Hepatitis B (Serum Hepatitis)

  • hepatitis bHepatitis B is the inflammation of the liver caused by hepatitis B virus.
  • This is considered to be more serious than hepatitis A due to the possibility of severe complications such as massive damage and hepatocarcinoma of the liver.
  • Hepatitis B is a viral infection that attacks the liver and can cause both acute and chronic disease.About 2 billion people worldwide have been infected with the virus and about 350 million live with chronic infection.
  • An estimated 600 000 persons die each year due to the acute or chronic consequences of hepatitis B.
  • About 25% of adults who become chronically infected during childhood later die from liver cancer or cirrhosis (scarring of the liver) caused by the chronic infection.
  • The hepatitis B virus is 50 to 100 times more infectious than HIV.
  • Hepatitis B virus is an important occupational hazard for health workers.
  • Hepatitis B is preventable with a safe and effective vaccine.

Etiologic Agent:

The disease is caused by Hepatitis B virus

1. This virus has very limited tissue tropism

2. HBV infects the liver and possibly the pancreas.

3. HbsAg appears in the blood 30 to 60 days after exposure and persists for variable periods of time.

Incubation Period:

The incubation period is 50 to 189 days or two to five months with a mean equal to 90 days.

Period of Communicability:

The patient is capable of transmitting the virus during the latter part of the incubation period and during the acute phase. The virus may persist in the blood for many years.

Mode of Transmission:

  1. Hepatitis B can be directly transmitted by person to person contact via infected body fluids.
  2. It can be transmitted though contaminated needles and syringes.
  3. Transmission can occur through infected blood or body fluids introduced at birth.
  4. It can also be transmitted through sexual contact.

HBV transmission does not occur.

  1. by fecal-oral route
  2. by food-borne or water-borne transmission
  3. by arthropod (mosquito) transmission.

Pathogenesis:

  1. HBV can cause acute or chronic hepatitis.
  2. Production of virus and high level of HbsAg is continuous and the particles are found in the blood until the infections is resolved.
  3. The virus must be delivered into the liver to establish infection.
  4. The virus replicates and large amount of HbsAg is released into the blood.
  5. Initiation of virus replication may be as short as three days from acquisition, but symptoms may not be observed for 45 days or much longer.
  6. Replication of the virus is not cytopathic and proceeds to relatively long periods without causing liver damage.
  7. During the acute phase of infection, the liver parenchyma shows degenerative changes consisting of cellular swelling and necrosis, especially in hepatocytes.

Clinical Manifestations:

  1. Prodormal period
      • Fever, malaise, and anorexia.
      • Nausea, vomiting, abdominal discomfort, fever and chills.
      • Jaundice, dark urine, and pale stools.
      • Recovery is indicated by a decline of fever and improved appetite.
      1. Fulminant hepatitis may be fatal and manifested by severe symptoms like ascitis and bleeding.

      Diagnostics Procedures:

      1. Compliment fixation test
      2. Radio-immunoassay-hemaglutinin test
      3. Liver function test
      4. Bile examination in blood and urine
      5. Blood count
      6. Serum transaminase – SGOT, SGPT, ALT
      7. HbsAg

      hepatitis b vaccine Prevention:

      1. Blood donors must be screened to exclude carriers.
      2. Caution must be observed in giving care to patients with known HBV.
      3. Hands and other skin areas must be washed immediately and thoroughly after contact with body fluids.
      4. Avoid injury with sharp objects or instruments.
      5. Use disposable needles and syringes only once and discard properly.
      6. Avoid sharing of toothbrush, razor, and other instruments that may be contaminated with blood.
      7. Observe “safe sex”.
      8. Have adequate rest, sleep, and exercise and eat nutritious food.
      9. Hepatitis B vaccine is recommended for pre-exposure.
      10. Hepatitis Immune Globulin (HBIg) should be administered within 72 hours to those exposed directly to hepatitis B virus either by ingestion, by prick or by inoculation.

      More About Hepatitis

      Source:

      Handbook of Common Communicable and Infectious Diseases 2006 Ed

      World Health Organization

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