Disease Transmission In Dentistry

By DR. Shahzadi Tayyaba Hashmi

DNT 231

Disease Transmission

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

Chain of infection

Chain of InfectionThe 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 Infection1. Virulence: The virulence of an organism is its

strength or ability to cause disease The more virulent the organism, the

more serious the disease2. 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

Modes of disease transmission

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 Transmission2) Indirect Transmission3) Airborne Transmission4) Aerosol, spray or splatter transmission5) 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

Disease transmission in the dental office

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 anotherTherefore, it is possible for the dental

healthcare worker to transmit microorganisms to the patient unintentionally

It is important to use fresh PPE for each patientThis includes a new pair of disposable gloves, a

new disposable mask, a clean and disinfected safety glassesHand 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 teamThe 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

Cross contamination in dental office

Cross contamination in dental office

Thank you