There are five hepatitis viruses defined by types – type A, B, C, D and E. Types B and C are of significant concern since a high proportion of people infected with these viruses may not experience symptoms at the early stage of the disease, and only become aware of their infection when they are chronically ill. This can sometimes be decades after infection. In addition, these two viruses are the leading cause of liver cirrhosis and cancer,accounting for almost 80% of all liver cancer cases.
People can get hepatitis from either infected bodily fluids or contaminated food and water depending on the type of hepatitis.
- Types B, C and D are contracted through the blood of an infected person (e.g. through unsafe injections or unscreened blood transfusions) and in the case of hepatitis B and C, also through unprotected sex.
- Type D only infects persons who are already infected with type B.
- Types A and E are typically transmitted via contaminated water or food and closely associated with poor sanitation and poor personal hygiene (e.g. unwashed hands).
Effective vaccines are available for all the virus types, except C.
In preparation for this year’s World Hepatitis Day, WHO is launching a new global framework to tackle the disease. The Prevention and control of viral hepatitis infection: Framework for global action describes four areas of work to prevent and treat hepatitis infection.
Raising awareness, together with promoting partnerships and mobilizing resources constitute the first of the four priorities in WHO’s new framework. The others are: transforming scientific evidence into policy and action; preventing transmission; and screening, care and treatment.