Hepatitis is an inflammation of the liver that causes irritation and swelling in the cells. Hepatitis C is caused by a virus.
It is estimated that about 250 million people world-wide are infected with hepatitis C, approximately 2 per cent of the population of the US. Between 28,000 and 35,000 cases of acute hepatitis C occur each year. Only about 25 to 30% of people with hepatitis C are diagnosed because the majority of people have no symptoms.
Hepatitis C is a virus that is very difficult to clear from the body. 85% of people with acute hepatitis C progress to its chronic form.
Hepatitis C does its damage slowly with the person usually unaware of any symptoms. In fact 20% of people with chronic hepatitis C experience no symptoms of the disease although they may well experience signs and symptoms of infection in other organs, known as 'extrahepatic', in other words, outside the liver. These types of infection, known as immune-complex mediated diseases, include skin diseases, vascalitis (inflammation of the blood vessles), porhyria cutaenea tarda (a person finds they bruise easily), blood related abnormalities, endocrine disorders, eye disorders such as corneal ulcers, muscle weakness and joint pains. It is these symptoms that may alert a doctor to the possibility of a liver disease.
Different Strains of Hepatitis C
The genes that make up the HCV vary. These so called genotypes have been numbered 1 to 6. Some researchers believe there may be more, (genotypes 7 to 11), however this is still being investigated. Each genotype can differ by as much as 35%. These “sub-types” are classified alphabetically, a, b and c.
Different genotypes seem to predominate in different parts of the world. Type 1a and 1b are common in America whereas genotype 2 and 3 seem more commonly in Europe. The different types are important as they respond differently to the current treatments that are available.
Importance of genotype
Studies indicate that Type 1 especially type 1b does not respond well long term to treatment with Interferon. Some investigators have shown that people with type 1b tend to develop more severe problems, their disease is often more aggressive and so cirrhosis and liver cancers occurs more often. However other researchers believe there is insufficient data to be
conclusive.
Transmission of Hepatitis C
Hepatitis C is transmitted primarily by blood to blood contact. A person becomes infected with the hepatitis C virus by having an infected persons blood mixed with their blood in some way. As with hepatitis B, exposure can occur from blood transfusions (prior to 1990), tattooing and body piercing, occupational exposure, medical procedures, or from intravenous drug use. Transmission can also occur during sexual contact (anal, oral or genital) although it has been shown to be an inefficient route of exposure, as has mother to child infection during childbirth.
Article Sources:
Palmer, Mellisa. Hepatitis Liver Disease. What you need to know. New York: Avery Publishing Group, 2000.
CDC Center for Disease Control,
WHO World Health Organization