Hepatitis
causes inflammation of the liver and is most often caused by a virus,
of which there are 6 types: hepatitis A (HAV), hepatitis B (HBV),
hepatitis C (HCV), hepatitis D (HDV), hepatitis E (HEV), hepatitis G
(HGV). All of these viruses affect the liver and have similar
symptoms, however they are spread in different ways, have different
treatments and have different long term affects. HAV, HBV and HCV are
the most common types of hepatitis virus, with HBV and HCV infection
being the biggest risk factors for liver cancer. In fact, hepatitis B
and hepatitis C cause approximately 71% of liver cancer cases
worldwide, with people infected with both HBV and HCV most at risk.
Hepatitis
B
Hepatitis
B is the most common liver infection in the world. HBV is spread
through contact with infected blood, semen or other bodily fluids.
During the first 6 months after infection it is considered to be
'acute' hepatitis. If hepatitis B virus (HBV) tests continue to be
positive for more than 6 months after infection the affected person
is considered to have 'chronic' hepatitis B. Up to 1 in 4 people with
chronic hepatitis B will die from either liver cancer or liver
failure due to cirrhosis unless they receive appropriate care and
treatment. Chronic hepatitis B causes prolonged liver damage which
may result in cirrhosis (liver scarring) and lead to liver cancer.
Worldwide,
an estimated 257 million people have been infected with HBV, with
approximately 887,000 deaths resulting from this viral infection in
2015. Almost 240,000 people have chronic hepatitis B in Australia,
however there is thought to also be a large number of people in
Australia living with hepatitis B that have not yet been diagnosed.
There
has been a hepatitis
B vaccine
available since 1982, with the vaccination programme commencing in
Australia in 1988. The vaccine provides over 90% protection against
hepatitis B and is your best defence against this disease.
Hepatitis
C
Hepatitis
C is the other major type of viral hepatitis responsible for
increasing your risk of liver cancer. Over 90% of cases in Australia
are caused by HCV 1a and 1b (54% prevalence) and HCV 3a (37%
prevalence) genotypes. The biggest risk of contracting HCV is from
injecting drugs, particularly if you share needles or use dirty
needles which may have come into contact with infected blood. Other
potential sources of infection include unhygienic needles being used
for tattooing or piercings, with an additional (yet smaller) risk of
contracting HCV through unprotected sexual intercourse with an
infected person. Hepatitis C can cause mild to serious illness, also
with the potential to become chronic, cause cirrhosis and lead to
liver cancer.
Globally,
approximately 71 million people have chronic hepatitis C infection,
with approximately 399,000 people dying each year. An estimated
230,000 people in Australia are currently living with hepatitis C
infection.
There
is currently no vaccine for HCV, however a number of preventative
strategies are advised to tackle the issue of HCV infection. HCV can
be treated relatively easily, with the current recommended treatment
being direct
acting antivirals (DAAs). DAAs have changed
the therapeutic landscape for hepatitis C with an estimated 90%
curative rate. However, HCV infection continues to have significant
morbidity and mortality with traditionally
less than 2% of affected Australians receiving treatment.
According
to the an AIHW report on Cancer
in Australia 2017,
liver cancer has had the second highest percentage change in
incidence rate of all cancers over the last 35 years with an increase
of over 300%. Reducing viral hepatitis is a key step in
reducing primary liver cancer.
Useful
resources
Hepatitis
Australia
WHO
Hepatitis B fact sheet
WHO
Hepatitis C fact sheet
Cancer
council Victoria
Better
Health Victoria
Cancer
in Australia 2017
