Hepatitis is an inflammation of the liver. (Hepat- means
The condition can be self-limiting or can progress to
fibrosis (scarring), cirrhosis or liver cancer. Hepatitis
viruses are the most common cause of hepatitis in the world
but other infections, toxic substances (e.g. alcohol,
certain drugs), and autoimmune diseases can also cause
There are 5 main hepatitis viruses, referred to as types A,
B, C, D and E. These 5 types are of greatest concern because
of the burden of illness and death they cause and the
potential for outbreaks and epidemic spread. In particular,
types B and C lead to chronic disease in hundreds of
millions of people and, together, are the most common cause
of liver cirrhosis and cancer.
Hepatitis A virus (HAV) is
present in the faeces of infected persons and is most often
transmitted through consumption of contaminated water or
food. Safe and
effective vaccines are available to prevent HAV.
Hepatitis B virus (HBV) is
transmitted through exposure to infective blood, semen, and
other body fluids. HBV can be transmitted from infected
mothers to infants at the time of birth or from family
member to infant in early childhood. Transmission may also
occur through transfusions of HBV-contaminated blood and
blood products, contaminated injections during medical
procedures, and through injection drug use. HBV also poses a
risk to healthcare workers who sustain accidental needle
stick injuries while caring for infected-HBV patients.
Safe and effective
vaccines are available to prevent HBV.
Hepatitis C virus (HCV) is
mostly transmitted through exposure to infective blood. This
may happen through transfusions of HCV-contaminated blood
and blood products, contaminated injections during medical
procedures, and through injection drug use. Sexual
transmission is also possible, but is much less common.
There is no vaccine for HCV. There is however a cure for HCV
Hepatitis D virus (HDV) infections
occur only in those who are infected with HBV. The dual
infection of HDV and HBV can result in a more serious
disease and worse outcome. Hepatitis B vaccines provide
protection from HDV infection.
Hepatitis E virus (HEV) is
mostly transmitted through consumption of contaminated water
or food. HEV is a common cause of hepatitis outbreaks in
developing parts of the world and is increasingly recognized
as an important cause of disease in developed countries.
Safe and effective vaccines to prevent HEV infection have
been developed but are not widely available.
Screening and testing is the only way to know if someone has