Major gaps exist in the timely identification and immunization of infants born to women infected with hepatitis B virus (HBV). Timely identification of such newborns is critical because immunoprophylaxis at birth can prevent HBV transmission in over 90% of newborns. In contrast, more than 90% of newborns infected with HBV will develop chronic hepatitis B, which confers a 200-fold increased risk of liver cancer. To address this critical public health issue, the Advisory Committee on Immunization Practices (ACIP) issued recommendations in 2005 to improve nationwide prevention of perinatal HBV transmission. The next step in the widespread adoption of these guidelines is to translate them into a public health strategy that fosters rapid uptake of the recommended actions. Therefore, this research project aims both to understand the factors that impede or facilitate the adoption of perinatal hepatitis B prevention guidelines, and to translate the ACIP recommendations into concrete implementation of prevention services for pregnant women infected with HBV, their newborn infants, and other household and sexual contacts. Our specific aims are as follows: 1) to increase by at least 300% the number of obstetricians that provide timely antenatal reporting of pregnant women infected with HBV;2) to increase by at least 10% the enrollment of exposed newborns in case management services;3) to improve to over 80% the rate of post-vaccination serologic testing among exposed newborns;4) to increase to over 75% the proportion of delivery hospitals that adopt standardized procedures for management of HBV-positive pregnant women, their newborns, and their household and sexual contacts;and 5) to improve knowledge about hepatitis B among HBV-positive pregnant women. Our project will be based in two California counties where at least one-quarter of the population is composed of Asian and Pacific Islander Americans-the racial/ethnic group at highest risk of perinatal HBV transmission. Our strategy focuses on education of health care providers, pregnant women, and their household contacts through the dissemination of culturally tailored educational materials;provision of standardized "provider packet for HBsAg positive pregnant women" to facilitate the adoption of case reporting and management guidelines by hospital personnel;and informational support for pregnant women infected with HBV. We will assess pre- and post-intervention practices, knowledge, and barriers and facilitators to care among stakeholders, and will evaluate the cost effectiveness of our intervention to address its future sustainability. The ultimate goal of our study is to develop a comprehensive program for perinatal hepatitis B prevention that can be disseminated widely and integrated seamlessly into existing public health service programs to result in a more effective, efficient, and sustainable strategy for long-term reduction of disease and death due to hepatitis B.