Infection Control: Unit 1 - Introduction to Infection Control

Infection Control

A set of practices and procedures that prevent or stop the spread of infection in healthcare settings.

Microorganisms

small living bodies that are not visible to the naked eye.

Non-Pathogen Microorganisms

helpful microorganisms that do not cause disease

Pathogen Microorganisms

capable of causing disease in a human host and can challenge the immune system

Types of Microorganisms

There are four types:

• Bacteria

• Parasites

• Fungi

• Viruses

Bacteria

one-celled microorganisms classified by shape.

The three shapes are:

• Cocci - Round

• Bacilli - Rod shaped

• Spirilla - Spiral or cork screw shaped

Spores

preserve genetic material and help bacteria survive harsh environments

Diseases caused by Bacteria

• Food poisoning

• Strep Throat

• Tetanus

• Syphilis

• Cholera

• C. difficile

Parasite

organism that lives on or in an organism of a different species and survives by taking nutrients from the host.

Three types of parasites that cause disease are:

• protozoa

• helminths

• ectoparasites

Fungi

plant like microorganisms found in the air, soil, plants and water. Types of fungi include:

• mushrooms

• yeasts

• molds

Mycoses

diseases caused by fungi which include

• athlete’s foot

• ringworm

• yeast infections

• thrush

Viruses

• smallest type of microorganism.

• causes disease by invading host cells and taking nutrients

Diseases caused by Viruses

• common cold

• chickenpox

• measles

• herpes

• hepatitis

• HIV and AIDS

• Covid-19

Endogenous Infection

caused by a microorganism already present in the human body.

Some examples:

• herpes

• c. diffile

• tuberculosis

Exogenous Infection

caused by a microorganism, or pathogen, entering the body from the outside environment.

Examples of how they enter the body:

• contaminated surface

• healthcare worker

• insect, such as a tick or mosquito

Nosocomial infections or Healthcare-acquired infections (HAIs)

acquired by a person while in a healthcare setting and often transmitted from on patient to another by healthcare workers

Opportunistic Infection

infections that occur when the body’s defenses are weak

Examples include

• Elderly

• Babies

• Patients with AIDS

• Patients with Cancer

Infectious Disease

it results from an invasion of microorganisms. Not all infectious diseases are transmitted from person to person.

Example:

• Lyme Disease

Communicable Disease

an infectious disease that can be transferred from one person to another person

Chain of Infection

The 6 steps to the Chain of Infection are:

1. begins with a pathogen, called the infectious agent or causative agent

2. The infectious agent must find a reservoir or a place for the infectious agent to live and grow can be a human, animal or surface/object

3. pathogen must have a portal of exit to leave the reservoir and can leave through blood, bodily fluids or excrement

4. after the pathogen leaves the reservoir, it must be moved to another reservoir to continue living and growing and is called the mode of transmission

5. the pathogen must have access to a portal of entry, where the pathogen enters the new reservoir

6. if the reservoir has weak defenses it will contract the disease or infection. the new reservoir is called the susceptible host

Modes of Transmission

how the infection or disease can be transmitted

• Direct Transmission

• Indirect Transmission

Direct Transmission

occur in the following ways

• direct contact

• droplet transmission

Direct Contact

type of direct transmission of a disease/infection

includes:

• touching skin-to-skin

• kissing

• sexual intercourse

Infection Examples:

• MRSA

• Mono

• Gonorrhea

Droplet Transmission

occurs when droplets are expelled by an infectious person. droplets are large and do not remain suspended.

Ways droplets can be expelled:

• talking

• coughing

• sneezing

Infection Examples:

• covid-19

• meningitis

• pertussis (whooping cough)

Indirect Transmission

occur in the following ways:

• airborne

• vehicleborne

• vectorborne

Airborne Transmission

occurs when infectious particles remain suspended in the air for long periods and travel through air currents and cause infection when inhaled

Infection examples:

• measles

• tuberculosis

Vehicleborne Transmission

objects that indirectly transmit diseases such as

• food

• water

• blood

• surfaces

Infection examples

• hepatitis A

Vectorborne Transmission

an organism, such as an animal or insect that carry and transmit infectious pathogens.

Examples of vectors

• mosquitos

• fleas

• ticks

Infection examples

• lyme disease

• malaria

• rabies

Respiratory Hygiene

called “cough etiquette” a two step process that can significantly help reduce the spread of infectious agents from on person to another

Step 1: Cover coughs and sneezes

options include

• wear a surgical mask

• cover mouth and nose with a tissue

• cover mouth and nose with your upper sleeve

Step 2: Clean hands

options include

• wash hands with soap and water

• clean hands with an alcohol-based hand cleanser

Asepsis

a condition free of pathogens

two types of asepsis

• medical

• surgical

Medical Asepsis

maintaining a clean environment in order to reduce the number of pathogens.

also known as the clean technique

common medical asepsis practices include

• handwashing

• routine cleaning

• using personal protective equipment, such as gloves and masks

Surgical Asepsis

maintaining a sterile field, which is an environment free from all microorganisms and spores

also known as the sterile technique

Three Levels of Asepsis

• sterilizing

• disinfecting

• cleaning

Sterilization (High-level Asepsis)

highest level of asepsis. surgical asepsis kills all microorganisms including viruses and spores.

sterilization is only used on instruments and equipment

sterilization methods include:

• pressurized steam - preferred method of sterilizing medical and surgical instruments. an autoclave is used in a medical office to kill microorganisms. it does this at temperatures of 250 degrees for 30 minutes

• dry heat - used for materials that may be damaged by moisture and cannot be sterilized using steam. Dry heat uses temperatures of 340 degrees for at least 60 minutes

• chemical solutions - achieved by soaking equipment that is too large for an autoclave or cannot withstand high temperatures, in a carefully prepared solutions for 3-12 hours

Disinfection (Middle-level Asepsis)

middle level of asepsis and can be classified as high level or low level

Before disinfecting, thorough cleaning of all equipment must be done because materials that remain on the surfaces can interfere with the effectiveness of this process

high level disinfection destroys most pathogens, but is not always effective on spores. it is used on semi-critical devices such as endoscopes, ultrasound probes and ventilators

low level disinfection kills most bacteria, some fungi, and some viruses. used for non critical patient care surfaces that come in contact with skin, such as bed rails, call lights and vital sign machines. can help prevent health care acquired infections

Cleaning (Lowest Level Asepsis)

lowest level of asepsis

also called sanitization

removal of visible organic and inorganic material from objects and surfaces

does not destroy viruses or spores

can be used on people, objects and equipment

cleaning product examples:

• soap to wash hands

• alcohol to prepare a patients skin

• antiseptic solutions such as iodine and betadine

Hand Hygiene

most basic type of medical asepsis

hands can act as a mode of transmission in the chain of infection by carrying pathogens from one patient to another

When hands need to be cleaned:

• when arriving at a health care facility and immediately before leaving

• before/after patient contact

• before/after performing a procedure

• before/after handling a specimen

• before/after touching the mouth, eyes or nose

• before donning gloves and after removing gloves

• after contacting soiled or contaminated items

• after picking anything up off the floor

• after using the bathroom

• after coughing, sneezing or using a tissue

Procedures for Hand Cleansing (Two Methods)

hand washing - involves using plain soap and water

Steps to handwashing

1. dispense a paper towel and use it to turn on the faucet

2. test the temperature of water with hand and allow it to reach a warm temperature. dispose of the paper towel

3. point your fingers downward and wet yours hands and wrists

4. dispense liquid soap into your hands and work the soap into a lather

5. lather all surfaces for at least 20 seconds. rub firmly as friction gets rid of pathogens on your hands

6. clean your fingernails with a nail brush or rub fingernails again the palm of the opposite hand

7. rinse your hands and wrist with fingers pointed downward

8. use a clean paper towel to dry hands

9. use a clean towel to turn off the faucet

Alcohol based rub - used when soap and water are not readily available

1. dispense the appropriate amount in your hand

2. rub your hands together covering all surfaces

Cleaning Equipment

lowest level of medical asepsis

to clean equipment:

• use soap, water and scrub brushes

• ultrasonic cleaning units - uses sound waves and a cleaning solution to clean dirt and residue. is not effective against viruses or spores. often followed by disinfection or sterilization

Procedures for Cleaning Equipment

Steps

1. clean hands and put on gloves

2. rinse equipment in cool water

3. soak the equipment in warm, soapy water for about 20 minutes

4. use a cleaning brush to scrub equipment

5. rinse the equipment in warm water and make sure soap or residue is gone

6. dry the equipment with paper town and store