Overview Discussion Hepatitis B Definition Epidemiology Clinical course and symptoms Prevention Treatment options
Hepatitis Hepatitis is an injury to liver characterised by presence of inflammatory cells in the liver tissue. It can be self limiting, or It can progress to scarring of the liver. Hepatitis viruses cause most cases of liver damage worldwide
Hepatitis BHBV is a Hepadna virus.An extremely resistant strain capable of withstanding extremetemperatures and humidity.It can survive when stored for 15 years at -20°C, for 24 months at -80°C, for 6 months atroom temperatures, and for 7 days at 44°C.
Hepatitis BThe hepatitis B virus is transmitted throughcontact with the blood and body fluids ofsomeone who is infected. The same way as human immunodeficiencyvirus (HIV).Hepatitis B is nearly 100 times as infectious asHIV.
HEPATITIS B (SERUM HEPATITIS)• Transmitted by:1. Contaminated blood products or article2. Body secretions3. Introduction of infectious material into eye, oral cavity, lacerations or vagina4. Contaminated needles during administration of medications shared by drug users
INCUBATION PERIOD• 24 to 180 days; average 60-90 days
Hep B epidemiology• 1/3 of world’s population has been infected• 350 million with chronic disease• 15-25% of these die due to liver related diseases – 1 million deaths annually
Hepatitis B primary infection• Symptoms – Malaise, fatigue, anorexia, nausea, low grade fever after 45-160 day incubation• Can be asymptomatic – More common in children
Secondary prevention :Diagnosis• A battery of serological tests are used for the diagnosis of acute and chronic hepatitis B infection.• HBsAg - used as a general marker of infection.• HBsAb - used to document recovery and/or immunity to HBV infection.• anti-HBc IgM - marker of acute infection.• anti-HBcIgG - past or chronic infection.• HBeAg - indicates active replication of virus and therefore infectiveness.• Anti-Hbe - virus no longer replicating. However, the patient can still be positive for HBsAg which is made by integrated HBV.• HBV-DNA - indicates active replication of virus, more accurate than HBeAg especially in cases of escape mutants. Used mainly for monitoring response to therapy.
Secondary prevention :Treatment• Interferon - for HBeAg +ve carriers with chronic active hepatitis. Response rate is 30 to 40%. – alpha-interferon 2b (original) – alpha-interferon 2a (newer, claims to be more efficacious and efficient)• Lamivudine - a nucleoside analogue reverse transcriptase inhibitor. Well tolerated, most patients will respond favorably. However, tendency to relapse on cessation of treatment. Another problem is the rapid emergence of drug resistance.• Adefovir – less likely to develop resistance than Lamivudine and may be used to treat Lamivudine resistance HBV. However more expensive and toxic• Entecavir – most powerful antiviral known, similar to Adefovir• Successful response to treatment will result in the disappearance of HBsAg, HBV-DNA, and seroconversion to HBeAg.
Secondary prevention :Treatment• Who to treat – Chronic active hepatitis > 6 months duration – S Ag+, E Ag +/-, DNA+, ALT > 2 x normal – Active hepatitis, advanced fibrosis on biopsy• Goal of treatment – Stop viral replication: HBV DNA becomes Neg – Convert E Ag+ to E Ag--; E Ab becomes pos – Improve histology, prevent progression to cirrhosis – Prevent hepatoma – With successful treatment 1-2% per year will loose S Ag
Prevention• Vaccination - highly effective recombinant vaccines are now available. Vaccine can be given to those who are at increased risk of HBV infection such as health care workers. It is also given routinely to neonates as universal vaccination in many countries.• Hepatitis B Immunoglobulin - HBIG may be used to protect persons who are exposed to hepatitis B. It is particular efficacious within 48 hours of the incident. It may also be given to neonates who are at increased risk of contracting hepatitis B i.e. whose mothers are HBsAg and HBeAg positive.• Other measures - screening of blood donors, blood and body fluid precautions.
Prophylaxis• Hepatitis B immune globulin (HBIG) and vaccine• Indications – Patients with no history of vaccine and • Percutaneous exposure (needle sticks) • Household contacts exposed to blood – Perinatal exposure – prevents transmission in 95% of mothers HBsAg positive when given within 12 hours of birth • Breast feeding ok if baby received prophylaxis
Hepatitis B Prevention• Behavior modification – Eliminate high risk behavior; use condoms – Acute infection has declined for 20 years• Screen pregnant mothers – HBIG and HBV vaccination at birth prevents 95% of perinatal infections• HBV Vaccination – Perinatal exposure – Persons with sexual, mucosal, percutaneous exposures – Persons with HCV or IV drug abuse – Homosexuals – Health care workers – Hemodialysis patients – Universal vaccination for children• Hepatitis B Immune Globulin – Perinatal exposure – Needle stick exposure – Persons with recent sexual, mucosal, percutaneous exposures
Prevention of Perinatal Hepatitis B Virus Infection• Begin treatment within 12 hours of birth• Hepatitis B vaccine (first dose) and HBIG at different sites• Complete vaccination series at 6 months of age• Test for response after completion of at least 3 doses of the HepB series at 9 through 18 months of age (generally at the next well-child visit)
Six Responsibilities of PerinatalHepatitis B Prevention Program Assure identification Assure all exposed of ALL HBsAg infants receive HBIG positive women and and 1st dose of hep. their infants Prevention B vaccine w/in 12 hours of birth of Perinatal Hepatitis B Transmission Assure that all Assure susceptible completion of 3 household and doses of hepatitis sexual contacts B vaccine and post are vaccinated vaccination testing of exposed infants Conduct active surveillance, quality assurance, and outreach to improve program
Prevention Outcome Increase life expectancy Increases quality of life Reduced health care cost
COMPLICATIONS• Liver cancer (cirrhosis)• Liver failure• Acute infection• Anorexia• Hapatocellular carcinoma• death