Hepatitis B Virus
Hepatitis B is a virus that is transmitted from the blood or bodily fluids of the infected person.
It is highly prevalent in Africa and Asia and can potentially cause life threatening complications such as cirrhosis and liver cancer.
Most commonly it is spread by unprotected sex, sharing of needles, blood transfusion or from mother to child. Rarely, it is spread amongst members of the same household. Therefore, as long as not engaging in the above activities, transmission is considered to be of low probability.
Most infected adults clear the infection within a few months, around 95%. However, a few do not clear it, and this is more common with children. They go on to develop chronic Hepatitis B.
They will never clear the infection but can be treated with various antiviral drugs.
In the Western world, Hep B infection is normally associated with immigrants, IV drug users and homosexuals. Hence, many sexual testing clinics will offer Hep B vaccines to gay men due to their higher risk profile.
The vaccine is highly effective and a course is typically delivered over several months or weeks depending on how urgently it is needed.