Hepatitis means inflammation of the liver. This can be caused by a variety of factors, including heavy alcohol or drug use, drug toxicities and viral infections. Shared transmission routes mean that many people infected by HIV are also at risk of viral hepatitis. This chapter looks at a number of hepatitis viruses alongside key features relevant to co-infection with HIV.

The liver serves three functions: it stores and filters blood, removing toxic substances from drugs, food or body waste; it makes bile, a liquid which is stored in the gall bladder and released into the gut to help digest fat; and it metabolizes nutrients from food, releasing energy into the bloodstream and storing vitamins and minerals.

All of the viral pathogens which cause hepatitis are labelled with letters currently ranging from A to E. Leading virologists and hepatologists expect more as yet undiscovered viruses to be identified in the future - although no one has worked out what to do if we ever reach the letter Z. These viruses are grouped simply because they are all known, or believed to, inflame the liver. However the genetic make-up and characteristics of these viruses are often entirely different. Some of them are chronic infections like HIV and some only occur as acute infections. An acute infection is one that is resolved within six months and a chronic infection one that persists beyond six months. Some of these chronic viral infections have an 'acute phase' which is a period of symptoms experienced when a person is initially infected with the virus. These initial infection symptoms often pass although the person may then develop symptoms of the chronic infection.

The damage these viruses cause can be classified as either cytopathic or immunopathic. Cytopathic means the virus causes damage directly, by injuring the cells that it infects while immunopathic means that it is the response of the body's immune system to the viruses that causes the damage.

This chapter focuses mainly on the two most concerning hepatitis viruses in the UK, Hepatitis B and C with a brief mention of the other known hepatitis viruses. The names for each hepatitis virus is often abbreviated to HAV for Hepatitis A Virus, HBV for hepatitis B and so on. Fortunately we have not got to Hepatitis I as this would be confusing.

Vaccines are available for some forms of viral hepatitis but not for others. It is recommended that HIV-positive people receive vaccinations against hepatitis A and B (BHIVA guidelines). Treatments are available for some forms of viral hepatitis while others types are resolved naturally.

Many HIV treatments are processed through the liver and so it is important to try and keep the organ in good shape. Having one of these viruses along with HIV is not a good thing for the liver and having two or more probably even worse. Therefore, it is important for all HIV-positive people to be tested for hepatitis A and B and to get vaccinated against them if necessary. Similarly the choice of anti-HIV agents is important for people who have viral hepatitis or a damaged liver. For a complete discussion of current therapeutic options for HIV-HCV co-infected individuals, see the HIV & AIDS Treatments Directory.