According to the Centers for Disease Control and Prevention, about 1.1 million people were living with HIV in the United States at the end of 2015. That number has likely grown in recent years as injection drug use has increased. In 2016, according to the Philadelphia Department of Public Health, the city had the highest rate of new infections compared with other large cities. Both in Philadelphia and nationally, black men who have sex with men or inject drugs are at the highest risk.