New CDC data show high rates of chlamydia in young people in the U.S.

September 2005

America’s youth are bearing a heavy burden from chlamydia, according to a CDC study presented here at the 16th biennial meeting of the International Society for Sexually Transmitted Diseases Research in Amsterdam, Netherlands.

However, federal sexually transmitted disease (STD) prevention efforts have prevented millions of infections and saved an estimated $5 billion in direct medical costs over the past 30 years, the CDC said.

“Stepping up screening and prevention efforts is critical to ensuring that young people do not suffer the long-term effects of untreated chlamydia, including infertility,” said John Douglas, MD, director of the CDC’s STD prevention programs, in a press release.

Toll greatest in young women

CDC researchers found 2.2% chlamydia prevalence in a nationally representative study of prevalence in people from 14 to 39 years old. There were no significant differences between women and men overall. Nearly one in 20 teenage girls between 14 and 19 (4.6%) had chlamydia — the highest proportion of any age group. The most heavily affected age among men were those between 20 and 29, with 3.2% prevalence. Prevalence was higher among blacks in all age groups, at 6.4%, compared with 1.5% among whites. Researchers based the findings on responses from participants in the National Health and Nutrition Examination Survey from 1999 to 2002, according to the CDC release.

Two separate analyses of economically disadvantaged young adults (16-24) enrolled in a national job-training program found that about one in 10 had chlamydia. Analyses of test results from more than 106,000 young women from 1998 through 2004, nearly two-thirds of whom were black or Hispanic, found that 10.9% had the infection. Prevalence was highest among 16-year-old females (13.3%).

The CDC’s evaluation of test results from more than 50,000 young men (63% black or Hispanic) in the same job program from July 2003 to December 2004 represented the first widespread chlamydia screening among U.S. men. The results showed 8.2% had chlamydia, with the highest rate among 20- to 24-year-olds (8.8%). Only 2.4% of men with chlamydia reported symptoms, suggesting they would have remained undiagnosed without the screening.

In a separate study, researchers analyzed data on more than 86,000 women between ages 15 and 45 whom researchers screened for chlamydia at publicly funded prenatal clinics in 18 states: Arkansas, Delaware, Florida, Illinois, Kansas, Kentucky, Louisiana, Maryland, Mississippi, Nebraska, New Jersey, New Mexico, North Carolina, Oklahoma, Oregon, South Carolina, Tennessee and Virginia. Test results were positive for 5.8% of the participants, with the highest prevalence among 15- to 19-year-olds (9.7%). Prevalence among black women (11.1%) was nearly four times that of white (3.9%) and Hispanic (3.8%) women. Because of the consequences for newborns, researchers recommended continued emphasis on prenatal chlamydia screening.

In 2003, 877,478 cases of chlamydia were reported in the United States, making it the nation’s most common STD. Physicians can easily cure chlamydia with antibiotics; however, the infection is often asymptomatic. The infection can cause infertility, pelvic inflammatory disease, ectopic pregnancy and chronic pelvic pain in women. The CDC recommends delaying sex among teenagers as the only 100% effective method of STD prevention and annual chlamydia screening for all sexually active women younger than 25.

STD prevention efforts

Two other CDC studies presented at the meeting found that federal STD prevention efforts are reducing infection and associated health costs.

The first examined the effect of federal STD prevention efforts over the past 33 years, estimating that about 32 million cases of gonorrhea were averted from 1971 to 2003 as a result of the efforts. Researchers based their estimates on historical records of federal funding to state and local health departments for STD prevention and previously published research about the effect of the funding on state gonorrhea rates. The study showed that STD prevention programs paid for themselves. Savings realized by preventing gonorrhea exceeded the STD prevention program expenditures by $1.4 billion during the 33-year period.

In the second analysis, researchers estimated that reductions in annual incidence of gonorrhea and syphilis from 1990 to 2003 saved $5 billion in direct medical costs. Researchers based this estimate on reported U.S. cases of the two infections and published estimates of direct medical costs per STD case. Researchers calculated the total direct medical cost of gonorrhea and syphilis over the 14-year period: $3.8 billion compared with $8.9 billion if STD rates had remained at their levels in 1990. Because infection with gonorrhea and syphilis increases the risk of HIV transmission, a significant portion of the savings ($3.9 billion) reflected HIV infections that were averted due to reduced gonorrhea and syphilis rates.

For more information:

• Chesson H. Estimated gonorrhea rates in the United States in the absence of federally funded prevention efforts, 1971-2003. Poster MP-194.
• Chesson H, Gift T, Pulver A. The value of reductions in gonorrhea and syphilis incidence in the United States, 1990-2003. Poster MP-193.
• Datta SD, Sternberg M, Johnson R, et. al. Prevalence of chlamydia and gonorrhea in the United States among persons aged 14-39 years, 1999-2002. Abstract TP-078.
• Joesoef M, Mosure DJ, Dicker LW. Chlamydia trachomatis and Neisseria gonorrhoeae infections in women aged 15-24 years attending prenatal care clinics in the U.S., 2003. Abstract TP-066.
• Joesoef M, Mosure DJ. Trends in Chlamydia trachomatis infections in young women entering a national job training program, 1998-2004. Abstract TB-065.
• Mosure DJ, Joesoef MR. A new widespread screening program in the U.S. for Chlamydia in males: prevalence in young men entering a job training program. Abstract TP-067.

• All were presented at the 16th biennial meeting of the International Society for Sexually Transmitted Diseases Research. July 10-13. Amsterdam, Netherlands.