- What is Hepatitis C virus (HCV)
- Statistics on Hepatitis C virus (HCV)
- Risk Factors for Hepatitis C virus (HCV)
- Progression of Hepatitis C virus (HCV)
- Symptoms of Hepatitis C virus (HCV)
- Clinical Examination of Hepatitis C virus (HCV)
- How is Hepatitis C virus (HCV) Diagnosed?
- Prognosis of Hepatitis C virus (HCV)
- How is Hepatitis C virus (HCV) Treated?
- Hepatitis C virus (HCV) References
What is Hepatitis C virus (HCV)
The hepatitis C virus is a disease of the liver. A virus is an incredibly tiny infectious agent that incorporates itself into the cells of the body, programming them to start producing more of the virus. This causes damage to the cells, but in hepatitis C, the major damage is not actually done by the virus itself. Rather, the major damage caused to the liver is actually due to the inflammation that the body creates trying to fight off the virus. When the body starts to fight the disease, it causes damage to the cells and eventually ‘fibrosis‘ where the liver cells are replaced by tough, but non-functional fibrous tissue.
In chronic cases of hepatitis C, the damage caused by the inflammation is enough to damage the liver; however, unfortunately it is not great enough to completely clear it of the virus. This means that the inflammation continues long term and can eventually cause large amounts of damage. If left unchecked, hepatitis C can eventually lead to cirrhosis of the liver and even hepatocellular carcinoma.
Statistics on Hepatitis C virus (HCV)
Hepatitis is an incredibly common virus worldwide with estimates of around 170 million people being infected. In assessments of healthy blood donors, the rates of infection have been:
- Northern Europe: 0.02%
- Southern Europe: 1-3%
- Africa: 6% (up to 19% in Egypt)
- United States: 0.02%
Within these counties though, there are some groups that are at a higher risk, which is discussed below. It is thought that this high rate of infection with hepatitis C is responsible for 100,000 cases of hepatocellular carcinoma each year, and about the same number of cases of gastrointestinal bleeding.
Risk Factors for Hepatitis C virus (HCV)
While initially the major route of infection was in blood transfusion, current screening techniques mean that this form of transmission has dropped to practically zero. Other forms of blood to blood contact are currently the highest risk factors. Unsafe injecting practice by illicit drug users is currently the highest risk factor for hepatitis C infection. In this population, rates of infection can reach as high as 50 to 90%. Hepatitis C can also be transmitted through occupational exposure, such as the possibility of a ‘needle-stick’ injury by medical staff.
While theoretically hepatitis C could be transmitted sexually and from mother to unborn baby, these modes of transmission are actually very inefficient for hepatitis C. The chances of a sexual or mother to baby transmission have been estimated at around 5%, well below the rates for hepatitis B and HIV. Despite this, people with high-risk sexual behaviour, who have multiple partners and possibly frequent sexually transmitted infections, are at a higher risk of contracting hepatitis C than the general population.
Progression of Hepatitis C virus (HCV)
About 85% of patients with hepatitis C eventually develop a chronic liver disease. If left untreated, chronic hepatitis can lead to cirrhosis in about 15-20% of cases, as well as digestive tract bleeding, liver failure and liver cancerin 7 to 15% of patients. In these patients, the median time from infection to cirrhosis is 30 years, however there is a great deal of variation between individuals. There are several factors which can speed up the progression:
- Duration of infection
- Being male
- Drinking too much alcohol
- Also being infected with HIV
- Low levels of T cells in your blood
Symptoms of Hepatitis C virus (HCV)
Most infections with hepatitis do not actually result in any symptoms. Some people have fairly non specific symptoms such as a ‘flu-like’ illness, loss of appetite, or fatigue but these very rarely lead to diagnosis. However, after infection and progression of the disease, it is more common for patients to complain about extrahepatic symptoms such as fatigue and muscle pain than about specific liver symptoms. Around 74% of patients present with at least one general symptom.
Some symptoms that have a prevalence of greater than one in ten are:
Clinical Examination of Hepatitis C virus (HCV)
There are numerous findings that can be associated with liver failure, however all of these reflect end stage disease and none are specific or helpful in the diagnosis of HCV.
How is Hepatitis C virus (HCV) Diagnosed?
As patients with hepatitis C are usually asymptomatic, it is often picked up only following a routine biochemical test, with liver function tests being slightly odd.
A full blood count can also show some mild changes, secondary to the liver problems.
Liver biopsy is a very useful test in hepatitis C. It is not necessary for diagnosis but gives useful information about the stage of disease (the amount of liver damage that has already occurred). It can also be helpful for ruling out other causes of liver damage.
The virus itself can also be tested for in the bloodstream. This can be helpful in seeing if the infection is present, but also to determine just how much of the virus is present. This can be useful information when predicting response to treatment.
Prognosis of Hepatitis C virus (HCV)
The probable outcome of a viral infection depends a lot of what type of the hepatitis C virus you are infected with. While it is quite complex, there are several different sub types, and each respond to treatment quite differently. These types all appear the same and do not affect how severe the disease is, but only alter their response to treatment. For example, two types have a response rate of 88%, while in others it is a much lower 48%.
How is Hepatitis C virus (HCV) Treated?
It is important to counsel all people, especially high-risk individuals, about the possible sources of hepatitis C infection and to provide adequate information to help avoid them. Once infection has been confirmed through the presence of hepatitis C in the blood along with chronic hepatitis on a liver biopsy, treatment should be started.
The primary therapy is a combination of pegylated interferon and ribivirin. The dosages and duration of treatment vary with the subtype of the infecting virus. Side effects of the treatment can include breakdown of the red blood cells, itching and nasal congestion.
Treatment is monitored through the use of liver function tests and measurements of the amount of the virus in the blood at any time. This is usually done at three months after treatment has begun because at this stage, if treatment has not worked adequately then it is unlikely to have much of an effect in the future.
Hepatitis C virus (HCV) References
- Braunwald E, Fauci AS, Kasper DL, et al. Harrison’s Principles of Internal Medicine (16th edition). New York: McGraw-Hill Publishing; 2005. Book
- Kumar P, Clark M (eds). Clinical Medicine (5th edition). Edinburgh: WB Saunders Company; 2002. Book
- Cotran RS, Kumar V, Collins T, Robbins SL. Robbins Pathologic Basis of Disease (6th edition). Philadelphia: WB Saunders Company; 1999. Book
- Poynard T, Yuen MF, Ratziu V, Lai CL. Viral hepatitis C. Lancet. 2003; 362(9401): 2095-100. Available from: [Abstract]