Module 3

PPE

-Barriers important to prevent exposure to
microorganisms

-protects clinician’s skin and mucous membranes of eyes,nose and mouth from workplace illness and injuries
○ Gloves
○ Masks, Face shields
○ Protective eyewear, gowns
○ Protective clothing

Small Cuts and Abrasions

Serve as routes of entry
of microorganisms into the body, causing a skin
infection or other more widespread diseases

Gloves

-Protects patient from microbes present on hand of clinician

-Protects clinician from microbes present in oral cavity of patient

When should gloves be changed?

Between patients, torn or punctured

When should utility gloves be worn?

When processing instruments and working with chemicals

-Reusable, not used directly on patient, can be autoclaved, avoid sharing 

-FDA does NOT regulate 

Microbiology

• study of algae, bacteria, fungi, prions, protists, protozoa, and viruses

Pathogenic

-disease causing

-grow best at 98.6 f, moist and dark enviorments

Non-pathogentic

non-disease causing

• can be harmless and beneficial 

Virulence

degree of pathogenicity

• How strong microorganism is 

• determines infectiousness

5 major groups of microorganisms

• bacteria

• virus

• fungi

• protozoa

• algae

3 factors that determine infectiousness

1) virulence of microbe

2) resistance to host

3) dose of available microbe

Opportunistic infection

• pathogen that will take advantage of opportunity

• weakened immune system, altered microbiota or breached integumentary barriers

  • ex) candidiasis, coccidioidomycosis and herpes

Acute infection

rapid onset followed by brief period of symptoms resolve within days

• severity not considered

Chronic infection

• disease that is persistent or otherwise long-lasting in its effects.

  • chronic- disease last more than 3 months

Latent disease

hidden, dormat, inactive condition

• can become active if triggered (ex. stress)

example of latent disease

-chicken pox can be latent after initial attack is over but can become reactivated and turn into shingles

-HIV can remain in t cells

-Latent tuberculosis infection

Bacteria

• simplest alive creatures

• lack nucleus (prokaryotes)

• body host harmless bacteria in respiratory tract, skin, GI

Bacteria shapes

cocci (sphere)

bacilli (rod)

spirochetes (spiral) - can move

Gram staining

• Gram-positive: purple, weaker 

• Gram-negative: pink, harder to eliminate

Oxygen requirements for bacteria

Aerobes: need oxygen

Anaerobes: NO oxygen, will die

Faculuative anaerobes: can survive with or without 

Spores

• most resistant form that protects bacteria when conditions turn unfavorable

  • Inactive and cannot cause disease but bacteria can activate when environment is favorable 

Staphylococcus aureus

causes MRSA

Mycobacterium tuberculosis

causes tuberculosis.

Treponema pallidum

causes Syphilis.

Viruses

• nonliving organism

• smaller than bacteria

• require living host, inject RNA or DNA to reporudce

  • plant, bacteria, animal, human

Can viruses be dormant for a long period?

Yes, ex. HIV patients

Hepatitis that are NOT bloodborne?

• Hepatitis A

• Hepatitis E

Hepatitis A

• caused by hepatitive A virus (HAV)

• spread through fecal-oral route

• vaccine avaliable

Hepatitis B

• caused by hepatitis B virus (HBV)

• spread through direct contact with blood, semen or bodily fluids

  • direct or indirect

• found in salivia but cannot be spread through kissing/shared utensiles

• vaccine mandatory for healthcare professionals

• causes serious damage to liver long damage

How long does HBV survive in dried blood?

7 days

Hepatitis C

• caused by the hepatitis C virus (HCV).

• Spreads through direct contact with blood.

• No vaccine available.

• most common bloodborne infection in us

hepatitis D

• caused by the hepatitis D virus (HDV).

• "Spreads through direct contact with blood.

• Piggy-back condition of the hepatitis B virus.

  • coi-nfection

Hepatitis E

• caused by the hepatitis E virus (HEV).

• Spreads through the fecal-oral route.

Herpes virus

• Herpes simplex virus (HS) type 1: causes oral lesions (primary herpes and herpes labialis).

• Herpes simplex virus (HS) type 2: causes genital lesions.

• Herpes zoster virus (HZV): causes herpes zoster, shingles, and chickenpox.

• Epstein-Barr virus (EBV): causes mononucleosis.

  • kissing virus

HIV

causes AIDS

• spreads through blood and sexual contact with infected person

• human immunodeficient virus (attack t cells)

Hepatitis 

• inflammation of the liver

• symptom= jaundince 

AIDS

oral maifestations

• oral lesions

Types of lesions

Fungal- candidiasis

viral- herpes

bacteria- peridontal

non-hodgkin lumphoma- cancerous

Fungi

• mushrooms, molds, yeast

• eukaryotic 

• in very large numbers- soil, air, 

• reproduce by forming large amount of spores

Candidiasis

• caused by yeast candida present in gential tract, GI tract and skin

• opportunistic infection

• causes oral candidiasis

oral candidiasis

• caused by the yeast Candida albicans.

• Generally appears as a white cluster in the oral cavity.

prion

• Small protein-aceous infectious particle.

• Composed entirely of proteins that lack nuclei acids (DNA, RNA).

• Convert normal proteins into ones with different shapes.

• Different and new category 

  • example:

    • MAD cow disease

    • Creutzfeldt-Jacob disease: rare central nervous system disease causing dementia.

Creutzfeldt-Jacob disease

• caused by prions

• rare central nervous system disease causing dementia.

Chain of infection

1) infectious agents

2) reserviours 

3) portal of exit

4) mode of transmission

5) portal of entry 

6) susceptible host

reservoir

• habitat in which the agent normally lives, grows, and multiplies.

  • Can be a human, water, an animal, or the environment

portal of exit

• exit: path by which a pathogen leaves its host (previous home).

  • blood, secretions, excretions, skin

Mode of transmission 

• method of transportation the pathogen uses to arrive at the "new home."

• includes direct and indirect contact

• ex. airborne, droplets, physical contact

Direct contact

• microorganisms are transferred from one infected person to another without a contaminated intermediate object or person.

• Blood and blood-containing body fluids directly contact the blood, mucousmembrane or non-intact skin (from cuts, abrasions, etc.) of another person.

indirect contact

microorganisms are transferred from an infectious agent through a contaminated intermediate (object, person, suspended air particles, vehicles, or vectors).

portal of entry

the "entrance" the pathogen uses to get inside the "new home" (new host),

• ex) mucous membrane, respiratory system, digestive system, broken skin

susceptible host

• Susceptibility of a host depends on genetics, immunity, and other factors.

• Immunocompromised patients are more susceptible to diseases.

  • ex) diabetes, burns, surgery, age, immune deficiency

Vaccines

provides antibodies to a disease and protects an individual(host).

Infectious agents 

• microorganisms capable of causing disease or illness

• bacteria, fungi, parasites, prions

Breaking chain of infection

If one of the components are absent or broken, the infection is stopped

• ex) clinician gloves prevent contact with mucous membranes and blood, which therefore protects the port of entry.

What disases are caused by direct contact?

infectious mononucleosis

herpes simple virus

HIV 

hepatitis

Airborne tranmission

microorganisms spread through droplets of moisture.

• Infectious pathogens travel directly from the respiratory tract of the infectious individual to the susceptible mucosal surfaces of the recipient.
  Generated by coughs or sneezes, or a fine mist of water.

Droplets (spatter0

• heavy particles that remain airborne for a relatively short period.

What can be transmitted through droplets

• influenza virus

• group A streptococcus 

Aerosols

• tiny particles that remain suspended in the air for a longer period.
  - Power scalers produce aerosol spray.

What can be trasmitted by airborne transmission

• Mycobacterium tuberculosis, rubeola virus (measles), and varicella-zoster virus (chickenpox)

Blood-borne transmission

microorganisms spread through blood and other body fluids.

• The most common examples are HIV, hepatitis C, and hepatitis B.

• Can occur with direct or indirect contact.

OSHA

• organization that provides rules for the protection of employees in the workplace against occupational exposure to blood-borne pathogens.

Food and water transmission

microbes spread through contaminated food or water

• improper food storage, contaminated water, fecal material

Fecal-oral transmission

microbes spread from human or animal stool to mouth 

innate immunity

• Non-specific defense mechanism

• Present at birth and does not need to be acquired through exposure to an invader.

• Naturally active acquired immunity

patient becomes infected, and the body naturally produces antibodies against the antigens.

• e.g., contracting the seasonal flu and becoming immune to it.

artificially active acquired immunity 

• vaccination of an antigen in a safe form that helps the body to produce antibodies against it.

  • e.g., mumps, measles, rubella (MMR), and flu vaccine.

naturally passive acquired immunity 

• antibodies produced by one individual are passed on to another individual.

  • e.g., Rh antibodies from a mother to the baby.

artifically passive acquired immunity

injection of antibodies

• Hepatitis B immunoglobin infection after exposure

recommended immunization for healthcare professionals

• Hepatitis B (mandatory)

• Influenza

• Mumps

• Measles

• Rubella

• Varicella-zoster

Gowns

prevents contamination of street clothing and protects the clinician's skin from exposure to blood and body substances.

• should NOT be taken home

• water resistant 

Masks

• Protect the healthcare professional from inhaling microorganisms spread by the airborne route and accidental splashes.

protective eyewear

Shields the clinician's eyes from spatter or debris generated during procedures.

What is the most important measure to prevent spread of pathogens

effective hand washing

what concentration should alcohol based hand rubs have ? 

60-95%

Transient flora

• colonizes on superficial layers of the skin and can be removed by hand washing

  • acquired during patient contact and contaminated surfaces 

resident flora

• attaches to deeper layer of skin and more resistant to removal 

  • less likely to be associated to infections 

Immunizations

protect both patient and health care professional

required vaccines for health care 

• Hepatitis B

• influenza

• varicella

• measles

• mumps

• polio

• rubella

• tetanus vaccinations

• tuberculin skin test

True/False: vaccines exists for HIV

FALSE

Antimicrobial mouth rinses

reduce number of microorganisms patient might release in form of aerosol or spatter 

Should you let your patient put their lips around the saliva ejector? 

NO, backflow may occur and can cause contamination

What is the major cause of disease transmission to health care professional 

needle-stick injuries 

what method should be used for needles

scoop technique

• NEVER 2 handed technequies

Regulated waste 

• Also called biohazard waste.

• Includes sharps: needles, blades, broken glass, burs, endodontic files, and reamers.

• Blood, blood-soaked items, tissue, and pathologic waste.

• Gauze with little blood is considered household waste, not regulated waste.

• Use a single leak-resistant biohazard bag with a biohazard label.

Non regulated waste

• Most waste in dental offices can be disposed of with ordinary waste.

• includes contaminated waste that contacted blood and body fluids.

• e.g., bibs, barrier, PPE, and items not saturated with blood or saliva.

Where should extracted teeth be thrown away?

medical waste container

• can be potentially infectious material

Where should amalgam be disposed?

recycled amalgam waste separately according to state and local

Where are sharps disposed

• in puncture-resistant, closable, leakproof, biohazard bag.

• Include orthodontic wires, scalpel blades, broken glass, and needles.

Who regulates waste?

EPA and local agency

What can waterline be colonized with?

Microorganisms including bacteria, fungi, and protozoa

How long should DUWL be ran for between patient and beginning of day

Between patient: 30 secs

Beginning of day: 2 minutes

How can bacterial contamination of water be reduced?

• disposable in-line micro filtration cartilage- inserted close to handpiece/air-water

• chemical agents

Can disposable in-line micro filtration cartilages and chemical agents remove biofilms from DUWL?

NO only decontaminate the water

When should public water systems be avoided?

During boil-water advisory

CFU

colony forming units

How many CFU should normal community water contain?

less than 500 cfu/ml

Clinical surfaces 

• Does not touch patient directly and has limited risk of disease transmission.

  • ex) light switches, pens, handles, coountertops

• Clean with low intermediate level disinfectant after each patient 

Housekeeping surfaces

• Does not touch patient directly and has limited risk of
  disease transmission.'

  • ex) floors, sinks

• can be decontaminated with detergent and water only 

When should PPE be on during radiographs?

if blood and other bodily fluids are likely to contact clinician