The viral hepatites gather the infections caused by Virus developing at the expense of hepatic fabric. The viruses, once inoculated at the organization, then infect preferentially the cells of the liver also called Hépatocyte S (in opposition to the hepatic attack - inconstant - secondary with other viral diseases like the infectious Mononucléose or the Herpès for example). The infected cells are seen then obliged to take part in the viral Métabolisme , namely to manufacture without end of the copies of the virus in question. The Hépatocyte, inflated by a not controlled production of virus, ends up exploding, thus characterizing the Cytolyse Hépatique, with the usual disturbances of hepatic assessment.

Although hepatitises has, B and C have similar names (because they cause all three of the damage to the liver) the viruses are quite different.

The five following viral hepatites are described:

Virus of hepatitis has

The virus of hepatitis has (VHA) is a virus with ARN pertaining to the family of the Picornaviridae, added in December 2005 to the list of the Infectious illness to obligatory declaration into force in France. It is a naked virus (not wrapped), therefore very resistant in the medium external and with the physico aggressions - chemical.

Duration of incubation

4 to 6 weeks

Mode of contamination

By indirect way: by soiled water, contaminated by saddles infected by the virus, or direct way: oro-fecal manu carried.

Private clinic

This virus causes a epidemic Hépatite. However the hepatic lesions (hépatolyse) are not due to the virus directly but to the lymphocytes T which will destroy the infected cells of the liver.

Hepatitis has can remain asymptomatic in more half of the cases. In the other cases, it appears by a Syndrome grippal (nauseas, vomiting, anorexia, headaches, feverish state), or by nausea S, Vomissement S, Arthralgie S, Myalgie S, a rash, abdominal pains, a Ictère, a Prurit, a Splénomégalie, Adénopathie S. These symptoms can last for two months.

Diagnosis

There are a rise of transaminases and Immunoglobulins M (IgM) anti VHA as of the 25e day.

Epidemiology

The monitoring of the evolution of the incidence in France is carried out by the Réseau Sentinels of the Inserm, like by an obligatory declaration since 2005. Its distribution varies according to the socio-economic conditions. The Prévalence is inversely proportional to the context socio-economic and proportional to the age: the more the standard of living is raised, the less there are infected people. The older people are, the more there is case. One attended a strong fall of the Prévalence at the young subjects, which is rare. It is due to the improvements of the conditions of hygiene.

Prevention

There exist three means:

• hygiene: very important, it is necessary to wash the hands after being gone with the toilets, and before making eat or eating.
• the Serotherapy: one gives gamma globulines general-purpose. It is effective only up to two weeks after the supposed date of the contamination. Vaccination is indicated in the case of voyages in endemic zone. It consistitue also an alternative to immunoglobulins when the date of contamination is close.

Hepatitis, declared once, does not have specific treatment.

Bonds

• INVS: update of the list of the notifiable diseases
• INVS: card-index Hépatite has

Virus of hepatitis B

The virus of hepatitis B (VHB) is a virus with DNA pertaining to the family of the Hepadnaviridae. The principal symptoms are a Ictère (jaundice), a fever and a prolonged tiredness. The virus is very resistant, it is strongly contagious, 100 times more than that of the AIDS. According to the the World Health Organization there would be 350 million carriers of the virus in the world. In the blood of a patient in active phase of viral synthesis, one can observe 3 types of structure:

1. of the spheres of 20nm of diameter,
2. of the tubules of 20nm of diameter and 200 with 700nm length which is a stacking of the spheres,
3. particles of Dane of 42nm of diameter, corresponding to the whole viral particles, made up of a core (nucléocapside containing a DNA doubles bit associated with ADNpol) as well as envelope.

The particles of Dane represent the complete virus whereas the spheres and the tubules only correspond to the envelope of this last.

Duration of incubation

The incubation period is normally from 45 to 180 days, but the average is from 60 to 90 days. All this can increase or decrease according to the gravity of the infection of the virus of the type B.

Mode of contamination

• transmission by transfusions of blood or blood products: rare since the exclusion of the AgHBs donors + and anti-HBc ac +.
• Iatrogenic transmission by material not sterilized (surgery, invasive exploration, dental acupuncture, mésothérapie, care): The evolution of the rules of sterilization and the generalization of the use of material of single use make it possible to avoid it.
• accidental puncture
• transmission by intravenous Drug-addiction , tattooing, Piercing.
• transmission by interindividual heterosexual, homosexual contact or not sexual: interest of the use of condoms.
• vertical transmission at the time of the period néonatale: the tracking of Ag HBs during the pregnancy allows the serovaccination of the newborn (in the first 48 hours).

Evolution

The virus of hepatitis B cures spontaneously in 90  % of the cases. In 1  % of the cases occurs a fulminant hepatitis. 10  % of the patients see their hepatitis B evolving/moving in chronic form (90% at let us nourissons). These chronic forms can cause lesions of Cirrhose, leading to the cancer hépatocellulaire (15% to 25% of the chronic carriers die of the complications by cirrhosis or cancer of the liver).

Until the end of the 20th century, the rate of cure was of 30  % (to be checked, META reference) with very heavy treatments (Interféron). This disease annually caused more than one million premature deaths.

Certain patients carrying the virus do not present a hepatic attack; they are called healthy carriers.

Treatment

curative Treatment:
Its objective is to prevent the evolution towards the cirrhosis and cancer, at the patient having chronic hepatitis B with viral replication and histological hepatic lesions. Its evaluation rests on biological criteria (Ag HBe, viral DNA, ac antiHBe) and histologiques
The antiviral treatment of first intention is the peginterféron esparto-2a during 24 to 48 weeks, which with the advantage of only one weekly injection instead of 3 for the interféron esparto . The profile of undesirable effects is similar for these two products. Remainder the effectiveness of the peginterféron esparto-2a is comparable with that of the interféron esparto which involves a prolonged disappearance of AgHBe in 20 to 40% of the cas.
The other antiviral ones are used in second intention: to adéfovir dipivoxil and Lamivudine when the head end is insufficiently effective or because of its undesirable effects. The to entécavir is currently used in third intention. The other antiviral ones are in the course of evaluation: the emtricitabine , the to ténofovir , the telbivudine , the clévudine .
In the event of décompensée hepatic attack, the hepatic Transplantation is the only effective cure in a durable way.

Treatment préventif'
Vaccination: First human vaccine obtained by genetic Engineering starting from animal cells. This vaccine was developed by the team of Pierre Tiollais in 1985.

At the newborn of positive mother Ag Hbs: Immunoglobulins specific and vaccination to the birth. In this protocol, the reduction of the transmission risk to the child is of 92%.

Virus of hepatitis C

The Virus of hepatitis C (VHC) is a Virus with ARN simple bit of positive polarity of approximately: 9600 bases. It belongs to Flaviviridae and is the only one representing hepacivirus kind. Before its discovery by molecular biology in 1989, it was called hepatitis “non-A-non-B”. It is about a virus wrapped (the envelope comes from the host cell) and its capsid is icosahedral of cubic symmetry. The viral nucleic acid has

1. stucturaux genes (C, protein of core; E, glycoprotéine of envelope)
2. of nonstructural genes (NS1 with NS5)

See also: Hepatitis C

Symptoms

In the majority of the cases, the infected people in a recent way by the VHC do not have any symptom. The incubation of the virus takes on average two months, the acute phase of the hard disease as for it from two to twelve weeks. The spontaneous cure occurs in approximately 25  % of the cases. However, in the majority of the cases, the disease becomes chronic: the virus, highly mutagen, manages to escape the immunizing response. When the acute phase of the infection is symptomatic (ictère), the passage to chronicity is less frequent. The healthy cells of the liver are able to be renewed but the destruction of the infected cells leaves scars. The accumulation of these scars during time, over years even of tens of years, leads to a “Fibrose” of the liver. This damage with the liver can develop at the end of ten to forty years of infection. It can then cause damage with the liver in the long run, going in certain cases until the Cirrhose or the Cancer.

The most current symptoms are tiredness, the loss of appetite, nauseas, of the fever, a general weakness and abdominal pains.

Transmission

Contrary to hepatitis B, the virus of hepatitis C is not regarded as a Sexually transmitted disease. The mode of contamination is the blood way. The majority of the transmissions were thus noted by use of intravenous Drogue (exchange of syringe) or by blood transfusion (before systematic tracking in 1992 of the VHC in the blood donors). The use of condoms between stable partners is not essential, but it is recommended in the event of lesions, of genital infections or reports/ratios during the rules. The protected reports/ratios are also recommended in the event of multiple partners. The contact with infected blood is possible in other circumstances: any puncture or contact of a wound, even tiny, with an infected instrument can transmit the virus (tattooing, piercing, sniff, division of the small equipment of injection other than the syringe…)

The other precautions to take to avoid the contamination of its entourage consist in protecting the wounds and cuts immediately after disinfection, to avoid the division of objects in contact with blood (certain toilet requisites like the Coupe-ongles, the razor, the tweezers, brushes with tooth…). The transmission risk under these conditions is then very weak.

Epidemiology

It is estimated that the VHC infects approximately 170 million people in the world. The coïnfection with virus HIV is very frequent.

There exist now reliable tests to detect the virus in blood. In complement, a PCR can be used to detail the genotype of the virus. One subdivides the virus in groups and localization. For example, the genotype 1a is most widespread in North America while the 1b is in Europe.

Contrary to the viruses of hepatitises has and B, there does not exist vaccine against the VHC.

Treatment

The treatments against the VHC are based on the Interféron alpha (IFNα), associated with the other antiviral ones. At present, the treatment more prescribed is the pegylé interféron accompanied by Ribavirine. Aujourd today in phase of test one combines also a new inhibiter of the protease of hepatitis C, the SCH 503034. The SCH 503034 showed a potential of antiviral activity and was well tolerated, as well in a monothérapie (1) as in partnership with the PEGINTRON (R) and accompanied by Ribavirine. The results vary according to the genotype of the virus with until 75  % of chance of disappearance of the virus of the organization. There exist 6 principal genotypes, 1 2 3 4 5 6, genotypes 2 and 3 are thus those which resist the treatment less.

The alcohol is strongly disadvised in the event of VHC because of a stressing of the damage to the liver and a reduction in the effectiveness of the interféron.

The side effects of these treatments are important but enormously vary from one individual to another (of the simple symptom grippal, with the tiredness generalized until attacks with the immune system,…). The most frequent effects are the reduction in the number of white globules, plate, and the globules red, the depression, the thyroid attack. Only being able to persist after the stop of the treatment is the thyroid attack requiring the thyroid catch of hormones.

Ribavirin is teratogenic in the animal. At the man as at the woman, the design of a child must await the clearance of ribavirin, which is obtained 6 months after the end of the treatment.

There to date does not exist vaccine and this because of the great antigenic variability of the virus.

Factor delta: agent of hepatitis D

The agent of hepatitis D is a defective virus with ARN i.e. depend on the virus B for its replication and its expression. The agent delta occurs by coïnfection with the VHB or then by superinfection of a carrier of the VHB. In the Western countries, the agent delta is acquired by use of drugs. There exist endemic areas in particular in Africa. The agent delta, while decreasing the replication of the VHB, worsens considerably the hepatic disease with fulminant forms and in a way much more frequent one acceleration of the hepatic fibrosis and which has occurred of cirrhoses and carcinome hépatocellulaire. The detection of the ARN delta makes it possible to detect the active infections

Hepatitis D is to some extent a superinfection of hepatitis B.

See also: Hepatitis D

Duration of incubation

Hepatitis delta does not make that to increment the destroying effect of hepatitis B. Its time of incubation is thus the same one as that of the virus on which it depends.

Mode of contamination

The Delta factor is transmitted same manner as hepatitis B, by puncture, transfusion, tattooing, piercing and sexual contact not protected. Carriers of hepatitis B as well as the people suffering from fulminant hepatitis sound particularly sensitive to the factor delta.

Virus of hepatitis E

Hepatitis E is a virus ARN (like hepatitis C and A) but is especially present in the countries in the process of development.

About fifty case however was listed in France.

As for hepatitis has, the contamination is done by oro-fecal way.

See also: Hepatitis E

See too

See also the general article on the Hepatitis S

External bonds

• Rhévir Site, of the Biological Course Study of the Viral hepatites in Languedoc Roussillon, in particular animated by virologists of the CHU of Montpellier
• Site of association Network Vaccine Hepatitis B
• Article on Co-infection HIV and hepatitis B and C published in the “weekly Bulletin epideliologic” n°25 of June 17th, 2005
• Article the virus of hepatitis C published to daN “the General practitioner” n°2084 of January 16th, 2001
• hepatitises: information general public and discussion forums

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