Causes

Hepatitis B is an infection caused by the hepatitis B virus. The virus is found in the blood and bodily fluids of an infected person.

Many people with hepatitis B have few symptoms and may not know they're infected. They may spread the infection without realising it.

Hepatitis B is most often caught in parts of the world where the infection is more common, although certain groups of people are at risk of picking up the infection in the UK.

How hepatitis B is spread

Hepatitis B can be spread by:

• a mother to her newborn baby, particularly in countries where the infection is common – all pregnant women in the UK are offered screening for hepatitis B; babies of infected mothers are vaccinated immediately after birth to help prevent infection
• injecting drugs and sharing needles and other drug equipment, such as spoons and filters
• having sex with an infected person without using a condom
• having a tattoo, body piercing, or medical or dental treatment in an unhygienic environment with unsterilised equipment
• having a blood transfusion in a country where blood is not tested for hepatitis B – all blood donations in the UK are now tested for the infection
• sharing toothbrushes or razors contaminated with infected blood
• the skin being accidentally punctured by a used needle (needle stick injury) – this is mainly a risk for healthcare workers
• the blood of someone with hepatitis B getting into an open wound, cut or scratch – in rare cases, being bitten by someone with hepatitis B can also spread the infection

Hepatitis B is not spread by kissing, holding hands, hugging, coughing, sneezing or sharing crockery and utensils.

Who's most at risk of hepatitis B

People at highest risk of hepatitis B include:

• people born or brought up in a country where the infection is common
• babies born to mothers infected with hepatitis B
• people who have ever injected drugs
• anyone who has had unprotected sex, including anal or oral sex – particularly people who have had multiple sexual partners, people who have had sex with someone in or from a high-risk area, men who have sex with men, and commercial sex workers
• close contacts, such as family members, of someone with a long-term (chronic) hepatitis B infection

The risk of getting hepatitis B for travellers going to places where the infection is common is generally considered to be low if these activities are avoided.

Your GP can arrange for you to have a blood test to check for hepatitis B and have the hepatitis B vaccination if you're at a high risk.

High-risk areas

Hepatitis B is found throughout the world, but is particularly common in:

• sub-Saharan Africa
• east and southeast Asia
• the Pacific Islands
• parts of South America
• southern parts of eastern and central Europe
• the Middle East
• the Indian subcontinent

Most new cases of hepatitis B in the UK occur in people who caught the infection in one of these areas before moving to the UK.

Page last reviewed: Sun Jan 2022 Next review due: Wed Feb 2020