Hepatitis A is usually a mild disease that does not become chronic (i.e. cause long-term health problems). It is passed on via food and water contaminated with faeces (shit) from an infected person and occasionally via oral/anal sexual contact.

Hepatitis B is a blood borne virus which is transmitted via blood and other body fluids including saliva, semen, vaginal secretions and breast milk. It is not passed on via water contamination or in food. It becomes chronic for a small proportion of adults and almost all small children who are infected.

Hepatitis C is also a blood borne virus; however, unlike Hep B it is found only in blood. It is not considered a sexually transmitted infection and cases of Hep C transmission involving sexual contact also involve quantities of blood. It is not transmitted via food or water contamination. It becomes chronic (i.e. long term) for about three-quarters of all people infected with the virus.

There are several strains or genotypes of Hep C as well as different subtypes of each strain. These strains are different in their genetic make-up, but are similar enough to still be labelled Hep C. There are six different genotypes (or strains) of the Hep C virus (1 to 6), with the prevalence of different genotypes varying from country to country, for example genotypes 1 and 3 are most common in Australia. It is possible for users who continue high-risk practices to be infected with a different strain or be re-infected with the same strain.

There are vaccines for both Hep A and B; however, there is no vaccine for Hep C.