Infection, Asepsis & Sterile Technique

Microorganisms

Microscopic living cells found almost everywhere in the environment

Microorganisms that cause diseases are called…

Pathogens

Factors that affect growth of microorganisms

Oxygen

Nutrients

Temperature

Moisture

pH

Light

Algea

Resemble plant cells found on sunlit water and rarely cause human disease

Fungi

Are yeasts and molds, such as tinea pedis, tinea capitis, and tinea cruris

Protozoa

Single celled microscopic microorganisms

Bacteria

Single celled organisms without a nucleus

Spores

A dormant non-reproductive body formed by certain bacteria often in response to a lack of nutrients, and characteristically being highly resistant to heat, desiccation, and destruction by chemicals or enzymes

Pathogenic Bacteria

Bacteria which cause disease

Viruses

Must use the host’s ability to make protein and every, immunization is the most effective means for preventing viral infections

Chain of Infection

Pathogenic microorganism

Reservoir

Portal of exit

Modes of transport

Portal of entry

Host

Communicable Diseases

Diseases that can spread from one person to another

Contagious Diseases

Diseases which are transmitted to many individuals quickly and easily

Epidemic

A large number of people in the same area are infected in a relatively short time

Endemic

A disease or illness regularly found among a particular group of people or within a certain area

Portal of Exit

The path by which a pathogen leaves its host or reservior

Modes of Transmission

The means by which a pathogen moves from the portal of exit to the portal of entry

Types of Modes of Transmission

Direct Transmission

Indirect Transmission

Direct Transmission

Direct contact

Droplet spread

Indirect Transmission

Airborne

Vehicles

Vectors

Portal of entry

Susceptible host

Incubation Period

First phase, from when the pathogen enters the body to the appearance of the first symptoms of illness

Prodromal Period

Second phase, from the onset of initial symptoms such as fatigue or low-grade fever to more severe symptoms

Full Stage of Illness

Third phase, from when symptoms are acute and specific to the type of infection such as lesions covering the body or high fever

Convalescent Stage

Final phase, from when acute symptoms of the infection subsides and the person recovers

Virulence

Pathogen’s strength to cause disease

Nosocomial Infections

Infections that patients acquire while in a health care facility

Dirty

A term for any object or person that has not been cleaned or sterilized for removal of microorganisms

Contaminated

Object was clean or sterile before it touched a dirty object

Clean

Implies that many or most harmful microorganisms have been removed

Sterile

Means that the item is free of all microorganisms and spores

Disinfectants

Destroy most pathogens but not necessarily their spores

Sterilization

Destroy all microorganisms and spores by the process of exposing articles to heat or to chemical disinfectants long enough to kill all microorganisms and spores such as a pressure steam sterilizer called an autoclave

Medical Asepsis

Practice that minimizes the number of microorganisms or preventing and transmission of microorganisms from one person/source to another

Airborne Precautions

Tiny microorganisms from evaporated droplets remain suspended in the air or are carried on dust particles and inhaled

Droplet Precautions

Microorganisms are propelled through the air from an infected person who is sneezing, coughing, talking or being suctioned and deposited on the host’s eyes, nose or mouth

Contact Precautions

Direct contact between a susceptible host’s body surface and an infection or colonized person IS THE MOST FREQUENT MODE OF DISEASE TRANSMISSION

Neutropenic Precautions

Protection from the outside environment, and other people’s microorganisms are kept away from the patient

Surgical Asepsis

No organisms are carried to the patient; microorganisms are destroyed from surface before they can enter the body