Causes and modes of transmission
What causes hepatitis?
Hepatitis can be caused by:
- Viruses (HAV, HBV, HCV, HDV, HEV and other viruses)
- Substances that are toxic to the liver (alcohol, medicines, chemical products etc.)
- some auto-immune diseases.
How are the various hepatitis viruses transmitted?
Hepatitis A
Mainly via the faecal-oral route (direct of indirect contact with infected faeces):
- consumption of contaminated food or contaminated water
- during sexual relations with oral-anal contact (STI) [1].
Hepatitis A and E are much more common in countries with poor hygiene conditions.
Hepatitis B
Mainly through percutaneous/mucosal contact with infected blood or bodily fluids (sperm, saliva, etc.):
- During sexual relations without a condom with an infected person (STI)
- through infected blood (a needle prick, sharing drug-related injection equipment etc.)
- from mother to child.
Hepatitis C
Mainly percuataneous/mucosal contact with blood/blood products:
- via infected blood (sharing drug-related injection equipment, a blood transfusion or organ transplant prior to 1990, medical injections with infected equipment, a needle prick, a tattoo or piercing with unsterilised equipment, etc.)
- During sexual relations without a condom (STI), with exposure to blood (traumatic sexual relations, wounds etc.)
- from mother to child.
Hepatitis D
- Only people who are infected with HBV can contract hepatitis D. Co-infection with HDV and HBV simultaneously can aggravate the evolution of hepatitis B. Vaccines against hepatitis B also indirectly protect against an HDV infection.
- Transmission occurs through exposure to infected blood, blood products or other bodily fluids.
Hepatitis E
- The consumption of food or contaminated water (for genotype 1 often infection via faeces in endemic countries; for genotype 3 often infection via processing raw pork products in food).
- Via infected blood on rare occasions (transfusion of infected blood products).