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Types Of Hepatitis
By peace | November 26, 2006
Hepatitis is a gastroenterological disease, featuring inflammation of the liver which can be caused by at least three different viruses. The progress of the disease follows a similar pattern in all three viruses.
The word hepatitis simply means an inflammation of the liver without pinpointing a specific cause. Someone with hepatitis may:
- have one of several disorders, including viral or bacterial infection of the liver
- have a liver injury caused by a toxin (poison)
- have liver damage caused by interruption of the organ’s normal blood supply
- be experiencing an attack by his or her own immune system through an autoimmune disorder
- have experienced trauma to the abdomen in the area of the liver
Hepatitis is most commonly caused by one of three viruses:
- hepatitis A virus
- hepatitis B virus
- hepatitis C virus
In some rare cases, the Epstein Barr Virus (which causes mononucleosis) can also result in hepatitis because it can cause inflammation of the liver. Other viruses and bacteria that also can cause hepatitis include hepatitis D and E, varicella (chickenpox), and cytomegalovirus (CMV).
Hepatitis A or infectious jaundice is an Hepatovirus (originally thought to be an enterovirus) transmitted by the orofecal route, transmitted to humans through methods such as contaminated food. Hepatitis A has an incubation period of 14-42 days, and is most common in children and young adults. The virus is found in the patients’s faeces and is transmitted by contaminated food or water. 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. Isolated cases are usually due to person-to-person contact, but epidmics are generally caused by flies spreading infection.
Hepatitis B 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 intercouse 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.
Hepatitis B has an incubation period of six to 26 weeks and it can occur at any age. The virus has an antigen, called Australia Antigen, on its surface, and this can be detected in the bloodstream. The antigen causes the formation of a special antibody which remains in the blood.
The virus may stay in the blood for months, possibly for life, and for this reason, people with B virus cannot give blood for transfusions and are a risk to dentists, doctors and nurses, as well as laboratory staff who may handle blood samples.
Virus B hepatitis is also known as serum hepatitis because it used to be spread by transfusions and injections given with incompletely sterilised needles and syringes. With modern tests and disposable syringes and needles, the risks to most people are now extremely low. Outbreaks occasionally occur in hospitals, particularly among drug addicts who share or use contaminated syringes and, as carriers, are very dangerous to medical staff.
Spread can also occur from swallowing, from splashes in the eye and from sexual(including homosexual) intercourse.
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.
Hepatitis C (originally “non-A non-B hepatitis”) can be transmitted through contact with blood (including through sexual contact where the two parts blood is mixed). Hepatitis C may lead to a chronic form of hepatitis, culminating in cirrhosis. It can remain asymptomatic for 10-20 years. No vaccine is available for hepatitis C. 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. However, hepatitis C itself is a very lethal virus and can cause cirrhosis of the liver. The virus, if detected early on can be treated by a combination of interferon and the antiviral drug ribavirin. The genotype of the virus determines the rate of response to this treatment regimen.
Hepatitis E produces symptoms similar to hepatitis A, although it can take a fulminant course in some patients, particularly pregnant women; it is more prevalent in the Indian subcontinent.
Hepatitis G has been identified and is probably spread by blood and sexual contact. There is, however, doubt about whether it causes hepatitis, or is just associated with hepatitis, as it does not appear to be primarily replicated in the liver.
Other viruses can cause infectious hepatitis:
* Mumps virus
* Rubella virus
* Cytomegalovirus
* Epstein-Barr virus
* Other herpes viruses
