37. DMD Occupational Health

Lecture Aims

• Describe the infectious risks facing dental practitioners

• Employment requirements for practicing dentists related to blood borne viruses

• Occupational health aspects of HBV, HCV & HIV

• Post-exposure follow-up measures needed after sharps injury

• Compliance with occupational health arrangements for dental practitioners in Northern Ireland

Infectious Hazards in Dentistry

• Dental professionals face several occupational hazards, including:

  • Needles and other sharp objects

  • Spatter and splashes entering the eyes, nose, mouth & mucous membranes

  • Aerosols

  • Respiratory and contact spread

Minimising Risks Through Occupational Health

1. Pre-employment Immunisation

2. Post-exposure Investigation, Advice & Management

3. Health Clearance

   • Prevents risk from infected dentists to patients

Dental Practice Risks

• Intra-oral, needle stick & sharps injuries can occur due to:

  • most treatment classify as EPP

  • Patient movement or unexpected mouth closure

  • Poor visibility during procedures

  • Most sharps injuries happen during:

    • Resheathing, dismantling, or disposal of needles

    • Clearing instruments

    • Manual instrument cleaning

• Dentists can acquire infections from patients, such as:

  • Influenza, B19, TB

• Importance of practicing contact and droplet precautions

• Keeping vaccinations up to date is crucial

Pre-employment Occupational Health Measures

• Pre-employment Health Assessment

  • Mandatory for new staff

  • Review immunization needs due to high risk of infection exposures

• Immunisation Requirements

  • up to date Routine vaccinations: Tetanus, diphtheria, polio, MMR

  • Selected vaccines: BCG for TB, Hepatitis B, Varicella, Influenza

Post-exposure Investigation & Management

• Determining:

  • Nature and timing of exposure

  • Infectious period at the time of exposure

  • Dentist's risk of severe illness

  • Immunization status of the heathcare worker

  • Availability of post exposure prophylaxis

Example 1: Dental Treatment & TB

• Patients with TB symptoms should be assessed; treatment should be deferred until declared non-infectious by a physician

  • Symptoms include:

    • Persistent cough, blood in sputum, night sweats, fever, weakness, fatigue, weight loss

  • Latent TB is non-infectious

  • Occupational health recommendations include baseline and follow-up tuberculin skin tests for staff

Example 2: Dental Treatment & B19

Parvovirus B19 Symptoms - not in ppt

• Children: Flu-like illness → "Slapped cheek" rash → Lacy body rash

• Adults: Joint pain, mild flu-like symptoms, less rash

• Pregnant Women: Risk of fetal complications (anemia, hydrops fetalis)

• Immunocompromised: Persistent anemia, no rash

• Blood Disorders (e.g., Sickle Cell): Severe anemia (aplastic crisis)

Spread: Respiratory droplets, blood, mother-to-fetus.
Prevention: No vaccine; handwashing helps.

Post-exposure Follow-Up

• Referral to GP for follow-up immunity testing

• Possible exclusion from work during infectious periods

Example 3 - Needle stick injury

• High-risk sources include:

  • Intravenous drug users

  • Sex workers

  • Individuals from sub-Saharan Africa

  • if the source is a child, they have a high risk if mum has HIV

  • unprotected sex with above high risk

  • if the source patient is unknown, usual approach is to assume a low risk exposure

BBVs - Occupational Infection Routes for Healthcare Workers (HCWs) - Parenteral

• Percutaneous Routes: Sharp objects penetrate the skin

• Mucocutaneous Routes: Contamination of nose, eyes, broken skin, or mouth

• Increased risk factors:

  • Deep injury

  • Visible blood on the device used

  • Injury from a needle entering a blood vessel of the source

  • Source has terminal HIV-related illness

Immediate Management of Sharps/Needlestick Injury

1. Immediate first aid:

   • Encourage bleeding, clean under water, dress the wound

2. Seek urgent medical advice (Occupational Health/A&E)

3. Record in the accident book

4. Assess injury for BBV transmission risk

5. Request source patient blood if consent given and test for BBVs

6. Actions for Dentist/Recipient:

   • Baseline blood sample for storage

   • Check Hepatitis B immunity

   • Vaccination and immunoglobulin for Hepatitis B as required

   • Initiate HIV post-exposure prophylaxis (antiretrovirals drug)HAART

   • Hepatitis C early follow up testing for RNA at 6 and 12 weeks

     - Follow up Hepatitis C serology at 12 and 24 weeks

Post-exposure Prophylaxis (PEP) & Testing for High-Risk Injury

• HIV:

  • No vaccine; Only for high risk - initiate antiretroviral drugs ASAP within 24-72 hours, Truvada AND Rategravir for 28 days

  • but not 100% effective, less effective if delay start

  • HIV antibody test 12 weeks after PEP

• HBV:

  • Vaccine available; accelerated vaccination for non-immune individuals. Booster available if ongoing risk of exposure

  • If not immune AND known positive HBsAg —> given Hep B immunoglobin

  • HbsAg checked at 24 weeks (6months)

• HCV:

  • No vaccine; no specific PEP,

    Hepatitis C early follow up testing for RNA at 6 and 12 weeks

    Follow up Hepatitis C serology at 12 and 24 weeks

Health Clearance Overview

• UKHSA Guidance: Integrated guidance on health clearance for healthcare workers living with BBV

• Health clearance protects patients from exposure to HBV, HCV, & HIV

  • Hepatitis B vaccination is offered along with necessary tests

Non-Exposure Prone Procedures (Non-EPPs)

• Non-Exposure Prone Procedures (Non-EPPs)

  • 1. Procedures where hands and fingertips are visible and outside the body at all times.

  • Involves internal examinations or procedures 2. without risk of injury to gloved hands, 3. adhering to routine infection control.

Examples:

• Intravenous sedation

• Minor surface suturing

• Incision of external abscesses

• Teeth bleaching

Categories of Exposure Prone Procedures (EPPs)

• Category 1: 1. Hands visible and outside the body most of the time. 2. but slight risk of injury to gloved hands. Examples include local anaesthetic injections, teeth polishing

• Category 2: Hands may not be visible at all time; BUT unlikely to injure gloved hands from sharp instument or open tissue. If injury → can immediately notice

• . Example: routine tooth extraction, periodontal and implant surgery

• Category 3: fingertips are out of sight during procedure. Significant risk of injury to hands. → patients open tissue expose to HCW blood and is unnoticed.

• No example

how to ensure samples are from the HCW

take sample in the OH service and transport by OH to lab

show identification

standard health clearence for NEW HCW and students

Check HbsAg

Hep B vaccine (with recombonant DNA inactvated), check vaccne response - antibpdy level > 100 mIU/ml → immune

no response - reuquire immunoglobulin

pre test discussion → test Hep C antibodies → negative - never infected. positive → test Hep C RNA

pre test discussion → HIV serology test(4th generation)

Specific Health Clearances for HCWs Performing Exposure Prone Procedures (EPPs)

• Additional health clearance needed for individuals performing EPPs

• HCW who DO NOT perform EPPs do not require ongoing OH supervision

• HCW have Right to decline BBV testing, but they will not be allowed to perform exposure-prone procedures, since there's no confirmation they are BBV-negative.

• Tests for:

  • Hepatitis B surface antigen HbsAg

  • Hepatitis C antibody

  • HIV antibody

• all negative to do EPP

Requirements if infected to preform EPP

• HCV Infected DEntist: Testing for Hepatitis C RNA by PCR, CANNOT preform EPPs if positive.

• Can do EPP when 1. negative 3months after treatmet and 2. negative after anotehr 3 months

• HBV Infected Dentists: test Hep B DNA by PCR, can do EPP if HBV DNA is less than 200 IU/ml, and on oral antiviral therapy, test every 6 months

• HIV Positive Dentists