Resumo de Eran

Hepatitis A
Hepatitis A or infectious jaundice is caused by a picornavirus. It is transmitted by the orofecal route, transmitted to humans through methods such as contaminated food. It causes an acute form of hepatitis and does not have a chronic stage. The patient''s immune system makes antibodies against hepatitis A that confer immunity against future infection. People with hepatitis A are advised to rest, stay hydrated and avoid alcohol. A vaccine is available that will prevent infection from hepatitis A for life. Hepatitis A can be spread through personal contact, consumption of raw sea food or drinking contaminated water. This occurs primarily in third world countries. Strict personal hygiene and the avoidance of raw and unpeeled foods can help prevent an infection. Infected persons already begin excreting the hepatitis A virus with their stool two weeks after the appearance of the first symptoms. The time between the infection and the start of the illness can run from 15 to 45 days, and approximately 15% of sufferers may experience relapsing symptoms from six months to a year following initial diagnosis.

Hepatitis B
Hepatitis B is caused by a hepadnavirus, which can cause both acute and chronic hepatitis. Chronic hepatitis develops in the 15% of patients who are unable to eliminate the virus after an initial infection. Identified methods of transmission include blood (blood transfusion, now rare), tattoos (both amateur and professionally done), sexually (through sexual intercourse or through contact with blood or bodily fluids), or in utero (from mother to her unborn child, as the virus can cross the placenta). However, in about half of cases the source of infection cannot be determined. Blood contact can occur by sharing syringes in intravenous drug use, shaving accessories such as razor blades, or touching wounds on infected persons. Needle-exchange programs have been created in many countries as a form of prevention. In the United States, 95% of patients clear their infection and develop antibodies against hepatitis B virus. 5% of patients do not clear the infection and develop chronic infection; only these people are at risk of long term complications of hepatitis B.

Patients with chronic hepatitis B have antibodies against hepatitis B, but these antibodies are not enough to clear the infection that establishes itself in the DNA of the affected liver cells. The continued production of virus combined with antibodies is a likely cause of immune complex disease seen in these patients. A vaccine is available that will prevent infection from hepatitis B for life. Hepatitis B infections result in 500,000 to 1,200,000 deaths per year worldwide due to the complications of chronic hepatitis, cirrhosis, and hepatocellular carcinoma. Hepatitis B is endemic in a number of countries (mainly South-East Asian), making cirrhosis and hepatocellular carcinoma big killers. There are three FDA-approved treatment options available for persons with a chronic hepatitis B infection: alpha-interferon, adefovir and lamivudine. About 45% of persons on treatment achieve a sustained response.

Hepatitis C

Resumos Relacionados