According to new estimates from the Centers for Disease Control and Prevention that are based on mathematical modeling, the national annual HIV infection rate dropped by 15 percent between 2008 and 2015, from 45,200 to 38,500 new transmissions. The annual infection rate declined by 6.3 percent among heterosexuals and 11 percent among people who inject drugs (PWID). However, the 15-year decline seen among PWID appears to be leveling off, possibly because of the expanding opioid epidemic. The annual infection rate held steady among men who have sex with men (MSM) overall, at about 26,200 to 26,700 annual infections. Among MSM, the annual rate rose by 45 percent among 25- to 34-year-olds, rose by 25 percent among Latinos, held steady among African Americans and declined 19 percent among whites. MSM had an annual infection rate 16 times that of PWID and 135 times that of heterosexuals.