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Wednesday, November 16, 2011

Hepatitis C

Hepatitis C is an infectious disease caused by the Hepatitis C virus (HCV), which is a RNA virus. This virus is characterized by an intensive mutations, so, at every infected person, the virus exists as a population of very close, but different virus quasi-species, and some of them are more successful than the others.
The dominant virus sequence changes every few weeks. This changes helps the virus to skip the immune response of the host. The infection varies in different countries, but also in different regions and population groups within one country. It is considered that around 170 million people are already infected with HCV, and every year there are 3-4 millions new infected. HCV is transmitted almost strictly through contact with an infected blood or blood products, same as the HBV (Hepatitis B virus) and HIV, with the difference that this virus is very hard to transmit through the other types of contact, although it is present in the saliva and the sperm.
Because of the parenteral way of transmission (most often: blood transfusion, drug addiction, contacts with a material contaminated with infected blood), hepatitis C is very common among the hemodialisis patients, hemophilia patients, the intravenous drug users (50-90%). There’s a risk also by nasal insufflation of cocaine (sniffing). From the other ways of transmission, there’s need to be mentioned the transmission from the mother to the newborn baby (less than 5%), the sexual transmission, which is possible, but not as often as with HBV and HIV, then the incidental injuries with needles or other instruments of the health personal (3-10%).
Additionally there are other identified ways of transmission, such as using poorly sterilized materials or instruments in endoscopy, piercing, tattooing, acupuncture, etc. There is no effective vaccine for the HCV infection, so the prevention has to consist of the basic safety measurements as of HBV and HIV.
The acute phase of the Hepatitis C is the first stage of the infection and can last even longer than 6 months. Only 30-40% of the patients with an acute HCV infection have some symptoms. Those are usually mild and few symptoms, such as weakness, and in 90% of the cases there isn’t a jaundice, and that’s why in many cases the patients aren’t even aware of the infection.
The acute phase in 15-20% of the cases result in healing and complete elimination of the virus. But, in 80-85% the acute HCV infection progresses to a chronic hepatitis. Although 15-25% of the patients with chronic hepatitis C have no obvious symptoms, the rest of the patients develop chronic active hepatitis, and 20% of them develop cirrhosis within 10-20 years.
The chronic hepatitis C can be accompanied by many autoimmune manifestations such as vasculitis, Sjogren’s syndrome, autoimmune hepatitis C type 2, Hashimoto’s thyroiditis, lychen planus, etc. Because there are no obvious symptoms, the diagnosis is most often coincidental. The treatment consists of combination of interferon alfa and ribavirin.

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