Cook County, Ill., Ranks High in Sexually Transmitted Disease: STD Treatment Costs U.S. Health Care System $16.4 Billion a Year

New CDC figures show the United States logs 19 million new STD cases each year. Less than half the people who should be screened receive the recommended STD tests, CDC said. If left undiagnosed and untreated, STDs raise the risk of HIV infection.

The report found large racial disparities in STD rates, reflecting a range of factors including poverty, lack of access to health care, and high STD rates in predominantly black communities that increase one's risk of infection. Blacks have a gonorrhea rate 20 times that of whites and almost 10 times that of Hispanics. Blacks accounted for 48 percent of chlamydia cases in 2009, reaching a rate eight times that of whites and three times that of Hispanics.

Since 2000, syphilis rates have been climbing among men who have sex with men; last year MSM accounted for 62 percent of all syphilis cases, up from just 4 percent in 2000. The rate of syphilis among blacks was nine times higher than among whites and four times higher than among Hispanics.

According to the report, gonorrhea reached a record low last year, with declines in all racial and ethnic groups. However, Cook County ranked highest with 13,330 gonorrhea reports in 2009, a jump of 7 percent in the metropolitan Chicago area since 2005.

CDC estimates there are 2.8 million cases of chlamydia annually - more than double the number actually reported. With 35,531 chlamydia reports, Cook County ranked second behind Los Angeles County's 46,977 cases.

For syphilis, Cook County also ranked second behind Los Angeles, with 634 cases logged in 2009. Since 2005, the number of reported syphilis diagnoses in the Chicago area has increased by 44 percent.

The report, "Notifiable Diseases and Mortality Tables," was published in CDC's Morbidity and Mortality Weekly Report (2010;59(46):1525-1538).