Hepatitis B Fahad Alanazi

What is Hepatitis B? Hepatitis B is an infectious liver inflammation It caused by Hepatitis B virus.

Pathogen: Hepatitis B virus It is from the hepadnavirus family It is an enveloped DNA virus that is only partly double stranded and forms a circle

Hepatitis B virus Cont. Neuclocapsid: Hepatitis B core antigen (HBcAg) Envelope: Hepatitis B surface antigen (HBsAg) One segment of HBcAg: Hepatitis B e antigen (HBeAg) - Viral replication and high infectivity DNA polymerase reverse transcriptase: target for antiviral therapy The nucleocapsid contains the hepatitis B core antigen (HBcAg). This nucleocapsid is encompassed with an outer envelope called the hepatitis B surface antigen (HBsAg). One segment of HBcAg results in the hepatitis B e antigen (HBeAg), which is associated with viral replication and high infectivity. The DNA polymerase reverse transcriptase is a target for antiviral therapy

Types of Hepatitis B virus Acute (short-term) illness Chronic (long-term) infections

1. Acute (short-term) illness Usually come with symptoms. These symptoms are: Loss of appetite Diarrhea and vomiting Tiredness Jaundice Abdominal Pain Muscle and joints pain It comes more in adults than children

2. Chronic (long-term) infections If the hepatitis B persists to more than 6 months is called chronic hepatitis B infection. It comes more in infants and children than adults. It usually comes without symptoms It may lead to Liver damage (cirrhosis) Liver cancer Death

Mode of transmission of HBV Contact with the blood or body fluids such as blood transfusion cuts and sores Contact with a contaminated object, such as toothbrushes, razors. Having unprotected sex with hepatitis B person Sharing injecting needle drugs. A baby whose mother is infected can be infected at birth Children, adolscenents and adults can become infected by

Pathogenesis Hepatitis B virus primarily interferes with the functions of the liver by replicating in liver cells The virus does not directly kill hepatocytes. The host’s immune response to viral antigens is thought to be the cause of the liver injury in HBV infection (cellular immune response)especially antigen- specific T lymphocyte response

Diagnosis physical examination blood tests liver function tests

Blood tests specific for hepatitis B HBsAg (hepatitis B surface antigen) A positive result= person with active infection that is maybe acute or chronic infection. Antibody to HBsAg (Anti-HBs) A positive result= person immune to hepatitis B either from having a past hepatitis B virus or having the HBV vaccine. Presence of this antigen triggers an antibody response. This refers to the protective antibody that is produced in response to an infection. It appears when a person has recovered from an acute infection and cleared the virus (usually within six months) or responded successfully to the hepatitis B vaccine shots. A "positive" or "reactive" HBsAb (or anti-HBs) test= a person is "immune" to any future hepatitis B infection and is no longer contagious.

Blood tests Cont. Antibody to hepatitis B core antigen (Anti-HBc) A positive result = present or past infection. Hepatitis E surface antigen (HBeAg) Indicates how well the hepatiis B person will spread the virus to others The hepatitis B DNA test To measure the viral load This help to monitor the effectiveness of antiviral drugs This refers to an antibody that is produced in response to the core-antigen, a component of the hepatitis B virus. However, this is not a protective antibody. In fact, it is usually present in those chronically infected with hepatitis B. A "positive" or "reactive" HBcAb (or anti-HBc) test= a past or present infection, but it could also be a false positive. The interpretation of this test result depends on the first two test results. Its appearance with the protective surface antibody (positive HBsAb or anti-HBs) indicates prior infection and recovery. For chronically infected persons, it will usually appear with the virus (positive HbsAg).

Tests to measure liver function Bilirubin Liver Enzymes (Aminotransferases): including aspartate (AST) and alanine (ALT) serum Albumin Concentration Liver Biopsy
 The E antigen blood test A test to determine how likely to spread HBV to others by looking for the presence of a protein secreted by HBV-infected cells. A positive result= high levels of the virus in the blood and can easily infect others. A negative result= lower blood levels of HBV and are less likely to spread the infection. . Liver function tests may gauge the amount of damage that has occurred in your liver cells. During a liver biopsy, your doctor inserts a thin needle through your skin and into your liver A small sample of liver tissue is removed for laboratory analysis. A biopsy may show the extent of any liver damage and may help determine the best treatment for you.

Treatment Treatment to prevent hepatitis B infection after exposure Call the doctor immediately to receive hepatitis B immune globulin which may help in protecting from the development of hepatitis B. Treatment for acute hepatitis B infection It may not need treatment, work to reduce any signs and symptoms and monitor blood tests If you've been diagnosed with chronic hepatitis B infection, your doctor may recommend: Several medications are available. Your doctor can suggest which medications may be most appropriate for you. During a liver transplant, the surgeon removes your damaged liver and replaces it with a healthy liver. Most transplanted livers come from deceased donors, though a small number come from living donors Acute — meaning it is short-lived and will go away on its own

Treatment Cont. Treatment for chronic hepatitis B infection Antiviral medications to kill the virus and slow the process of damaging the liver. Liver transplant. In cast the liver has been severely damaged.

Prevention Hepatitis B vaccine: 3 doses (1st at birth: 2nd at 1-2 months: 3rd at 6-18 months) Do not have sex with an infected partner Use a new latex or condom every time you have sex Stop using illicit drugs Be cautious about body piercing and tattooing Don’t share contaminated objects such as needle, razor.

References http://www.hepb.org/patients/your_blood_tests.htm http://www.mayoclinic.com/health/hepatitis- b/DS00398/DSECTION=treatments%2Dand%2Ddrugs http://www.mayoclinic.com/health/hepatitis- b/DS00398/DSECTION=tests%2Dand%2Ddiagnosis http://health.nytimes.com/health/guides/disease/hepatitis -b/diagnosis.html