Hepatitis C is a form of hepatitis (liver inflammation) caused by a virus, the Hepatitis C virus (HCV). Before the virus was discovered, in 1989, the syndrome was initially referred to as a "non-A-non-B hepatitis".
|Hepatitis C virus|
In most cases, acute hepatitis C infection has no symptoms and becomes chronic, and can cause long term damage to the liver, including cirrhosis and hepatocellular carcinoma. Severe liver damage may not develop for 10-40 years after infection. Certain medical phenomena have been associated with the presence of hepatitis C; some are thyroiditis, cryoglobulinemia and some types of glomerulonephritis.
Although it can be spread sexually, and vertically (from mother to child), transmission by these routes is very unlikely, in contrast with hepatitis B. Hepatitis C is not considered a sexually transmitted disease (STD). The CDC reports that only 1.5% of partners of hepatitis C carriers test positive for the disease. In most developed countries, it is usually seen primarily in intravenous drug users.
The hepatitis C virus is a single-stranded, enveloped, positive sense RNA virus in the flaviviridae family. When circulating in the bloodstream, it binds to receptors on liver tissue, most prominently the receptor for low density lipoprotein (LDL).
Hepatitis C infects an estimated 170 million persons worldwide and 4 million persons in the United States. There are around 35,000 to 185,000 new cases of infections a year in the United States. Co-infection with HIV is common and rates among HIV positive populations are higher.
Currently, serological tests are available to check for infection. In addition, PCR can be used for more sensitivity and to elucidate a genotypes for the infection. There are eleven groups, divided by locations. Genotype 1a is the most common in North America, and 1b in Europe.
The infection is spread by blood exchange and, less commonly, sexual contact. Before serological tests became available, it was often caused by the use of medical products derived from blood and by blood transfusion.
Though hepatitis A, hepatitis B, and hepatitis C have similar names (because they all cause liver disease) the viruses themselves are quite different. Unlike hepatitis A and B, there is no vaccine for hepatitis C.
Treatment is mainly based on interferon alpha (IFN±), combined with other drugs; though this action does not guarantee results. Currently, the preferred treatment is pegylated interferon together with ribavirin. Studies have shown sustained cure rates of 75% or better in people with genotypes 2 or 3 HCV (which is easier to treat) and about 50% in those with genotype 1.
It is well known that alcohol makes HCV associated liver disease progress faster, and makes interferon treatment less effective.
Hepatitis C co-infection with HIV
Approximately 40% of U.S. patients infected with HIV are also infected with the hepatitis C virus (HCV), mainly because both viruses share the same routes of transmission. HCV is one of most important causes of chronic liver disease in the U.S. It has been demonstrated in clinical studies that HIV infection causes a more rapid progression of chronic hepatitis C to cirrhosis and liver failure in HIV-infected persons.
Alternative and experimental therapies
Several "alternative therapies" purport to reduce the liver's duties, rather than treat the virus itself, thereby slowing the course of the disease or keeping the quality of life of the person. As an example, extract of silybum marianum and licorice are sold for their HCV related effects; the first is said to provide some generic help to hepatic functions, and the second to have a mild antiviral effect and to raise blood pressure.
There are new drugs under development like the protease inhibitor BILN 2061 that look promising but are all in early phase of developement (http://www.ismc2004.dk/index.php/Session_2A__The_discovery_of_B/258/0/). All of these are not approved remedies and have not yet demonstrated their efficacy in clinical trials.
10,000-20,000 deaths a year in the United States are from HCV; expectations are that this will increase, as those who were infected by transfusion before HCV test will become apparent.
- Viral Hepatitis C Frequently Asked Questions - cdc.gov (http://www.cdc.gov/ncidod/diseases/hepatitis/c/faq.htm)
- National Hepatitis C Prison Coalition (http://www.hcvinprison.org/)
- Hepatitis C Support Project (http://www.hcvadvocate.org/)
- online hepatitis C encyclopedia (http://www.hepatitis-central.com/index.html)
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