Clinical Course and Symptoms
Infection
with HDV is double trouble since it always infects someone who already has HBV infection
as well. HDV causes similar symptoms as HBV does but the severity can be much
worse (see table below). In fact the mortality rate of HDV
can be up to ten times higher the rate of HBV-infection alone. There are two
types of HDV infection which have different courses.
HDV-HBV coinfection is
where someone gets HDV and HBV at the same time. This is the less serious form and
only results in chronic liver disease in 1-3% of cases. However, the HDV
presence does make the risk greater than if there was just HBV alone.
HDV-HBV superinfection is the more common and more serious form of HDV. This is where someone who already has chronic Hepatitis B suddenly gets a worse infection because of exposure to HDV. This is also called fulminant hepatitis. It turns out that most cases where viral hepatitis suddenly becomes very sever are due to HDV. This condition can lead to chronic Hepatitis D disease which is often fatal.
Superinfection |
Large numbers of hepatocytes are already producing
HBsAg |
|
1 ACUTE HEPATITIS |
2 FULMINANT HEPATITIS |
3 CHRONIC TYPE D HEPATITIS |
Symptoms: Incubation period of 3 to 7 weeks HBV-HDV coinfection could lead to more severe cases than HBV-only infection Higher incidence of fulminant hepatitis Low incidence of chronic hepatitis (1-3%)
|
Symptoms severe, rare form of viral hepatitis Mortality: 80% ten times more likely than HBV-only cases
|
Almost all superinfection cases proceed to chronic hepatitis Symptoms 70-80% develop cirrhosis compared to 15-30% with only chronic HBV infection Cirrhosis leads to liver failure and portal hypertension Death results from bleeding, hepatic coma, infection, or kidney failure |