Hepatitis C is characterized by inflammation of the liver. It is caused by a virus: the hepatitis C virus (HCV HCV or in English).
The hepatitis C virus was discovered in 1989 by teams of Michael Houghton and Daniel W. Bradley. It is the agent of viral hepatitis which until then were labelled "non-A non hepatitis B". It was classified in the family Flaviviridae, which consists of three types:
* Flavivirus, responsible for arboviruses
* Pestiviruses, which have only diseases in animals
* Different genotypes of HCV (hepatitis C) that make up the kind of Hepacivirus
It is a small virus about 60 nm in diameter, its RNA genome is a single-polarity positive linear content in a capsid protein icosaèdrique.
Its transmission is parenteral ie it is transmitted through blood. Two major modes of contamination exist: contamination transfusion secondary to transfusions carried out before 1992 (which is the date when the vials of blood were systematically subjected to testing sensitive) and injecting drug use (exchange) or nasally (straws used may be soiled with blood), tattoos and piercings. Unlike hepatitis B, hepatitis C is not transmitted through sexual contact (less than 5%) and little transmitted from mother to child at birth (less than 10%). However, the latter two modes of contamination are directly proportional to the viremia (amount of virus circulating).
Next regions, its prevalence varies from 0.5% to 6% of the population (1% in France, 2% in Japan). The seroprevalence of hepatitis C among children and adolescents is 0.2 to 0.4%.
* The diagnosis of hepatitis C requires the identification of anti-HCV by a screening test. If this test is negative, the subject has never been in contact with the virus. If the screening test is positive, it must be checked on a second blood sample and use another technique for detecting antibodies. When both tests are positive, the subject has been in contact with the virus and has antibodies that are unfortunately not protectors against a possible new infection.
* For subjects with two testing positive (or tests discordant), conducts research on the viral RNA in the blood of the topic. If this research is positive, the subject is infected with the virus. If this research is negative, he eliminate the virus (spontaneous healing) and is no longer infected. The latter represents only 15 to 20% of subjects. The majority of subjects remain chronically infected with the virus (lack of healing after 6 months).
* In cases of suspected hepatitis C recent (less than 3 months), a search for viral RNA can be achieved.
* The biomarkers followed to monitor the effectiveness of treatment are transaminases (ALAT) and quantification of viral RNA blood or HCV viral load. The goal is healing with a viral load undetectable HCV 6 months after stopping treatment.
* The genotyping of the virus is most often directed by sequencing (or hybridization) a region of the viral genome.
HCV is a big family, RNA virus has a variety of genome quite important. There are six major genotypes, noted 1 to 6, and many subtypes. These genotypes do not provide evolution of hepatitis significantly different. They against importance in the response to treatment. Genotypes 2 and 3 are better than 1 in order shown, and certainly better than the 4. That is why the treatment of genotypes 2 and 3 lasts only 24 weeks when he was 48 weeks for 1. For 4, it was less decline because of its recent appearance in France and in Europe.
The virus can remain several years in a latent state. The patient is then called a "healthy carrier", ie he has no symptoms but can transmit the disease. The danger is that many patients are infected with the virus without knowing it, and therefore can contaminate their loved ones. Hence the importance of screening in case of risk.
When the disease becomes manifest, it can have several consequences: cirrhosis (chronic liver). The virus also promotes liver cancer (10%).
The treatment begins with an activity (necrosis and inflammation) minimal, and a moderate fibrosis, or A1F2 on the Metavir score. It is supported 100% by social security. The cost in 2002 was 250 000 francs, or 38 112 € uros today.
Side effects are numerous, vary depending on individuals, but disappear at the end of treatment. In most cases, the patient must cease all activity because of these effects: work, sports, ...
* Interferon: The injection of interferon causes flu-like symptoms: high fever, aches and headache. Other symptoms include fatigue, insomnia, hair loss, dry skin. A character disorder and a disorder of the thyroid gland may also occur.
* Ribavirin: The main side effect is anaemia: shortness of breath, rapid heart, fatigue ...
The combination of these two drugs cause side effects listed above, but these effects are more frequent.
These side effects bring other complications:
* Dry skin: Dehydration, with desire to drink continuously. Eruptions skin of all sizes and all kinds all over his body. Conjunctivitis caused by the lack of protection of the eye (tears).
* The nature of the disorder can lead to depression with envy suicide.
The insomnia, added to the fatigue leads a state of exhaustion. Example: the simple act of dressing in the morning requires a recovery time.
Read also Hepatitis A, Hepatitis B