Hepatitus

Hepatitis B Virus

Hepatitis B virus (HBV), formerly called serum hepatitis, is much more prevalent than HIV ( the virus that causes AIDS). An estimated 1.2 million Americans are currently chronic carriers of HBV, with more than 300 million carriers in the world. Hepatitis B may develop into a chronic disease (lasting more than 6 months) in up to 10% of the newly infected people each year. If left untreated, the risk of developing cirrhosis (scarring of the liver) and liver cancer is greatly increased.

This disease is much more infectious than HIV. It is transmitted through infected blood and other body fluids (seminal fluid, vaginal secretions, breast milk, tears, saliva and open sores). In the U.S., hepatitis B is spread predominantly through sexual contact. Other risk groups include health care workers, prison inmates and personnel, IV drug users, and recipients of blood transfusions prior to 1975. In families, it appears that the virus can be casually spread from adults to children.

The onset of hepatitis B is gradual. As with other forms of hepatitis, most people who get hepatitis B have no recognizable signs or symptoms. But some people do experience flu- like symptoms, such as loss of appetite, nausea and vomiting, fever, weakness, tiredness, as well as mild abdominal pain. Less common symptoms are dark urine

Hepatitis B virus

and yellowing of the skin and eyes (jaundice). The only way these diseases can be positively identified is through blood tests. However, over 90 to 95 percent of adult patients recover within six months, while 5 to 10 percent develop chronic hepatitis or become carriers. Severe manifestations of chronic HBV infection include development of scarring of the liver (cirrhosis), and liver cancer which usually occurs decades later.

An HBV carrier is someone who has had hepatitis B in their blood for more than six months. A carrier usually has no signs or symptoms of HBV but remains infected with the virus for years or for a lifetime and is capable of passing the disease on to others. Two types of vaccine are available to prevent hepatitis B.

Hepatitis D Virus

Infection with hepatitis D (HDV)

occurs only in patients already infected with hepatitis B. Hepatitis D is spread mainly by contaminated needles and blood. I.V. drug users have a high incidence. The simultaneous infection with HBV and HDV produces more severe illness, and higher rates of long term liver failure, than HBV alone. The disease is usually self-limited, and due to its co-dependence on HBV, hepatitis D is effectively prevented via the HBV vaccine.

Hepatitis G

A newly identified strain of hepatitis, hepatitis G is currently under study. The first major study of virus has reported that those infected by means other than blood transfusions did not develop chronic liver disease, although for most the virus remained in their blood for several years. It is not clear at this time how widespread hepatitis G is, what the means of transmission are, or what its precise effects are on infected patients.

Other Hepatitis Viruses

There is accumulating evidence that other hepatitis viruses exist - in part due to the fact that the known viruses (A through G) do not explain all cases of hepatitis that are believed to be caused by viruses. Detailed studies are currently underway. However, the clinical significance and public health impact of other hepatitis viruses remains unknown.