Blood to Blood Contact
Hepatitis B can be transmitted (passed on) through contact with the blood of an infected person. This is commonly referred to as blood to blood contact.
The virus cannot 'travel' by itself. It needs a 'vehicle' to get from one person's bloodstream to another's. The vehicle in this case is anything that can cut, nick or scratch the skin enough to draw blood. How you get Hep B therefore varies as there are different ways for this to happen.
There are three important steps to infection.
Here is an example of how this might happen:
An infected drug user helps his girlfriend inject with the same needle he has just used. A drop of his blood enters her bloodstream via the needle. Perhaps it is the one and only time she ever uses drugs intravenously. It makes little difference to the virus; as long as it is able to establish itself, she will get Hepatitis B.