Hepatitis A or infectious jaundice is caused by a picornavirus and is transmitted by the orofecal route through food contaminated by unwashed hands. It causes an acute hepatitis and does not have a chronic stage. The patient’s immune system makes antibodies against hepatitis A and this confers 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 contaminated drinking 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 people excrete the hepatitis A virus in their stool two weeks before and one week after the appearance of jaundice. 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 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, sexually (through sexual intercourse or through contact with blood or bodily fluids), and in utero (from mother to her unborn child, as the virus can cross the placenta). However, in 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 of infected persons. Needle-exchange programs have been created in many countries as a form of prevention. In the United States, 95% of patients ultimately clear their infection and develop antibodies against the hepatitis B virus. 5% of patients do not clear the infection and develop chronic infection. These 5% 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 Southeast Asian) countries, making cirrhosis and hepatocellular carcinoma the big killers. There are six FDA-approved treatment options available for persons with a chronic hepatitis B infection: alpha-interferon, pegylated interferon adefovir, entecavir, telbivudine and lamivudine. About 45% of persons on treatment achieve a sustained response.
Hepatitis C (HCV) (originally named “non-A non-B hepatitis”) is caused by a Flavivirus. It can be transmitted through contact with blood (including through sexual contact where the two parties’ blood is mixed). Hepatitis C may lead to a chronic form of hepatitis, culminating in cirrhosis. It can remain asymptomatic for 10-20 years. Patients with hepatitis C are prone to severe hepatitis if they contract either hepatitis A or B, so all hepatitis C patients should be immunized against hepatitis A and hepatitis B if they are not already immune. The virus can cause cirrhosis of the liver. HCV viral levels can be reduced to undetectable levels by a combination of interferon and the antiviral drug ribavirin. The genotype of the virus determines the rate of response to this treatment regimen. Genotype 1 is more resistant to interferon therapy than other HCV genotypes.
Symptoms of Hepatitis
The symptoms of all three forms of vital hepatitis are similar, although they may vary in intensity and surely in duration. They are: a short mild flu-like illness, nausea and vomiting, diarrhea, loss of appetite, weight loss, jaundice (yellow skin and whites of eyes, darker yellow urine and pale feces), and itchy skin.