Viral Hepatitis - PDF

1 Viral Hepatitis 2 Viral hepatitis Viral infection of liver Hepatitis viruses A, B, C, D, E Most relevant ones to dentistry are Hep A, B, C. 3 Hepatitis A Caused by the hepatitis A virus Faeco-oral route. Caught by consuming food and drink contaminated...

1 Viral Hepatitis 2 Viral hepatitis Viral infection of liver Hepatitis viruses A, B, C, D, E Most relevant ones to dentistry are Hep A, B, C. 3 Hepatitis A Caused by the hepatitis A virus Faeco-oral route. Caught by consuming food and drink contaminated with the faeces of an infected person Most common in countries where sanitation is poor. Symptoms pass usually within a few months No specific treatment for it, other than to relieve symptoms like pain, nausea and itching. Prevented by vaccination before travel to high risk countries. 4 Hepatitis B Caused by the hepatitis B virus Common infection worldwide Spread in the blood of an infected person. Spread from infected pregnant women to their babies Can be spread through unprotected sex, sharing needles in drug use, needlestick injuries, sharing razors/toothbrushes 5% become chronic carriers Some develop cirrhosis and liver cancer 5 Hepatitis B In children it can persist for years and cause significant liver damage 90% infected babies develop chronic hepatitis Vaccination for all healthcare workers Since 2017 added to child immunisation list Concentration of hepatitis B virus in body fluids  Low/not detectable: High: Urine Blood Faeces Serum Sweat Tears Wound exudates Breast milk Moderate: Semen Vaginal fluid Saliva Transmission continued…..  Very infectious - more easily spread than HIV  Can live outside the human body for up to 7 days Click to add text  People with chronic hepatitis B can have very large amounts of the virus in their blood  Not spread by hugging, kissing, sneezing, coughing or sharing eating utensils  After needlestick injury, seroconversion risk is 1 in 3 if not vaccinated, compared to 1 in 300 for HIV Pathogenesis  Incubation – 45 to 180 days (average = 60 days)  Virus enters hepatocytes via blood  Immune response to viral antigens expressed on hepatocyte cell surface is responsible for clinical syndrome  5% become chronic carriers (have a higher risk of hepatocellular carcinoma)  Hepatitis B surface antibody probably confers lifelong immunity 9 Symptoms of Hepatitis B 10 Symptoms of Hepatitis B May be asymptomatic. If symptoms develop, they tend to happen 2 or 3 months after exposure to the hepatitis B virus. Flu-like symptoms, including tiredness, a fever, and general aches and pains, loss of appetite, nausea, diarrhoea, gastric pain, Jaundice. Symptoms will usually pass within 1 to 3 months (acute hepatitis B), although occasionally the infection can last for 6 months or more (chronic hepatitis B). Diagnosis  Blood testing – serological tests.  Hep B antigens used as a general marker of infection Hep B antibodies - used to document recovery and/or immunity to HBV infection Virus persists at low levels even after recovery Reactivation can occur spontaneously, particularly if immune system depressed 12 Treatment for Hepatitis B Emergency treatment following exposure to Hep B Dose of Hep B vaccination Dose of immunoglobulin Acute Hepatitis B Rest, analgesia, symptom-relief e.g. metoclopromide for nausea Chronic Hepatitis B Peginterferon alfa-2a stimulates the immune system to attack the hep B virus, given by weekly injection, flu-like side effects Anti-viral medication e.g. tenofovir or entecavir, side effects nausea, vomiting, dizziness 13 Treatment for Hepatitis B contin/ avoid unprotected sex partners should be vaccinated against hepatitis B avoid sharing needles avoid sharing toothbrushes or razors eat a healthy balanced diet avoid drinking alcohol Prevention  Vaccination – for those at increased risk of HBV infection  3 doses: month 0, 1, 6  Immune response: 50% after 1 dose, 95% after 3 doses  Duration of protection: >15 years, dependent on initial antibody response PREVENTION ( CONT'D) Hepatitis B immunoglobulin To protect people exposed to Hep B.....most effective within 48hrs of contact. Other: Screening of blood donors, blood and body fluids precautions Remember!  Hepatitis B carries a definite mortality risk  As health care professionals you are potentially at risk and should be immunised  All patients should be treated as potential carriers of the disease - universal precautions  Always wear your PPE – saliva to eye is a potential route of infection as well as the more obvious  Always avoid the chance of needlestick injury, and always report them if they do happen 17 Hepatitis C Single-stranded RNA virus Pathogenesis, symptoms and routes of transmission same as Hep B Occupational transmission – needlestick injury case reports of transmission from blood splash to eye. UNIVERSAL PRECAUTIONS!! No vaccine against Hep C Long term complications are cirrhosis, liver failure, liver cancer Chronic hep C is treated with direct acting anti-viral medication for 8-12 weeks e.g. ribavarin, simeprevir, sofosbuvir, sometimes combinations of drugs. Side effects include nausea and insomnia Lifestyle changes – stop alcohol, healthy diet, more exercise, stop smoking, don’t share razors and toothbrushes, don’t share needles 18 Hepatitis D and E Hepatitis D is a delta virus Only infects people who already have Hep B Chronic infections cause liver scarring, cirrhosis and cancer Spread with contact with bodily fluids Seen mainly in IV drug users Vaccine available Hepatitis E is an RNA virus Transmitted by faeco-oral route Similar to Hep A No vaccine