HBV Risk Groups
The children of HBV -infected mothers are not the only risk group, and in the United States they are not even the largest risk group. Among adolescents and adults, who constitute a much larger part of the infected population, HBV is transmitted in various ways: sexual contact, especially among homosexual men and people with many heterosexual partners; injection drug use; occupational exposure (among health care workers, for example); household contact with someone who has an acute infection or is a chronic carrier of the virus (this can be by some inadvertent contact with blood, such as that left on a razor or toothbrush); and blood or blood product transfusion. And there is still considerable mystery about HBV infection: despite what is known about these routes of transmission, almost one-third of people with HBV do not have any identifiable risk factor at all. Rates of infection differ among various racial groups: prevalence of the infection among blacks is three to four times greater than among whites.
There are no documented cases of hepatitis b information being transmitted by a person being breathed on by someone with the illness, catching it from an insect bite, or getting it through contaminated water.
Vaccination programs for these risk groups have not been very effective in reducing transmission. Three doses of the vaccine are required and it has been difficult to persuade injection drug users, for example, to follow through on all three shots. Sometimes health care providers are not aware of which groups are at high risk, and so do not identify people who should be vaccinated. Screening of blood donations has revealed carriers, but efforts to vaccinate their household members and sexual contacts have met with limited success. Health care workers have had somewhat better luck: Vaccination among this group has reduced rates of infection. But none of this has had much effect on the general rates of HBV infection.
By 1997, about 84 percent of children between nineteen and thirty-five months of age had been vaccinated. Although no figures are available for kids aged eleven and twelve years, many states have implemented middleschool entry requirements for hepatitis B vaccination, so coverage will increase among these preteens.
