Overview
Normal functioning of the immune system protects the body against the inva-
sion of outside microorganisms referred to as a pathogen.Two of the most
common pathogens are bacteria and viruses. An infection occurs when there
is a successful invasion of the host by a pathogen (antigen). However, for this
to happen, each link in the chain of infection must be intact.Chain of Infection
The chain of infection describes the elements that must be in place for the
infection to occur. These elements are
Pathogen: Sufficient number of microorganisms strong enough to enter
and survive the body.
Reservoir: The proper environment within the body to prosper must
include oxygen, water, food, and the best pH balance and temperature.
Portal of exit: The pathogen must be able to exit its existing environment.
For example, the pathogen must be able to leave the respiratory tract, gas-
trointestinal (GI) tract, or skin of its present host to infect another host.
Mode of transmission: There must be a way for the pathogen to move
from one host to another such as by air droplets, water, or contact.
Portal of entry: The pathogen must be able to enter the new host such as
through a break in the skin or via the respiratory tract.(^302) Pediatric Nursing Demystified
12 Determine who can visit a patient who has varicella.
13 Respond to a patient who has anaphylaxis.
14 Assess the signs and symptoms of mononucleosis.
Allergen
Artificially acquired active
immunity
Artificially acquired passive
immunity
Brudzinski sign
Contact isolation
Droplet isolation
Endotoxins
Exotoxins
Flora
Forescheimer spots
Incubation period
Kernig sign
Koplik spots
Macules
Myalgias
Natural immunity
Naturally acquired active
immunity
Naturally acquired passive
immunity
Papules
Parotitis
Pathogen
Prodromal
Toxoids
Urticaria
Vesicles