Hepatitis B is a blood-borne virus, and thus, the only way to get the disease is to be exposed to the blood of someone who is a carrier. The most common way that children become infected is during childbirth. If the mother is a hepatitis B carrier, she can transfer the virus to the baby at birth. Fortunately, in most countries, pregnant women are routinely tested for this virus during their pregnancy. If a woman is found to be a carrier, the baby receives both a vaccine and a special immune globulin that contains antibodies against hepatitis B. This decreases the baby’s risk of acquiring the infection.
Other methods of spreading this disease include sexual intercourse and IV drug use. A blood transfusion is another method of transmission, but because the blood supply is screened, the risk there is very low. Finally, direct exposure to the blood of a carrier can transmit this infection. Thus, if your child is exposed to a bleeding cut of another child who is a carrier and that blood touches your child’s blood (through an open wound or via mucus membranes like the mouth), then your child could become infected.
Overall, your baby’s risk of being exposed to this virus is low. Almost all mothers are screened during pregnancy, and most infants do not have as many risk factors as adults.