Information for healthcare professionals on the diagnosis, prevention and treatment of hepatitis B.
Hepatitis B is a virus that replicates in the liver, but is also present at very high levels in the blood of people who are infected. The hepatitis B virus (HBV) causes hepatitis (inflammation of the liver) and can also cause long term liver damage. It is vaccine preventable.
The virus may be transmitted by contact with infected blood or body fluids contaminated by blood. The virus can be spread by:
- sharing or use of contaminated equipment during injecting drug use
- vertical transmission (mother to baby) from an infectious mother to her unborn child
- sexual transmission
- horizontal transmission (non-sexual contact between individuals , for example household contact with an infected person)
- receipt of infectious blood (via transfusion) or infectious blood products (for example clotting factors) in countries where screening of blood donors and donations is not performed.
- needle stick or other sharps injuries (in particular those sustained by hospital personnel)
- tattooing and body piercing
The incubation period from infection to the appearance of symptoms is around 12 weeks (range 40-160 days).
Exposure to the hepatitis B virus causes an acute infection. Symptoms during acute infection can include tiredness, abdominal pain, a “flu-like illness”, nausea, vomiting, joint pains, loss of appetite and jaundice. Children rarely develop acute symptomatic hepatitis B infection whereas up to a third of adults are symptomatic during this acute stage of infection. Individuals are infectious to others and mortality during the acute phase of infection is estimated to be less than 1%.
If the virus persists for greater than 6 months, the person has developed chronic (persistent) hepatitis B infection. During chronic infection many people have no symptoms but will remain persistently infected and infectious to others. Chronic hepatitis B infection is more likely to develop if the infection is acquired in childhood. Up to 10% of adults will develop chronic hepatitis B infection if the infection is acquired in adulthood. Progressive chronic infection is characterised by ongoing liver disease. The long term complications of chronic hepatitis B infection include cirrhosis and primary liver cancer.
Laboratory diagnosis of hepatitis B involves serological testing for several hepatitis B specific antigens and antibodies. Different serological “markers” or combination of markers are used to identify phases of HBV infection and to determine whether a patient has acute or chronic HBV infection, is immune to HBV as a result of prior infection or vaccination, or is susceptible to infection. The hepatitis B markers are:
- hepatitis B surface antigen (HBsAg)
- total antibody to hepatitis B core antigen (anti-HBc total)
- antibody to hepatitis B surface antigen (anti-HBs)
- antibody to hepatitis B core antigen immunoglobulin M (anti-HBc IgM)
- hepatitis B e antigen (HBeAg)
- antibody to hepatitis B e antigen(anti-HBe)
Additional tests for hepatitis B include quantification of HBV DNA (often referred to as HBV viral load) and HBV core avidity testing. This additional testing and interpretation of results can be obtained from PHE Colindale’s Blood Borne Virus Unit .
For surveillance purposes, acute hepatitis B infection is defined as HBsAg positive and anti-HBc IgM positive with abnormal liver function tests plus a clinical pattern consistent with acute viral hepatitis. As acute hepatitis B flares can occur during chronic persistent infection, HBV core avidity testing may be done to differentiate between an acute and chronic infection and a follow up sample should be obtained. PHE Colindale’s Blood Borne Virus Unit provide reference laboratory services for hepatitis B.
Treatment and prevention
Acute hepatitis B infection is self-limiting and only treatment to relieve the symptoms is offered. Currently there is no indication to treat these people with antiviral drugs. People who develop persistent infection (including infants born to hepatitis infected mothers who have evidence of infection at 12 months old) need to be referred to a liver specialist. Treatment with drugs able to suppress the virus is likely to benefit the patient and decrease the likelihood of disease progression. Not all patients are suitable for treatment. Further information is available at NICE Clinical Knowledge Summaries.
When an individual (recipient) is thought to have been exposed to blood from another individual (donor), a HBV risk assessment should be done to determine whether post exposure prophylaxis is indicated. Where possible the HBV status of the donor should be obtained. Where a blood or sexual exposure has led to a perceived HBV risk, post exposure immunisation with hepatitis B vaccine should be considered. High risk exposures to a person known to be infectious for HBV may warrant consideration of hepatitis B immunoglobulin (pre-prepared antibodies against infection).
Post exposure prophylaxis recommendations are in the Immunisation against infectious disease “The Green Book”, which are based on the PHLS Hepatitis Sub-Committee guidance on post exposure prophylaxis.
Advice is also available from Health Protection Teams and through the Immunisation, Hepatitis and Blood Safety Department and the Virus Reference Department at PHE Colindale.
Information and guidance on prevention of hepatitis B in healthcare occupational settings is available. The UK advisory panel (UKAP) enquiry proforma form is available the UK advisory panel for Healthcare Workers Infected with Bloodborne Viruses page.
Vaccine uptake among men who have sex with men
Data on hepatitis B vaccine uptake among men who have sex with men (MSM) were collected from genitourinary medicine (GUM) clinics in England between January 2003 and June 2008 inclusive, through the HepB3 Survey. The National Strategy for Sexual Health and HIV (Department of Health), 2001 recommended that all MSM should be offered hepatitis B vaccination at their first attendance at a GUM clinic. Measures of course uptake, completion and adherence among eligible patients were monitored through the HepB3 Survey.