Dental implications for the management in patients with systemic disease - 2 Flashcards
What is hepatitis?
Inflammation of the liver. Caused by:
- Infection, bacterial or viral
- Alcohol abuse
- Drug toxicity
- Trauma
There are types A to E and also herpes viruses (Epstein Barr) are a form of viral hepatitis.
What are the complications of hepatitis?
- Cirrhosis
- Clotting defects
- Hepatocellular carcinoma
- Chronic glomerulonephritis
- Carrier state
- HBV responsible for over 1,000,000 deaths p.a. worldwide
- Over 350,000,000 chronic carriers worldwide. Most prevalent in Western Africa and Indo-China
What is the risk of inoculation of HIV compared to Hep B?
Much higher risk of getting Hep B from a needlestick injury compared to HIV.
What is hepatitis D (delta agent)
*Rides piggyback on HBV as incomplete RNA virus and replicates only in presence of HBV
*Clinically similar to HBV but increased mortality
*HBV vaccination protects against delta agent
What is hepatits C?
- Recognised in 1989
- Accounts for 90% of post transfusion Non-A Non-B Hepatitis
- Parenteral, rarely sexual, vertical transmission
- Salivary transmission has been observed experimentally in animals
- Over 170,000,000 carriers worldwide
How is Hep C diagnosed?
- Detection of Anti-HCV antibody
- Seroconversion may be delayed for several months
- PCR techniques to amplify HCV RNA may be used to diagnose acute infection
- Higher incidence of developing Hepatocellular carcinoma than with HepB
How can Hep C be treated?
-No vaccination
- Interferon alpha can be given but 50-80% of patients regress after stopping treatment within 6 months
- Ribavarin can be given and has been shown to reduce serum levels of HCV RNA
What’s the incidence of Hep B and Hep C?
Hepatitis B:
• Highest prevalence 15-44 years
• Peak incidence 25-34 years
• M:F 1.5:1
Hepatitis C:
• Highest prevalence 25-44 years
• M:F 2:1
What is the risk of HCVseroconversion following a
needlestick with HCV contaminated blood?
Can be as high as 10%
What are prions?
- Proteinaceous Infectious Particles
- <30nm in size
- Not uniformly distributed in tissue
- Resistant to chemical and physical destruction
- Agents causing Transmissible Spongiform Encephalopathies (TSE’s)
What are Transmissible Spongiform Encephalopathies (TSE’s)?
- A group of diseases characterised by spongiform change in the CNS
- First described in sheep 200 years ago (Scrapie)
- More recently described in cattle (BSE)
What are human forms of TSE’s? (Transmissible Spongiform Encephalopathies)
•Kuru
•Sporadic Creutzfeldt Jakob Disease (CJD)
•Familial Creutzfeldt Jakob Disease (CJD)
-Fatal Familial Insomnia
-Gerstmann-Straussler-Scheinker
•Iatrogenic Creutzfeldt Jakob Disease (CJD)
•Variant Creutzfeldt Jakob Disease (vCJD)
What is CJD?
• 3 types recognised:
-Sporadic CJD (Majority of cases 85%)
-Familial CJD (10% of cases)
-Varient CJD (link BSE)
• Any of these may cause iatragenic CJD if transmitted directly (1% cases per year)
What are the clinical features of variant CJD?
• Lower mean age of onset than sporadic (29 vs 60 years)
• Longer duration of illness (14m v 5m)
• Early psychiatric changes, sensory symptoms and
cerebellar signs
What is the transmission of vCJD?
Documented human to human transmission:
• Dural grafts
• Corneal grafts
• Blood products (from infected pool)
• Inadequate sterilisation of surgical instruments
• Human growth hormone & gonadotrophins
• Ritual cannibalism