SESSION 1- Infection control

pathogen

disease producing organism

virus

may replicate only within a living cell, surrounded by a coat of antigenic protein

bacteria

unicellular microorganism

fungi

mushroom, yeast, mold, etc.

spores that can invade living organisms

sepsis

a condition in which disease producing microorganisms are present

asepsis

a condition in which living, pathogenic microorganisms are absent

- a sterile environment would be ideal but possible

- we must maintain the aseptic technique or chain which includes procedures to avoid contamination and infection

contamination

the presence or microorganisms on a body surface or on inanimate objects or substances

cross-contamination

organisms can spread from patients mouth to us, office personnel or another patient either directly or indirectly

universal precautions

are infection control and safety procedures to protect against bloodborne disease transmission

- assume that all blood, and any body fluid that might be contaminated with blood (such as saliva ), is infectious

standard precautions

expanded the concept of universal precautions beyond exposure to blood and represent a standard of care designed to protect DHCP and patients from pathogens that can be spread by blood, all body fluids, secretions, and extractions (except sweat), non-intcat skin, and mucous membrane

where are standard precautions applied

ALL patient care, in any healthcare setting, regardless of whether a patient has a suspected or confirmed infection

what do standard precautions include

hand hygiene, use of PPE, cleaning and disinfecting environmental surface, safe injection practices and sharps safety, sterilization of instruments and devices, and respiratory hygiene/cough etiquett

what is the chain of infection

infectious agent, reservoirs, port of exit, transmission, port of entry, and susceptible host

what is the infectious agent

a pathogen in sufficient numbers to cause infection: bacteria, viruses, fungi, rickettsia, protozoa or parasite

interventions to break the chain

: clinical identification of lesions and standard precautions

what is a reservoir

a place for the pathogen to reside and multiply

- location: people, blood, body fluids, water, surfaces, equipement, instruments

interventions to break chain

: immunization and standard precautions

what is the portal of exit

a way for pathogens to leave the reservoir and reach a new host

- pathogens can leave the reservoir via the nose, mouth, sneeze, cough, bleed

interventions to break the chain

: standard precautions and waste disposal

What is the mode of transmission?

how the organism is moved from one place to another

- organisms can move to different locations via hands, instruments, etc. this process can be direct or indirect contact transmission

interventions to break the chain

: standard precautions and control of aerosols

what is the portal of entry

an opening allowing the organism to enter the host

- organism can enter host via body orifice, mucous membrane, breaks in skin, or the eyes

interventions to break the chain

: standard precautions and immunizations

what is the susceptible host

a person lacking immunity or physical resistance to overcome invasion by pathogen

examples of a susceptible host include medically compromised patients, immunocompromised patients, and elderly patients

interventions to break the chain

: precautions and treatment of secondary infections

what are the factors that influence the development of infection

- number of organisms and duration of exposure

- virulence of the organisms: their ability to survive interim exposure

- immune status of host: antibody response; defense call reaction

- general physical and nutritional health of host

what are factors that ALTER normal defences

- abnormal physical conditions

EX: defective heart valve

- systemic diseases

EX: leukemia, diabetes, alcoholism, glomerulonephritis, AIDS, etc.

- drug therapy

EX: steroids, immunosuppressant drugs

- prostheses and transplants

EX: joint replacement or organ transplant

what does auto mean

self

what is an autogenous infection

an infection that develops or originates within a person when the normal defense mechanisms are modified

- the individual is the source of the organisms

EX: organisms from the oral cavity are forced into the tissues during dental hygiene instrumentation

what is cross-infection

AKA: cross-contamination

infection that occurs when organisms are transmitted from 1 person to another either direct or indirect transmission

EX of direct transmission: sneezing

EX of indirect transmission: by way of light handles

disease process/etiology of autogenous infection

caused by bacteremia

what is bacteremia

Presence of bacteria in the bloodstream.

- bleeding occurs in the oral cavity, portal of entry to body is provided to organisms

- organisms enter blood stream (bacteremia) and travel to another site and sets up the infection

conditions predisposing to autogenous infections

medically. compromised, immunocompromised and elderly

how do you prevent an autogenous infection

1. lower surface microbial count by oral hygiene measures to remove biofilm

2. enhance the defense mechanism

how do you lower surface microbial count by oral hygiene measures to remove biofilm

use an antimicrobial mouthrinse or antiseptic

- an antiseptic cleans bacteria from skin prior to injuection

- a pre rinse is an antimicrobial mouthrinse, the patient swishes with the rinse for 1 minute before treatment to lower the bacterial count in the mouth

how do you enhance the defense mechanisms

have at risk patients take an antibiotic prior to treatment so when bacteremia occurs the patients immune system is increased by the presence of the antibiotic

what are the 5 ways transmission of microorganisms take place

direct contact, indirect contact, airborne, dust-borne, waterborne

what is direct contact transmission

the transmission of microorganisms from an infected person to person (host) via blood, saliva or other oral secretions

what is indirect contact transmission

the transmission of microorganism through contaminated instruments, operatory equipment or environmental surfaces

- this process takes place via person-to-person transmission by way of an inanimate object

what is airborne infection by oral and respiratory fluids (airborne particles)

aerosol, spatter, origin of aerosol production

what is aerosol

AKA droplet nuclei

artificially generated collection of particles suspended in air and capable of causing an airborne infection

- very small paticles less tha 50 microns can be inhaled into the lungs

what is spatter

heavier, larger particles that remain airborne only a short period of time

- greater than 50 microns in diameter can be seen on glasses, clothing, skin, and hair

- can drop onto objects, people, or the floor (fall within 2 feet of origin

what is origin of aerosol production

produced during all intraoral procedures

EX: air/water spray, hand-piece activity (polishing), and ultrasonic scaling

what are dust-borne organisms

microorganisms can be a single organism or a cluster of organisms that can adhere to dust or debris particle

- found in the air

- could come from outside (tetanus bacillus or clostridium tetani), from airborne particles, or from patients oral cavity

- can be a source of contamination for instruments, hands and equipment as they settle

what is waterborne transmission

transfer of organisms through contaminated dental unit waterlines

- water left in lines creates a biofilm

- significant pathogens are Legionella pneumophila and Pseudomonas aeruginosa

how do you avoid waterborne transmission in water

run water through all tubing for at least 2 minutes at the start of the day and the waterlines need to be flushed for at least 20-30 seconds between each patient during the day

- GHC dental hygiene clinic uses DentaPure system or ICX tablets

- steps 1 and 2 prevent accumulation of odor and foul taste bacteria

REVIEW QUESTION

cross-contamination refers to the spread of microorganisms from one source to another; this may include which of the following

person to person, person to inanimate object, and inanimate object to person

what are the methods to prevent transmission of microorganisms

medical history, pre-procedural oral hygiene measures, clean water, protect clinician, protect patient

true or false: you do not have to take a comprehensive history every time

false

what should you do if patient is in acute phase of infection

postpone treatment

what is the role of medical history in disease prevention

a comprehensive MH (medical history) identifies conditions that make one more susceptible to autogenous infections

- identifies certain pathogens which may be present in the oral cavity

true or false: a negative health history does not mean that the patient is disease or pathogen free. the patient could not be aware or not bbe truthful of the problem

true

true or false: problems arise because patients do not always give or have complete information about their health status, we MUST assume pathogens are always present and practice defensively

true

what are the pre-procedural oral hygiene measures

toothbrushing and using a mouthrinse can reduce the numbers of bacteria contained in the aerosols

what are ways to interrupt transmission

- use rubber dam, high volume evacuation, and manual instrumentation

- employ vacuum cleaning to remove dirt and microorganisms rather than dust arousing housekeeping methods (cleaners will need filters)

- instal air-control methods to supply adequate ventilation, filtration and relative humidity

how do you use clean water to prevent transmission of microorganisms

run the water through all tubing for at least 2 minutes at the start of the day and for 30 seconds after each patient during the way

how is the clinician protected from transmission of microorganisms

wears PPE during patient care, PPE includes a gown, mask, eye protection, and gloves

how is the patient protected from transmission of microorganisms

the patient wears protective eyewear during treatment

what are transmissible pathogens

- HIV

- HAa, HBV, HDV, HEV (viral hepatitis)

- Neisseria Gonorrhea (STI)

- Mycobacterium Tuberculosis (TB)

transmissible pathogens: Herpes simplex virus

type 1 (oral) and 2 (associated with genital but can involve oral and perioral)

transmissible pathogens: herpetic whitlow

herpes infection of fingers

transmissible pathogens: ocular herpes

herpes in the eyes (can be acquired by herpes simplex type 1 or 2)

transmissible pathogens: Varicella-Zoster virus (VZV)

chickenpox and shingles

transmissible pathogens: Rubella (1) and Rubeola (2)

1- (german measles)

2- (measles)

transmissible pathogens: cytomegalovirus (CMV) and Epstein Barr Virus (EBV)

human viruses- they can have a latent infection

- mononucleosis can be caused by an infection with EBV, it is a viral infection causing fever, sore throat, and swollen lymph glands, especially in the neck

true or false: influenza (flu), mumps, pneumonia (viral and bacterial), colds, staphylococcal and streptococcal infcations are transmissible pathogens

tue

transmissible pathogens: SARS-CoV-2

covid

what are the modes of transmission

- inhalation: of droplets and aerosol particles

- deposition: of respiratory droplets and particles on exposed mucous (mouth, nose, eye)

EX: being coughed on

- touching: mucous membranes with hands that have been soiled either directly by the virus or indirectly by touching surfaces with virus on them

bloodborne transmissible pathogens examples

hepatitis b, hepatitis c and HIV

contact transmissible pathogens examples

chickenpox, hepatitis A, herpes simplex, and SARS-CoV-2

droplet transmissible pathogens examples

mumps, rubella, influenza and SARS-CoV-2

airborne transmissible pathogens examples

chickenpox, measles, tuberculosis, SARS-CoV-2