VIRAL HEPATITIS

Background

Hepatitis was the first documented transfusion-transmitted disease. Many of the current practices for diminishing risk in transfusion medicine are based on the experiences of controlling the transmission of hepatitis.

Hepatitis viruses, which affect the liver, fall primarily into two groups: viruses that cause acute disease and are not often transmitted by transfusion (hepatitis A and E), and viruses with a chronic course that can readily be transmitted by blood transfusion (hepatitis B and C).

Hepatitis A Virus (HAV)

Hepatitis A (HAV) infection is rarely transmitted through blood transfusion; it is usually spread by contaminated food and water.

Like HAV, hepatitis E virus is a food and water borne form of hepatitis resulting in outbreaks.

Hepatitis B Virus (HBV)

HBV is a major cause of acute and chronic hepatitis. There is a large number of people die each year from hepatitis B-related cirrhosis, and many die from hepatitis B-related liver cancer.

Hepatitis C Virus (HCV)

Acute hepatitis C virus (HCV) is relatively mild. It has an incubation period of about seven to eight weeks. However, post transfusion infection with HCV most often becomes chronic. The majority of people with chronic HCV infection may be asymptomatic.

Hepatitis G Virus (HGV)

A new virus, provisionally designated hepatitis G virus (HGV), was described in 1996. Although the virus may be transmitted through transfusion, the association of HGV infection with liver disease remains unresolved. The majority of people who carry the virus appear to have no liver abnormalities. The absence of significant liver disease suggests that transmission of the virus may not greatly undermine the safety of the blood supply.

Other Hepatitis Viruses

There are hepatitis viruses which are being researched by the blood banking community. One of these, Hepatitis D virus (HDV), causes infection only in the presence of HBV. Individuals who are infected with both HBV and HDV are at a much more serious risk for disease progression. However, testing to detect the presence of hepatitis B should prevent these.