1. Hepatitis B Sophie Masterson C14316906

2.  Hepatitis B is a potentially life-threatening liver infection caused by the hepatitis B virus.  It is a major global health problem.  It can cause chronic infection and puts people at high risk of death from cirrhosis and liver cancer. What is it?

3.  In highly endemic areas (Sub-Saharan Africa and East Asia), hepatitis B is most commonly spread from mother to child at birth (perinatal transmission),  or through horizontal transmission (exposure to infected blood), especially from an infected child to an uninfected child during the first 5 years of life.  Hepatitis B is also spread by percutaneous or mucosal exposure to infected blood and various body fluids, as well as through saliva, menstrual, vaginal, and seminal fluids.  Transmission of the virus may also occur through the reuse of needles and syringes either in health-care settings or among persons who inject drugs. In addition, infection can occur during medical, surgical and dental procedures. Transmission

4.  Most people do not experience any symptoms during the acute infection phase.  However, some people have acute illness with symptoms that last several weeks, including:  yellowing of the skin and eyes (jaundice)  dark urine  extreme fatigue  nausea  vomiting and  abdominal pain.  A small subset of persons with acute hepatitis can develop acute liver failure which can lead to death.  In some people, the hepatitis B virus can also cause a chronic liver infection that can later develop into cirrhosis of the liver or liver cancer.  More than 90% of healthy adults who are infected with the hepatitis B virus will recover naturally from the virus within the first year. Symptoms

5.  The basic structure of the complete virion is 42nm in diameter and double-shelled, known as a Dane particle (circular in shape) which is made up of an envelope protein (HbsAg), a Core protein C and a circular DNA.  HBcAg (core antigen) is located in the centre and is 27nm.  HBeAg an antigen that circulates and is soluble in serum.  The virus can also be in the form large, middle or small spheres or tubules (containing only the surface antigen). What are the components of Hep B?

6. Fig 1(a) Electron Micrograph of Hepatitis BFig 1(b) Basic Structure of a Dane particle

7.  Hepatitis A - less severe form of hepatitis, RNA virus, transmitted by the enteric route.  Deltavirus - HDV associated agent of HBV, very small RNA virus, it is a satellite as it depends on HBV to provide its envelope protein.  Hepatitis C - transmitted by exposure to blood and body fluids, very liable to cause chronic infections e.g. cirrhosis of the liver.  Hepatitis E – resembles HAV in being primarily spread by ingestion but has been proved to be a calicivirus. Caliciviruses infect humans and animals and cannot be grown in culture. What disease is it related to?

8.  ELISA - enzyme-linked immunosorbent assay, a sensitive immunoassay that uses an enzyme linked to an antibody or antigen as a marker for the detection of a specific protein, especially an antigen or antibody.  Viral DNA or RNA detection tests - Using a sample of tissue or blood or other fluid this type of test can be carried out to look for viral DNA or RNA polymerase as a measure of viral replication.  Full marker profile - may be found by testing, by variants of ELISA, for the 3 antibodies; anti-HBs, anti- Hbe and anti-HBc.  Electron microscopy - a technique that involves microscopes that use electrons rather than visible light to produce magnified images, it can be used to test quickly for both HBsAg and infective Dane particles – they are very numerous when present so they are easy to find in serum. However this method is unsuitable for a large no. of specimens.  PCR – Polymerase Chain Reaction is a technique for amplifying DNA sequences in vitro by separating the DNA into two strands and incubating it with oligonucleotide primers and DNA polymerase. It can amplify a specific sequence of DNA as many as one billion times Methods to investigate the disease

9.  Reverse passive haemagglutination – commercially available RBCs coated with anti-HBs are mixed with the test serum, any HBsAg present will attach to the antibody and agglutinate the cells within 20 minutes.  Latex slide test – is based on the principle of agglutinating antibodies against the HB antigens commercially made, agglutination is obvious and can be done in 5 minutes. This is a positive rapid test but must be confirmed by ELISA. Commercially Available Tests

10.  Hepatitis B Rapid Screen Test - detects Hepatitis B in whole blood/serum/plasma. The test kit is easy to use at home and gives you 98% accurate result in just 15 minutes. It can be ordered online at the price of $24.  The following video gives a step by step tutorial on how to use the self-test kit.  https://www.youtube.com/watch?feature=player_emb edded&v=V5LY5FaAc9A https://www.youtube.com/watch?feature=player_emb edded&v=V5LY5FaAc9A Self-test Kits

11.  There is a positive internal control within the test kit.  It works on the following principle; if a single line appears beside the indicator ‘C’ then the control has worked and you can trust that the test results are correct.  If no line appears where the control should be, then you cannot use the test to self diagnose.  External Quality Control is conducted on these test kits to ensure they are working and are accurate.  Quality Marks are awarded to most available self-test kits.  The test and results are as accurate as clinical testing.  The test kits are CE marked as per European standards and the laboratory is CPA approved. Controls

12.  A vaccine against hepatitis B has been available since 1982. The vaccine is 95% effective in preventing infection and the development of chronic disease and liver cancer due to hepatitis B. Vaccination

13.  Collier L, Kellam P and J Oxford, (2011) The blood-borne hepatitis viruses B and D.In Human Virology, 4 th Ed, New York, Oxford University Press.  Specter S, (1999) Hepatitis B Virus.In Viral Hepatitis Diagnosis, Therapy and Prevention, New Jersey, Human Press Inc.  Blumberg B S, (2002) Identifying the Hepatitis B Virus.In The hunt for a killer virus Hepatitis B, New Jersey, Princeton University Press.  Fig 1(a) Fig 1(b) Wikipedia, https://en.wikipedia.org/wiki/Hepatitis_B, accessed 13 th February 2016.https://en.wikipedia.org/wiki/Hepatitis_B  Priva Path Diagnostics, (2015) Let’s get checked, https://www.letsgetchecked.com/sti-test-kits/standard-6/?gclid=CN7T3Nnt- soCFYvnwgod5rkGPg,accessed 15 th February 2016. https://www.letsgetchecked.com/sti-test-kits/standard-6/?gclid=CN7T3Nnt- soCFYvnwgod5rkGPg  World Health Organisation, (2015) Hepatitis B Virus http://www.who.int/mediacentre/factsheets/fs204/en/, accessed 12 th February 2016. http://www.who.int/mediacentre/factsheets/fs204/en/ Reference List