Among all body fluids, blood contains the greatest proportion of HBV infectious particles and is the most critical vehicle of transmission. The other body fluids such as breast milk, semen, sweat and others are not efficient vehicles due to low quantities of infectious HBV.
One of the most efficient modes of transmission of HBV is percutaneous injury, but even these exposures account for only a minority of HBV infections. HBV has been demonstrated to survive in dried blood at room temperature on environmental surfaces for <1 week. The potential for HBV transmission through contact with environmental surfaces has been demonstrated in investigations of HBV outbreaks among patients and HCP in hemodialysis units. Vaccination can protect both DHCP and patients from HBV infection and, whenever possible, should be completed when dentists or other DHCP are in training and before they have contact with blood. Susceptible DHCP should submit themselves to HBV screening. If the DHCP is found to be negative to HBV antigen, it is highly recommended that they receive HBV vaccination. They should complete a series of 3-dose vaccination. After 2 months from completion of the 3rd dose, they should submit themselves to testing for antibody response. Those with inadequate antibody response should be revaccinated or evaluated to determine if they are HBV positive. Those revaccinated should again be tested for antibody response after 1 to 2 months. If there is still no antibody response to the second series, DHCP testing must be performed to determine if the DHCP is HBV positive. Nonresponders to vaccination who remain negative must be considered susceptible to HBV infection. Those who respond to the vaccination will remain immune even if they lose detectable antibodies over the years.