Disease Transmission In Dentistry

Dr. Shahzadi Tayyaba Hashmi

shahzadi@inaya.edu.sa

• Germs are the main cause of disease• Germs are also termed as microorganisms or

pathogens• When these germs multiply, they become

diseases . Diseases can be transmitted only in a distinct pathway. This pathway is known as chain of infection

DISEASE TRANSMISSION

Chain of infection

• The chain of infection contains four links:i. Virulenceii. Number of microorganismsiii. Susceptible hostiv. Portal of entry• All of these must be present for the individual to become

infected with a disease. If one of these is missing, the disease cannot be transmitted

CHAIN OF INFECTION

1. Virulence:• The virulence of an organism is its strength or ability to

cause disease• The more virulent the organism, the more serious the

disease

2. Number of microorganisms:• The number of microorganisms describes the amount

of pathogens present.• A large number of pathogens will destroy the body

immune system and diminish the body’s ability to fight off the pathogens

CHAIN OF INFECTION

3. Susceptible Host:• A susceptible host is someone who has a compromised

immune system. This means that this person has a disease already, is currently undergoing treatment for a condition, has not been getting enough rest or under stress

• These things can suppress a person’s immune system and cause her or him to be more susceptible to an illness or disease

4. Portal of entry:• A portal of entry is the way in which an infection enters the

body

CHAIN OF INFECTION

• An infectious disease is one that is contagious and can be transmitted from host to host via the chain of infection

• Diseases are transmitted in one of the following five modes of transmission:

1) Direct Transmission

2) Indirect Transmission

3) Airborne Transmission

4) Aerosol, spray or splatter transmission

5) Blood-Borne transmission

MODES OF DISEASE TRANSMISSION

1. Direct transmission:• Direct contact with infected blood, saliva or other potentially infectious

materials• Personal protective equipment (PPE) is essential in preventing transmission

2. Indirect transmission:• This route of transmission occurs when the dental healthcare professional

comes in contact with a contaminated surface without the protection of PPE

3. Airborne transmission:• Occurs through modes of inhalation• For example, a patient sneezes, and another inhales some spores that may be

present in the sneeze• Many serious diseases spread via air

MODES OF DISEASE TRANSMISSION

4. Aerosol, Spray or Splatter:• This route of transmission is a form of airborne transmission• Aerosol is generated by the use of the high-speed hand piece in the

mouth• An aerosol mist is emitted from the oral cavity, which is contaminated

with patient’s bacteria• Spray and splatter follow the same form and occurs in patient’s mouth

contaminating the surrounding area

5. Blood-Borne transmission:• Occurs only from blood-to-blood contact with an infected individual• Many diseases such as HIV/AIDS and hepatitis B, are transmitted in

this way• The most common transmission is through needle-stick injury

MODES OF DISEASE TRANSMISSION

• All members of the dental healthcare team should be concerned about disease transmission in the dental office

• Dental professionals call this cross-contamination• Cross-contamination refers to germs within or from

dental setting being transmitted to other areas of the dental office or carried out of the dental sitting

• This can occur in a number of ways , including patient to patient, healthcare worker to patient, patient to healthcare worker and healthcare worker to community

DISEASE TRANSMISSION IN THE DENTAL OFFICE

1. Patient to patient:

• Cross contamination can occur from patient to patient by not changing PPE between patients, by not properly disinfecting the treatment room, and by not properly sterilizing the dental instruments

• The germs and bacteria are then introduced into a new host causing a “crossing” of infection

DISEASE TRANSMISSION IN THE DENTAL OFFICE

2. Healthcare worker to patient:• The patient and dental healthcare worker sit in a very close

proximity to one another• Therefore, it is possible for the dental healthcare worker to

transmit microorganisms to the patient unintentionally• It is important to use fresh PPE for each patient• This includes a new pair of disposable gloves, a new

disposable mask, a clean and

disinfected safety glasses• Hand washing is always an

important aspect of infection control

DISEASE TRANSMISSION IN THE DENTAL OFFICE

3. Patient to health care worker:• Patient can also transmit microorganisms to the dental

healthcare team• The same precautions as above should be followed by the dental

healthcare team to prevent the transmission of microorganisms

4. Healthcare worker to community:• The dental healthcare worker may unintentionally transmit

contaminants from dental office into the community• Care should be taken by the dental healthcare worker to avoid

this by changing and laundering contaminated clothes properly prior leaving to dental office

DISEASE TRANSMISSION IN THE DENTAL OFFICE

Cross contamination in dental office

Cross contamination in dental office

Thank you