...Hepatitis B is the most common chronic infectious disease in the world. Over 300 million people worldwide are infected with the virus. While most chronic carriers live in Asia and Africa, 1.2 million are thought to reside in the United States. Fortunately, as a result of vaccination, the incidence of acute hepatitis B, during the time period of 1990-2002, fell 67% from 8.5 per 100,000 population (21,102 total cases reported) to 2.8 per 100,000 (8,604 total cases reported). The most significant decline in acute hepatitis B occurred among persons aged 0-19 years, from 3.0 to 0.3 in 2002. However, not all groups are in continuous decline. Since 1999, after more than a decade in decline, the incidence of acute hepatitis B has increased among males 19 years of age. The most common risk factors reported among adults with new infection continue to be multiple sex partners, men who have sex with men, and injection drug abuse...