Hepatitis is a gastroenterological disease, featuring inflammation of the liver. The clinical signs and prognosis, as well as the therapy, depend on the cause. more...
Signs and symptoms
Hepatitis is characterised by fatigue, malaise, joint aches, abdominal pain, vomiting 2-3 times per day for the first 5 days, loss of appetite, dark urine, fever, hepatomegaly (enlarged liver) and jaundice (icterus). Some chronic forms of hepatitis show very few of these signs and only present when the longstanding inflammation has led to the replacement of liver cells by connective tissue; the result is cirrhosis. Certain liver function tests can also indicate hepatitis.
Types of hepatitis
Most cases of acute hepatitis are due to viral infections:
- Hepatitis A
- Hepatitis B
- Hepatitis C
- D-agent (requires presence of the hepatitis B virus)
- Hepatitis E
- Hepatitis F (discredited)
- Hepatitis G
- Please see the respective articles for more detailed information.
- See also infectious canine hepatitis.
Hepatitis A is an enterovirus transmitted by the orofecal route, 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 usually advised to rest, stay hydrated and avoid alcohol. A vaccine is available that will prevent infection from hepatitis A for life. It can be spread through personal contact,consumption of raw sea food or drinking contaminated water.
Hepatitis B causes both acute and chronic hepatitis in some patients who are unable to eliminate the virus. Identified methods of transmission include blood (blood transfusion, now rare), tattoos (both amateur and professionally done), horizontally (sexually or through contact with blood or bodily fluids), or vertically (from mother to her unborn child). 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 programmes 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 (mainly South-East Asian) countries, 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. In about 45% of persons on treatment achieve a sustained response.
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