The severity and course of hepatitis B infections depends upon several factors,
including the initial dose of virus, immunocompetency of the host, and overall
health of the individual prior to infection.
The most frequent response is an asymptomatic infection. In this case, the
patient's symptoms are so mild that the patient is unaware of the infection or
considers the illness as minor. Anti-HBs and anti-HBc levels are detectable and
lasting immunity results.
The period of acute infection usually lasts one to six months. The symptoms may
be mild to quite severe. The infection is considered resolved with the production
The classic definition of chronic hepatitis is a person who exhibits HBsAg positivity
and/or elevated liver enzymes for more than six months. It can last as little as one
year or as long as several decades. Chronic HBV can be mild or quite severe.
Two classifications of chronic hepatitis B exist: chronic persistent hepatitis (CPH)
and chronic active hepatitis (CAH).
One to three percent of acute HBV infections progress to the stage of fulminant
infection. The diagnosis of fulminant hepatitis is reserved for patients with signs
and symptoms of liver failure during the course of acute hepatitis. Serum bilirubin
and liver enzymes are extremely high and immunological markers are similar to
those in typical acute hepatitis. Death usually results from the destruction of at
least 90% of the body's liver.
Little is known as to the true structure and classification of the hepatitis D virus. It
is thought to be a single-stranded RNA virus and is considered to be a defective
agent since it requires the presence of HBsAg in order to replicate. (para 7-23)
HDV is transmissible via the parenteral route. Persons with frequent and repeated
blood exposures (drug addicts, hemophiliacs, multiple blood transfusions,and so forth)
appear to be at higher risk for contacting this virus. Since HDV requires the
presence of HBV, contact with body fluids contaminated with HBV may also result
in the transmission of HDV. Delta infection should be suspected in patients with
fulminant hepatitis and in chronic HBV carriers who have a sudden deterioration in
Considering HDV immunological assays, anti-HDV IgM indicates acute infection.
Anti-HDV indicates recent HDV infection or progression to chronic infection.