INFECTION CONTROLUnit #8

Definition Infection Control: Efforts

designed to protect both the patient and care provider.

Infectious Disease: Any illness resulting from invasion of a host by disease producing organisms such as bacteria, viruses, fungi, or parasites.

Microorganisms Also known as: microbes Small living plant/animal not visible

to naked eye Found everywhere in the

environment, including in/on human body

Many microbes exist on or within us and do not cause disease or infection (are called non-pathogens)

Microorganisms Microbes that cause

infection/disease are called pathogens

Some microbes can be beneficial (Normal Flora)in one body system & become pathogenic in another

(ex. E-coli- normal in large intestine, causes UTI in urinary)

Classifications of Microbes5 types:

Bacteria Protozoa Fungi Rickettsiae Viruses

1. Bacteria Simple one-celled organism that

can produce disease in a host, can multiply outside of cells on surfaces or objects.

Classified by shape and arrangement

Bacterium protected by a hard shell is called a spore

3 main types: cocci, bacilli, spirilla

Bacteria-Cocci Round/spherical in shape 3 types:

1. Diplococci-occur in pairs or 2 circles, causes gonorrhea, meningitis, & pneumonia

2. Streptococci-occur in chains, causes strep throat

3. Staphylococci-occur in clusters/groups, causes boils, wound infections & toxic shock, UTI’S

Streptococci Strep bacteria

Staphylococci Staphylococcus aureus

(wound)

Bacteria-Bacilli Rod shaped Occur singly, in pairs, or in chains Many have flagella(threadlike

projections like tails that allow them to move)

Ability to form spores or thick walled capsules(extremely difficult to kill while in spore form)

Can cause TB, tetanus, whooping cough, botulism

Bacillus Anthracis Anthrax with white blood cells

Bacteria-Spirilla Spiral or corkscrew in shape Include corkscrew spirochete Can cause syphilis and cholera

2. Protozoa One celled animals Found in decaying materials &

contaminated water Some are pathogenic & cause

malaria, amebic dysentery, Pneumocystis Carini Pneumonia (PCP), Trichomonas

Protozoa Plasmodium: Malaria

3. Fungi Simple plantlike organisms Live on dead organic matter Yeasts & molds are common

forms of pathogenic fungi Can cause ringworm, athlete’s

feet, & histoplasmosis (systemic respiratory infection)

4. Rickettsiae Parasitic microbe:1. Cannot live outside the cells of

another living organism2. Commonly found on fleas, ticks, &

mites3. Transmitted to humans by bites of

these insects4. Can cause typhus fever & Rocky

Mountain spotted fever

Rickettsiae Rocky Mountain Spotted

Fever

5. Viruses Smallest microbe-only visible with

electron microscope Cannot reproduce unless they are

inside another living cell Spread mainly from human to

human by blood & body secretions Very difficult to kill-resist most

disinfectants, not affected by antibiotics

Can cause common cold, flu, pneumonia, measles, chickenpox, herpes, warts, hepatitis B, HIV

Virus Hepatitis B virus

Factors Required for growth of Microbes

Warm environment Darkness-most are killed quickly in

sunlight Source of food & moisture Need for oxygen varies- aerobic(need

O2 to live) anaerobic(don’t need O2) Human body is ideal supplier of all of

these requirements

Pathogenic Microbes cause Infection/Disease

1. Some produce poisons (toxins) which harm the body

2. Some cause an allergic reaction resulting in watery eyes, runny nose & sneezing

3. Others attack & destroy the living cell they invade ( ex. Malaria invades RBC & causes it to rupture, HIV invades T-cells)

Chain of Infection Factors that must exist for disease

to occur. Includes: 1. Causative agent 2. Reservoir 3. Portal of exit 4. Means of transmission 5. Portal of entry 6. Susceptible host

Causative Agent /

PathogenReservoi

rPortal of

Exit

Host

Transmission

Chain of Infection

Portal of Entry

Chain of Infection1. Causative agent- pathogen such

as bacteria or virus2. Reservoir place- where causative

agent lives. Common reservoirs include human body, animals, environment, and fomites ( objects contaminated with infectious material that contains the pathogens, i.e. pencil, desk, hand rail, etc.)

Chain of Infection A Human being or animal that is a

reservoir for microorganisms but is not ill with infection/disease is a carrier or host. (Example: HIV)

Chain of Infection3. Portal of exit- way for causative

agent to escape from the reservoir. Pathogens can leave the body through urine, feces, saliva, blood, tears, mucous discharge, sexual secretions & draining wounds

Chain of Infection4. Means of transmission- pathogen

must be transmitted to another reservoir or host where it can live.

Five main routes of transmission:1. Contact- direct/indirect2. Droplet- propelled short

distances through air (flu)3. Airborne- remain suspended in

air for long periods of time ( TB, measles, chicken pox)

Chain of Infection Five main routes of transmission:

4. Vectorborne – Insect bite (fleas/ticks)

5. Common Vehicle – pathogen transmitted through items such as surgical instruments, stethoscopes, blood pressure equipment, etc.

Routes of transmission:CONTACT

Contact: According to the CDC, this is the most frequent method of disease transmission in a hospital environment. Direct- direct contact transmission from one person to another through physical contact. Indirect- transmission from one person to another through an object such as contaminated hands or medical instruments (needle stick, dressings, patient care items).

CONTACT PRECAUTIONS Patients under contact precautions

should be placed in a private room or in a room with another patient who has the same infection. If this is not possible, patient placement will depend on the type of infection and an infection control expert should be consulted.

CONTACT PRECAUTIONS Gloves should be worn Change gloves after handling

potentially infective material Dispose of gloves before leaving

room. NEVER wear gloves in hallways or

outside patient’s room

CONTACT PRECAUTIONS A non-sterile gown should be worn

when entering the patient's room if clothing may be contaminated.

Remove before leaving patients room

Avoid touching contaminated areas with uniform/hands

CONTACT PRECAUTIONS Patient movement should be

limited, but if it is necessary, care should be taken not to contaminate other patients and surfaces.

Whenever possible, patient care equipment should be dedicated to a single patient or group of patients with the same infection. If this is not possible, the equipment must be carefully disinfected after each use.

Routes of transmission: DROPLET Droplet transmission - Occurs

when an infected patient expels droplets into the air and the droplets land in the nasal cavity, mouth, or conjunctiva. The droplets are generated from coughing, sneezing, talking, and by some medical procedures. When you sneeze, millions of tiny droplets are propelled from your mouth and nose.

The droplets fly through the air rather than remaining suspended in the air. Measles, mumps, rubella, and Severe Acute Respiratory Syndrome (SARS) can all be transmitted through droplet transmission. Almost all common diseases may be spread through droplet transmission.

Routes of transmission: DROPLET

DROPLET PRECAUTIONS

Placed in a private room Or room with patient who has the

same infection. Three foot separation between the

infected patient and other people It is not necessary to keep the door

closed. Health care personnel should wear

a mask and goggles The patient should wear a mask if

moved

Airborne transmission - when tiny particles containing pathogens remain suspended in the air for long periods of time.

Examples: Measles and chickenpox

Routes of transmission: AIRBORNE

One of the worst outbreaks of disease in human history was the influenza pandemic of 1918. Historians believe it began in America.

At least 21 million people died, and possibly as many as 50 million. Many of them drowned to death when fluid from the infection filled their lungs.

Some airborne pathogens can be spread in the wind, and affect huge areas.

AIRBORNE PRECAUTIONS Placed in a private room or, if

necessary, OR: In a shared room with another

patient who has an active infection of the same type.

Door should be kept closed Air circulation system must prevent

spread of unfiltered air to other areas

Negative Air Pressure System Patient movement around the

facility should be minimized.

AIRBORNE PRECAUTIONS If the patient must be moved, he or

she should wear an N95 mask. Everyone entering the room should

wear a N95 respirator. Examples: pulmonary tuberculosis,

chickenpox,

Vector-borne transmission A vector - organism that carries

pathogens from one host to another.

Examples: fleas, ticks, and rats. Malaria, yellow fever, and bubonic plague are all diseases that can be spread through vectors.

Common vehicle transmission This type of transmission occurs

when pathogens are spread to several hosts through a single contaminated item such as food, water, or surgical instruments.

Example E. coli spread through food.

Chain of Infection5. Portal of entry- way to enter a new

reservoir or host Different portals of entry:

Breaks in the skin or mucous membrane

Respiratory tract Digestive tract Genitourinary tract Circulatory system

Chain of Infection6. Susceptible host- individual who

can contract the disease Most susceptible- elderly,

newborns, persons with weak immune systems, persons with cancer

Humans become host when large numbers of pathogens invade the body and body defenses are weak

Breaking the Chain of Infection If any part of the chain can be

eliminated, the spread of disease/infection will be stopped

Follow practices to interrupt or break this chain (wash your hands)

Aseptic techniques Asepsis- absence of disease

producing microbes or pathogens Common aseptic techniques:

handwashing & good personal hygiene, using disposable gloves when contacting contaminated objects, proper cleaning of instruments & equipment

Handwashing: the single most effective way to prevent the spread of pathogens

Levels of aseptic control1. Antisepsis - prevent/inhibit the

growth of pathogenic organisms. Usually not effective against

spores & viruses Can be used on the skin Example; Alcohol & betadine

Levels of aseptic control2. Disinfection - process that

destroys or kills pathogenic organisms

Used mainly on objects not people

Not always effective against spores & viruses

Can irritate and damage the skin, Example; Bleach solutions

Levels of aseptic control3. Sterilization - process that destroys

all microorganisms both pathogenic and nonpathogenic.

Kills spores & viruses Steam under pressure, gas,

radiation, and chemicals can be used to sterilize objects

Autoclave is the most common piece of equipment used for sterilization

Infection control methods CDC (Center for Disease Control)

has identified 2 levels for infection control.Standard Precautions Transmission-Based Precautions

Goal: Keep pathogens within a specific area

Infection control methods Standard precautions: treat all

patients as though they may be infected.

Standard precautions combine the major features of :

1. Universal Precautions - reduces the risk of transmitting bloodborne pathogens

2. Body-Substance Isolation (BSI)- reduces the risk of transmitting pathogens from moist body substances

Standard Precautions Wash hands:

Before/after examining patients After contact with blood, body fluids &

contaminated items. Wear gloves: if there could be

contact with blood, body fluids, mucous membrane, or broken skin.

Remove gloves: Before going to another patient, wash hands and put on new gloves.

Wear a mask protective eyewear and gown: when splashes or sprays of body fluids are likely.

Standard Precautions Do not recap needles. EVER! Clean and disinfect frequently

touched surfaces including beds, bed rails, patient examination tables and bedside tables

Launder soiled linens and avoid direct contact with soiled items

Use oral rather than injectable medications whenever possible 

Universal Precautions Universal Precautions - introduced

in 1985 as a response to the appearance of AIDS.

Treat all materials as though they are infected with diseases such as HIV or HBV.

Use gloves and gowns, masks and

eye protection during medical procedures.

Infection control methods Standard precautions include:1. Protective work practices -

handwashing, handling sharps, good hygiene

2. Use of personal protective equipment (PPE) - gloves, gowns, face shields, masks

3. Protective housekeeping (disinfectants)

4. Protection: Hepatitis B vaccination

5. Exposure reporting

Infection control methods Transmission-Based Precautions are

used in addition to standard precautions.

Categories include airborne, droplet, contact

Place patient in private room Keep their door closed Wear masks & gloves to enter the

room, Move patient only for essential

purposes Have patient wear mask outside of

the room

So Go Out,SAVE LIVES

and FIGHT DISEASE!!

The END!