Hepatitis A

Hepatitis A

    * Introduction
    * Signs and symptoms
    * Diagnosis
    * Treatment
Hepatitis is a general term that describes inflammation of the liver and can be caused by many viruses such as HAV, HBV, HCV, HVD, hve, HVF. Hepatitis A is one of the oldest known diseases of the human species, is a self-limited disease that causes fulminant hepatitis and death only a low percentage of people. But is it a significant cause of morbidity and socio-economic losses in many parts of the world. Predominant route of transmission is fecal-oral infection occurs in young people, in areas where hygiene and living conditions are poor. Under these conditions, epidemics can break out of a single source of fecal contamination. Infection is caused by hepatitis A, non-enveloped infectious unit, type RNA of the genus hepatovirus, picornavirus family. Interfere with the liver infection, while replicate in hepatocytes. Activated immune system produces specific Action to eradicate the virus, as a consequence of pathological destruction, the liver becomes inflamed. People succeptibile to infection are those who have not contracted the infection never in history and the unvaccinated. The risk of infection depends on virus resistance in the environment, poor hygiene in large parts of the world, and his survival in human excrement. In areas where hepatitis A is endemic, most infections occur in childhood. Evolution of hepatitis A can be highly variable. Patients with subclinical forms inaparente or no symptoms and shows no jaundice. In general, children belong to this group. There are asymptomatic cases can be detected only by biochemical and serological tests. Patients may develop hepatitis or jaundice as BVH, stages and symptoms of mild to severe and prolonged, after which they can recover completely or develop fulminant hepatitis. The most common symptoms are: fatigue, stomach pain, nausea, vomiting, anorexia, weight loss, right upper quadrant pain, fever, muscle cramps. Maybe skin jaundice, the whites, mucous membranes and dark urine. There is no causal treatment of hepatitis A, but only one supportive. Hepatitis A is a viral disease, so antibiotics have no effect given. Antiviral agents, corticosteroids can not control the disease. Administration of immunoglobulin improves symptoms within the first two weeks of onset, but have no effect if you installed acute hepatitis. Only supportive therapy can be, full recovery occurs in 90%.
Pathogenesis Hepatitis A is an enterovirus, liniear RNA, single-stranded, positive sense, a member of the family Picornaviridae. In humans, viral replication and protein synthesis dependent internalization in hepatocytes. Assembly takes place only in liver cells. Contracting the virus is almost exclusively about digestive, through fecal-oral transmission, although there were isolated cases of parenteral transmission. Icohexaedric virus without envelope and measures 28 nm in diameter. It is characterized by resistance to distortion through the ether, acid, and drying temperatures of 56 degrees Celsius and -20 degrees Celsius. Hepatitis A virus can remain viable for a very long time. Boiling and chlorination of drinking water are effective methods of destruction. There are many genotypes of the virus, but only one serotype. Virion internealizeaza hepatocytes after hosing to a specific receptor and is then decoded the viral RNA and binds to host cell ribosomii polisomii viral. They synthesize viral proteins and viral genome is copied by RNA polymerase. Viral particles are assembled and sent tree bile excreted in feces. It has been demonstrated and virus transmission by blood, severe infectious period is during the prodrome BVH, 14-21 days after infection. The incubation period lasts 2-6 weeks and the time to onset of symptoms is correlated with the infecting dose. Severity of symptoms is determined so old host. In developing countries, the age of acquisition is 2 years in industrialized countries, age is 5-17 years.
Causes E tiologia contracting hepatitis A is caused by hepatitis A virus, the predominant way fecal0orala, but also through blood products. Risk factors involved in contracting the infection are: -Travel in endemic areas -Or bisexual persons hemosexuale Illicit drug-use injections or injectable -People with hemophilia, or who have received blood transfusions of blood or concentrates -Consumption of raw seafood Poor hygiene and hands-on how food preparation.