HBV

• Viral hepatitis


  A term commonly used for several diseases that are clinically similar but etiologically and epidemiologically distinct
• Hepatitis A


  Formerly called "infectious hepatitis"
• Hepatitis B


  Formerly called "serum hepatitis"
• Hepatitis D


  Also known as Delta hepatitis, is an infection dependent on the hepatitis B virus (HBV)
• Epidemic jaundice was described by Hippocrates


  5th century BCE
• First recorded cases of serum hepatitis following the administration of smallpox vaccine containing human lymph to shipyard workers in Germany


  1883
• In the early and middle parts of the 20th century, serum hepatitis was repeatedly observed following the use of contaminated needles and syringes
• In 1943, Paul Beeson described jaundice that had occurred in seven recipients of blood transfusions
• Baruch Blumberg discovered an antigen in the blood serum of an Australian Aboriginal person that he later (1967) determined to be part of a virus that causes hepatitis B


  1963
• The discovery of the so-called Australia antigen, later called hepatitis B surface antigen (HBsAg), was first described


  1965
• The Dane particle (complete hepatitis B virion) was identified


  1970

  
• A plasma-derived Hepatitis B (HepB) vaccine was first licensed for use in the United States


  1981

  
• Recombinant HepB vaccines replaced plasma-derived HepB vaccines beginning in 1986. Plasma-derived HepB vaccines are no longer used in the United States
• Recombinant HepB vaccines


  Produced from genetically engineered yeast or mammalian cells
• HBIG


  Derived from donor plasma with high concentrations of antibodies to HBV, provides temporary protection for those who are thought to be exposed
• Hepatitis B Virus


  • Family: Hepadnaviridae
  • Virus Type: small double-stranded DNA

  
• Transmission of Hepatitis B Virus

  • Parenteral or mucosal exposure
  • Sexual
  • Perinatal

  
• Transmission of Hepatitis B Virus


  • Unprotected anal, oral, or vaginal intercourse
  • Mostly in infected semen, saliva, and vaginal secretion
  • Mother-child (vertical)
  • Needle-stick injury from tattooing, from drug users, and by occupation

  
• Serologic markers of Hepatitis B Virus

  • HBsAg
  • Antibody to HBsAg (anti-HBs)
  • Immunoglobulin class M (IgM) antibodies to hepatitis B core antigen (IgM anti-HBc)
  • Immunoglobulin class G (IgG) anti-HBc (IgG anti-HBc)
  • Hepatitis B e antigen (HBeAg)
  • Antibody to HBeAg (anti-HBe)

  
• HBsAg


  Can be detected as early as 1 or 2 weeks and as late as 11 or 12 weeks after exposure to HBV. Transient HBsAg positivity can occur up to 18 days following vaccination (up to 52 days among hemodialysis patients) and is clinically insignificant
• HBeAg


  A marker that is associated with a high number of infective HBV particles in the serum and a higher risk of infectivity

  
• Incubation period of acute hepatitis B

  Typically ranges from 60 to 90 days; other source 30-180 days

  
• Over 90% of infants/newborn, with perinatal HBV, and young children usually are asymptomatic
• Approximately 50% of adults who have acute infections are asymptomatic. Whereas, 10% of children aged 1-5 years and 1/3 of adolescence and adults are seen with symptoms in acute infection
• Preicteric, or prodromal, phase


  From initial symptoms to onset of jaundice usually lasts 3 to 10 days, and is characterized by abrupt onset of fever, malaise, anorexia, nausea, abdominal discomfort, and dark urine beginning 1 to 2 days before the onset of jaundice
• Icteric phase


  Variable but usually lasts from 1 to 3 weeks and is characterized by jaundice, light or gray stools, hepatic tenderness, and hepatomegaly (splenomegaly is less common)
• Convalescent phase


  Lasts weeks to months; malaise and fatigue persist while jaundice, anorexia, and other symptoms disappear
• Most acute HBV infections in adults result in complete recovery (within 6 months) with elimination of HBsAg from the blood and the production of anti-HBs, creating immunity to future infection
• In contrast, as many as 90% of HBV infections in infants progress to chronic infection and 1% develop fulminant liver disease with hepatic necrosis

  
• Acute HBV infection may lead to a severe liver disease such as fulminant hepatitis, cirrhosis, or HCC (hepatocellular carcinoma)

  
• Acute HBV infection


  1. Incubation period of several weeks

  2. Appearance of antiviral antibodies, beginning with immunoglobulin M hepatitis B core antibody (HBcAb)

  3. Window period in which hepatitis B surface antigen (HBsAg) and hepatitis B surface antibody (HBsAb) are not detected

  4. Serologic tests positive for total HBcAb and hepatitis Be antibody (HBeAb)

  
• Potential signs and symptoms of acute HBV infection

  Abdominal and/or joint pain, dark urine, fever, loss of appetite, fatigue, nausea, and vomiting. More severe symptoms, including changes in hemodynamic status and alteration of mentation, dictate the need for hospitalization as a fulminant hepatic failure can present with encephalopathy, or in extreme cases, cerebral edema

  
• Persons with chronic infection are often asymptomatic and may not be aware they are infected; however, they are capable of infecting others and have been referred to as carriers
• Chronic infection is responsible for most HBV-related morbidity and mortality, including chronic hepatitis, cirrhosis, liver failure, and HCC

  
• Approximately 25% of persons who become chronically infected during childhood and 15% of those who become chronically infected after childhood will die prematurely from cirrhosis or liver cancer
• There is no specific therapy for acute HBV infection. Treatment is supportive
• Goals of antiviral therapy for chronic HBV infection

  • Suppression of hepatitis B virus replication
  • Reduction of liver inflammation
  • Prevention of progression to liver cirrhosis and hepatocellular carcinoma

  
• Persons with acute or chronic HBV infections should prevent their blood and other potentially infective body fluids from contacting other persons. They should not donate blood or share toothbrushes or razors with household members. In health care settings, patients with HBV infection should be managed with standard precautions
• As of 2019, hepatitis B vaccines available in the United States are categorized into either single-antigen hepatitis B vaccines or combination vaccines

  
• HBV infection occurs worldwide. The frequency of infection varies in different parts of the world but is more common in some countries in Asia, Africa, South America, and the Caribbean