17 THE ADA PRACTICAL GUIDE TO EFFECTIVE INFECTION CONTROL Occupational Exposure to Bloodborne Pathogens The CDC defines occupational exposure in dentistry as a percutaneous injury (e.g., a needlestick or cut with a sharp object) or contact of mucous membrane or nonintact skin (e.g., exposed skin that is chapped, abraded, or with dermatitis) with blood, saliva, tissue, or other body fluids that are potentially infectious.1 Although vaccines play an important role in the infection control process, vaccination alone is not enough, because there are many bloodborne pathogens for which presently there are no vaccines, such as HIV and HCV. Occupational exposure to blood and saliva may occur in several ways: • Parenteral exposure (i.e., exposure occurring as a result of piercing the skin barrier, e.g., needlestick or cut with a sharp instrument) • Contact with mucous membranes (e.g., eye, nose or mouth) • Contact with non-intact skin (e.g., chapped skin, dermatitis or wounds) Epidemiological studies suggest that parenteral exposure poses a greater risk of infection than does exposure through mucous membranes or non-intact skin. Occupational transmission of HBV, HCV and HIV following parenteral exposure has been documented. Based on studies of health care personnel, the risk of acquiring an HBV infection following a single puncture with a needle contaminated with the virus ranges from 6% to 30%. Under similar circumstances, the risk of HCV or HIV infection is approximately 3% and 0.3%, respectively. The CDC defines occupational exposure in dentistry as a percutaneous injury (e.g., a needlestick or cut with a sharp object) or contact of mucous membrane or nonintact skin (e.g., exposed skin that is chapped, abraded, or with dermatitis) with blood, saliva, tissue, or other body fluids that are potentially infectious.1 Not all exposures result in infection. The risk of transmission of HBV, HCV and HIV, as well as other pathogens, is influenced by several factors, including: • Route of exposure (e.g., parenteral exposure or mucosal exposure) • The quantity of the virus transferred during an exposure incident • Susceptibility of the exposed dental team member For example, risk of infection increases when large numbers of viruses are transferred percutaneously to a susceptible team member.