/soil, autoinfection, and via intercourse

Define MECHANICAL vector

Transmits DIRECTLY w/out prior development of parasite

Define BIOLOGICAL vector

Infectious organism develops outside of host prior to infection

Define direct life cycle

Parasite only needs ONE host to complete full life cycle

Define indirect life cycle

Parasite needs MULTIPLE hosts to develop before reaching the final host

Define vector

An animal, commonly an arthropod, that transmits an infective organism from one host to another

How may parasites be categorized based on location and behavior?

Endoparasites (INside), Ectoparasites (OUTside), Obligate (REQUIRE host), Facultative (opportunistic, not 100% parasitic), & host-specific (ONLY specific host—won’t infect others)

What are the different categories of hosts?

Definitive, Paratenic, Dead-End, Intermediate, and Reservoir

Define definitive host

A host of the adult/sexually reproductive stage of the parasite; generally invertebrates

Define paratenic host

Harbors parasite as temporary transport/refuge vehicle for sexually immature stages that DO NOT DEVELOP; non-essential

Define reservoir host

Any host aside from host of interest where parasites undergo active development on the way to the host of inerest. Essential to parasite’s life cycle; source of infection to those susceptible.

Define intermediate host

A host REQUIRED for the development of intermediate/larval stages.

What are the types of zoonosis?

Antrozoonosis, Zooantroponosis, Anthroponosis, Cyclozoonosis, Metazoonosis, Saprozoonosis, Zootherinosis, & Zootithasonosis

Define antrozoonosis

Animal infects human

Define zooantroponosis

Human infects animal; “reverse zoonosis”

Define Amphixenosis

An infection interchangeable/shared between humans and other vertebrates

Define Cyclozoonosis

Zoonosis in VERTEBRATES ONLY

Define Metazoonosis

Agents which cycle between vertebrates and non-vertebrates

Define Saprozoonosis

Agents cycle between vertebrates and non-animal hosts

Define Zootherinosis

Wild animal infects domestic animal

Defime Zootithasonosis

Domestic animal infects wild animal

What are the 7 major parasite groups?

Insects, Arachnids, Nematodes, Cestodes, Termatodes, Protozoa, & Acanthocephala