The older boy was infected by his mother at the time of birth.
All but 4 of the 188 victims were infected in the hospital or by a family member at home.
An estimated 170,000 adults and children were infected at the end of 2004.
While the tests can show that individuals have been infected at some time in their lives, they cannot determine when.
About a third of the world population has been infected at one point in their lives, including 350 million who are chronic carriers.
You may be infected with more than one genotype at a time.
Almost everyone is infected at one point or another.
Sometimes a baby is infected at birth because the mother has hepatitis.
It is unclear how many people worldwide are infected at present.
More than half the adults in the United States have been infected at some time.