Viral Hepatitis - Hepatitis A, B and C
Infections of the liver may be caused by any of a number of infectious agents including viruses, bacteria and protozoa. Five major viruses infect the liver causing significant health problems worldwide. These are classified as hepatitis A, B, C, D and E. The diseases caused by the first three will be described, since these are the most common.
Hepatitis A is a liver infection that commonly occurs in children and adolescents, although it can occur at any age. The virus - hepatitis A virus (HAV) - is usually ingested through the mouth from contaminated food or via faeces. Shellfish is identified as the source in 3% of cases. Around 15% of cases are contracted abroad where food hygiene and public health measures are less rigorous.
Hepatitis B liver infection is caused by a Deoxyribonucleic acid (DNA) virus, which is known as the hepatitis B virus (HBV). People who have hepatitis B may become long-term carriers of the virus and a potential source of infection to others.
The virus enters the body either through contact with infected bodily fluids such as blood, semen, saliva etc or by injection of contaminated blood or blood products. This may be as a result of a blood transfusion, a needle stick injury in a clinical setting or via contaminated syringes and needles utilised by drug misusers. Homosexual men are at increased risk of transmission, as are men and women who have multiple sexual partners. In clinical settings surgeons, dentists, midwives and other health care professionals may become infected through their work. People receiving haemodialysis for renal failure are at increased risk, as are the health care professionals attending them. People living and working in long-term institutions such as prisons and residential homes for learning disabilities may develop hepatitis B through close contact.
The virus can also be transmitted from an infected mother around the time of birth to her baby.
Hepatitis C is a liver infection caused by a blood borne Ribonucleic acid (RNA) virus known as the hepatitis C virus (HCV). There are 6 main strains (genotypes) of the virus - G1 to G6. People may be infected with more than one genotype. The disease is commonly acquired by transfusion of infected blood or blood products and through use of syringes and needles contaminated with infected blood. People who misuse illegal drugs by intravenous injection become infected in this way. In this group concurrent infection with HIV and hepatitis B may occur.
The disease can be also transmitted in a number of other ways. These mirror the ways in which hepatitis B is transmitted. However hepatitis C is generally less infectious than hepatitis B. Other modes of infection include: -
- Sexual transmission,
- Mother to baby,
- Through tattooing, ear and body piercing, acupuncture - when blood contaminated equipment is used,
- Close family contact if shaving equipment or tooth brushes are shared,
- Needle stick injuries to health care workers, prison staff etc,
- Through medical and dental procedures in developing countries, where sterilisation and hygiene procedures are less rigorous.
If evidence shows that the customer has cirrhosis, which may have resulted from Chronic Hepatitis C then go to Cirrhosis guidance.
If evidence shows that the customer has liver failure, which may have resulted from Chronic Hepatitis C then go to the Liver Failure guidance.