December 01, 2009
2 min read

CDC: Chlamydia and gonorrhea remain most common STDs in United States

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Adolescent girls and women aged 15 to 24 years accounted for approximately half of the chlamydia cases and one–third of the gonorrhea cases in the United States in 2008, according to a new sexually transmitted diseases surveillance data published recently by the CDC.

Almost half of the 19 million STD infections in the United States occurred among individuals aged 15 to 24 years. There were 1.5 million cases of chlamydia and gonorrhea reported, making them the first and second most common infectious diseases in the country. Girls aged between 15 and 19 years and women aged between 20 and 24 years bore the largest burden of chlamydia and gonorrhea infections. Racial disparities continue to exist for the three reportable STDs accounted for in the CDC report.

Number of cases

According to the report, there were 1.2 million cases of chlamydia nationwide in 2008. The rate increased 9.2% to 401.3 cases per 100,000 population. The researchers estimate that increases in reporting and screening and more sensitive tests may have accounted for the increase, but that there may be as many as 2.8 million cases nationwide per year.

Gonorrhea rates decreased from 118 to 111.6 cases per 100,000 population between 2007 and 2008, but the number of reported cases increased from 336,742 to 355,991.

There was an 18% increase in syphilis cases between 2007 and 2008.

Populations most affected

Rates of STDs among young women and minority populations continue to be of concern to CDC experts. Among girls aged 15 to 19 years, there were 342,875 reported cases of chlamydia; the rate of gonorrhea was 636.8 cases per 100,000 females. Among women aged 20 to 24 years, the rate of chlamydia was 3,179.9 cases per 100,000 females; the rate of gonorrhea was 608.6 cases per 100,000 females.

Rates of chlamydia increased 45% among men between 2004 and 2008.

Most syphilis cases were among men who have sex with men. The rate of syphilis among women increased 36% between 2007 and 2008, from 1.1 cases to 1.5 cases per 100,000 females. Rates of congenital syphilis remained stable.

Blacks accounted for 70% of gonorrhea cases in 2008. This is the most severe racial disparity of all reportable STDs and one of the most severe disparities of any infection. Blacks were 20 times more likely to acquire gonorrhea than whites. The rate of gonorrhea among black girls aged 15 to 19 years was 2,934.6 cases per 100,000 females. Among black women aged 20 to 24 years, the rate was 2,777 cases per 100,000.

Blacks were eight times more likely than whites to acquire chlamydia or syphilis in 2008. Black women aged 15 to 24 years were disproportionately affected by chlamydia, while black men and black women saw increases in syphilis rates.

Hispanics were more than twice as likely as whites to acquire syphilis or gonorrhea and three times as likely as whites to acquire chlamydia.

American Indian and Alaska Native populations had rates of gonorrhea that were 3.6 times that of whites and rates of chlamydia that were 4.7 times that of whites.

The researchers wrote that racial disparities may be due to the fact that racial minorities are more likely than whites to seek care in public health clinics that report STDs. However, structural barriers to prevention and treatment exist among racial minorities.

The researchers also wrote that increased screening among all young women, MSM and pregnant women may be ways to combat the toll of STDs. They suggested that behavioral interventions as the individual and small group level also may be effective and that sex partners of patients with one of these infections should be screened.

Pediatrics. 2009; 124:1505-1512.