Description
Acute infection with hepatitis B virus (HBV) or
hepatitis C virus (HCV) can result in chronic hepatitis
if the infection persists for more than six months. The
rate of spontaneous clearance varies according to the
virus, the age at onset of infection and other factors.
Spontaneous clearance of HCV generally occurs
during the first six months of infection in
approximately a quarter of people with the infection,
with the remainder developing chronic hepatitis.
Although gradual histological progression occurs in
most people, the condition is often asymptomatic
for an extended period of time. Symptoms arise with
the development of complications of advanced liver
disease, but non-specific symptoms and impaired
quality of life are common among those with earlier
stages of liver disease. Cirrhosis occurs in an estimated
15–20% of people who develop chronic HCV infection,
15–40 years after the original infection. Among those
who develop cirrhosis, liver failure occurs in 20–30%
and hepatocellular carcinoma (HCC) develops in
10–15% over 10 years.1 Estimates of disease
progression in hepatitis C are outlined in Figure 7.1.
The natural history of HBV infection is primarily
determined by the age of the person at the onset
of infection. When acquired at birth or during early
childhood, the risk of developing chronic infection is
high, with only 2% of infants spontaneously clearing
the virus within three years of infection and 15%
clearing the virus within 20 years. Among people with
perinatally-acquired HBV, 40–50% of males and 15%
of females die from the liver-related causes.2
In the case of adult-acquired HBV infection, however,
the situation is reversed, with spontaneous clearance
being the rule. Acute liver failure occurs rarely, and
only 3–5% of adults with acute infection go on to
develop chronic HBV infection. In many cases, chronic
HBV infection does not result in symptoms or longterm
problems, although 20–30% of people will
progress to cirrhosis.
These differences in outcome between perinatal
and adult-acquired infection are outlined in Figure
7.2. Of those with compensated cirrhosis, 20–30%
will develop liver failure (decompensated cirrhosis)
and 10–20% will develop HCC over the next ten
years. Survival rates are high among those with
compensated cirrhosis but much lower among those
with liver failure (85% versus 25% at five years).
Symptoms and signs of chronic viral
hepatitis
Chronic viral hepatitis is frequently hidden due to
the asymptomatic nature of liver disease in a large
proportion of people and the slowness or absence of
progression to advanced liver disease. The absence
of symptoms and abnormal clinical signs, therefore,
does not exclude significant liver disease. However,
early diagnosis and treatment may improve prognosis
and, where appropriate, patients should be offered
treatment options.
Although there is a great deal of overlap, symptoms
and signs of chronic viral hepatitis can be divided into
those associated with:
• Early or slowly progressive liver disease
• Progressive liver disease
• Advanced liver disease complications
• Extrahepatic manifestations
In this classification, ‘early or slowly progressive liver
disease’ includes people with chronic hepatitis C who
progress slowly and may have early fibrosis.