Hepatitis B is a liver disease that results from infection with the hepatitis B virus (HBV) and is spread through contact with infected body fluids or blood products. Following acute infection with HBV, some people go on to develop a chronic infection.
Transmission routes and symptoms
Hepatitis B is spread through contact with contaminated body fluids. Most infections occur by coming into contact with infected blood but semen, saliva and cervical secretions can also be infectious.
The virus can live on surfaces for at least seven days which means it can be transmitted via objects that have been contaminated with infected body fluids (e.g. used needles). Sexual transmission and injecting drug use are the most common current routes of transmission in Europe.
Transmission may also occur in healthcare settings due to the reuse or inadequate sterilisation of medical equipment, especially syringes and needles. Transmission via blood transfusion or through the use of plasma-derived products is now rare in Europe due to effective blood safety programmes.
Whilst many individuals have no symptoms associated with the acute infection, those who do may experience tiredness, loss of appetite, abdominal discomfort, nausea, vomiting and fever.
The development of chronic HBV infection is inversely associated with the age at which the individual is infected. Up to 90% of infants who are infected with the virus develop chronic infections but less than 5% of infected adults develop chronic infection. Individuals with chronic HBV infection are at a higher risk of complications including liver cirrhosis (25%) and cancer (5%). In addition, they may be at risk of transmitting the infection to others.
Thanks to testing programmes during pregnancy and vaccination at birth, perinatal HBV transmission now only occurs rarely in Europe but remains one of the major routes of transmission globally.
High level of protection: the hepatitis B vaccine
The hepatitis B vaccine is the mainstay of hepatitis B prevention. Safe and effective vaccines are available that offer high levels of protection and most countries in Europe have implemented a universal vaccination programme.
With evidence of on-going transmission and continuing importation of cases, these vaccination programmes are essential in order to achieve the target of hepatitis elimination by 2030.
In addition to vaccination programmes the implementation of blood safety strategies and safe injection practices can prevent transmission of HBV. Safer sex practices can also protect against transmission.