HLTH module 3: infection Flashcards
when does an infection occur?
when a microbe or parasite is able to reproduce in or on the body’s tissues
reservoir
the source of infection
direct contact of infection
occurs for microbes in the blood, body secretions or a lesion
what is the cause of syphilis?
treponema pallidum
what is the cause of toxoplasmosis
toxoplasma gondii; results in many neurologic effects
how can indirect contact from injection occur?
involves an intermediate object such as a contaminated food or hand that carry organisms
droplet transmission
can be oral or respiratory and occurs when respiratory or salivary secretions containing pathogens are expelled from the body and then transferred to another person
aerosol transmission
involves small particles from the respiratory tract that remain suspended in the air and travel on air currents, infecting any new host that inhales the particles
vector-borne
occurs when an insect or animal serves as an intermediary host in a disease such as malaria
nosocomial infections
those that occurs in health care facilities such as hospitals, nursing homes, doctors offices, and dental offices
interferons
proteins produced by human host cells in response to viral invasion of the cell; these influence the activity of nearby host cells, increasing their resistance to viral invasion
factors that decrease host resistance
age (infants and elderly), genetic susceptibility, immunodeficiency, malnutrition, chronic disease, severe stress, inflammation or trauma affecting the skin or mucosa, and impaired inflammatory response
pathogenicity
the capacity of microbes to cause disease
virulence
the degree of pathogenicity of a specific microbe
factors that virulence is based on
invasive qualities, toxic qualities, adherence to tissue, and the ability to avoid host defences
toxic qualities
the production of enzymes, exotoxins, and endotoxins that damage host cells
how can microbes avoid host defences?
frequent mutations which cause antibodies to no longer be effective, so the individual is no longer protected
how can microbes adhere to tissues?
by pili, fimbriae, capsules, or specific membrane receptor sites; certain organisms tend to establish infection in particular areas of the body that are hospitable to that microbe
methods for controlling infection
locating and removing the reservoir, blocking the portal of exit of microbes, knowledge of the mode of transmission, adequate cleaning of surrounding (includes sterilization, disinfectants, and antiseptics)
universal precautions
provide the basic guidelines by which all blood, body fluids, and wastes are considered ‘infected’ in any patient regardless of their conditions; two levels (general and specific)
antisepetics
antimicrobial chemicals designed to be used on living tissue, ex. isopropyl alcohol or hand sanitizer
sterilization
complete destruction/removal of all microorganisms by exposure to heat; ex. autoclaving
disinfectants
chemical solutions designed to be used on living surfaces that destroy microorganisms and their toxins
incubation period
the time that the body is exposed to the organism and the appearance of clinical signs, these vary lots; the organism is producing lots until there are sufficient number to cause adverse effects in the body
prodromal period
the period of early symptoms when the infected person may feel fatigued, lose appetite, or have a headache; ‘im coming down with something’
acute period
period when the infectious disease develops fully and the clinical manifestations reach a peak; time varies based on pathogen and host resistance
convalescent period
the period of recovery when signs subside and body processes return to normal
4 stages of infection
incubation period, prodromal period, acute period, and convalescent period
local infection
organism enters the body and remains confined to a specific location
focal infections
pathogen spreads from a local infection to other tissues