About the hepatitis C virus

Hepatitis C is a blood-borne virus that predominantly infects the cells of the liver. This can result in inflammation and significant damage to the liver. It can also affect the liver’s ability to perform its essential functions. Although it has always been regarded as a liver disease - ‘hepatitis’ means ‘inflammation of the liver’ - recent research has shown that the hepatitis C virus (HCV) affects a number of other areas of the body. These can include the digestive system, the lymphatic system, the immune system and the brain.

Hepatitis C was first discovered in the 1980s when it became apparent that there was a new virus (not hepatitis A or B) causing liver damage. Before being properly identified in 1989 it was originally known as non-A non-B hepatitis. In 1991 a screening process was developed making it possible to detect HCV in blood samples. As a relatively new disease there are still many aspects of hepatitis C which are yet to be fully understood.

There are an estimated 150 million people worldwide chronically infected with hepatitis C. The level of infection, known as prevalence, varies widely from country to country. In some countries, such as Egypt, it is as high as15%. In the United States it is believed to be 1% and in the UK it is believed to be around 0.5%. The virus can only be transmitted by infected blood.

Hepatitis C is an RNA virus. RNA viruses mutate much more than DNA viruses. This ability to mutate makes the RNA virus much harder for the body’s immune system to locate and destroy it. In hepatitis C there are 6 major variations of the virus, labelled 1 to 6. These are known as ‘genotypes’. Different genotypes predominate in different parts of the world. One genotype cannot change into another. However, it is possible, although rare, to be infected with more than one genotype at the same time.

A hepatitis C infection can be categorised into two stages. The first stage is acute infection (following initial infection). The second stage is chronic infection. The acute stage refers to the first 6 months of infection and does not necessarily result in any noticeable symptoms. Approximately 20% of those infected with hepatitis C will naturally clear the virus from their body within the first six months. For the remaining 80% a chronic (long-term) infection will develop.

The course of a chronic hepatitis C infection is extremely varied and unpredictable. Some people experience very few symptoms for as long as a decade. Others can suffer symptoms almost from the start. Some will progress to develop fibrosis and cirrhosis (scarring) of the liver, liver cancer or end stage liver disease, while others experience very little liver damage, even after many years. In cases where there is an absence of symptoms many people do not discover that they have HCV until some time after they have been infected.

Another reason that hepatitis C goes undiagnosed for many years is that its symptoms can often be put down to other illnesses. For example, depression, fatigue, skin problems, insomnia, pain and digestive disorders could all have other causes. For these reasons hepatitis C is often referred to as the ‘Silent Epidemic’.

Drug treatment to eradicate the virus has advanced greatly in the last few years. The success rates for genotype 1 are now as high as 70% . Genotype 2 still seems to be the easiest to treat, having a success rate of 80%. Genotype 3 treatment is successful in approximately 70% of people. Genotype 4 treatment seems to be successful in approximately 40% of cases. However, the treatment can have significant side effects and is definitely not suited to everyone. A vaccine remains some time off.

What is a virus

All recognised life-forms are susceptible to the threat of viruses entering their cells where they exist as parasites.

Genotypes of hepatitis C

There are six recognised genotypes of the hepatitis C virus. The most common in the UK are genotypes 1 and 3.