The mortality rate of African-Americans infected with HIV has dropped sharply in recent years and the gap between whites and blacks is narrowing, new figures show.

A new report by the US Centers for Disease Control and Prevention found that the death rate for blacks infected by the HIV virus dropped 28 percent from 2008 to 2012, a greater decrease than other races and ethnicities.

The CDC gave no explanation for the drop, but various groups have launched vigorous information campaigns in recent years targeting high-risk groups.

In 2012, the latest year for which data was available, blacks still had the highest death rate overall, with 20.5 percent, compared with 18.1 percent for whites and 13.9 percent for Hispanics or Latinos.

Blacks are infected with HIV at higher rates than other groups.

The CDC noted that African Americans living with HIV were less likely to get diagnosed, with 15 percent unaware of their infection in 2011, compared with 12 percent of whites.

"Focusing prevention and care efforts on minority populations with a disproportionate HIV burden could lead to further reduction, if not elimination, of health disparities, such as higher mortality and help achieve the goals of the National HIV/AIDS Strategy," the report said.