Rates of the sexually transmitted infections chlamydia, gonorrhea and syphilis are rising in the United Sates, with more than a million cases reported in 2007. A report released by the U.S. Centers for Disease Control and Prevention (CDC) has found that all three STDs disproportionately affect African Americans, especially black women.

According to the report, syphilis was seven times more common among blacks than whites, chlamydia was eight times more common and gonorrhea was 19 times more common. The report also found that black women ages 15 to 19 had the highest rates of both chlamydia and gonorrhea with 9,647 and 2,956 per 100,000 population.

The CDC estimates that the increased cases of STIs cost the American healthcare system an estimated $15.3 billion annually. “These diseases can be treated, and we need to have better awareness about how extensive these infections are and what the prevention opportunities are,” said John M. Douglas Jr., MD, director of the CDC’s Division of STD Prevention.