BOSTON - Gay and bisexual men in Massachusetts continue to be the hardest hit by the AIDS epidemic with a significant percentage of new cases appearing among minority men. That’s according to a new report by the Massachusetts Department of Public Health that found while the state has had success battling the disease among injection drug users and heterosexual men and women, it has had less success among gay and bisexual men. More than half of HIV infections between 2004 and 2006 were among gay and bisexual men even though they make up less than 10 percent of the population.