New Data Show Heavy Impact of Chlamydia on U.S. Men and Women

AMSTERDAM, the Netherlands -- New data show a heavy burden of chlamydia in young women and men in the United States, particularly among pregnant women attending publicly funded clinics and economically disadvantaged youth, according to the Centers for Disease Control and Prevention (CDC). Other research found that 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. These new data were presented at the 16th biennial meeting of the International Society for Sexually Transmitted Diseases Research (ISSTDR), July 10-13, in Amsterdam.

STDs often have no symptoms and therefore frequently go unrecognized and undiagnosed, said Dr. John Douglas, director of CDCs STD prevention programs. 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.

In the first nationally representative study of chlamydia prevalence in the general adult population (ages 14-39), CDC researchers found a chlamydia prevalence of 2.2 percent and no significant differences between women and men overall. Nearly 1 in 20 women between the ages of 14-19 (4.6 percent) were infected the highest proportion of any age group. Among men, 20- to 29-year-olds were most heavily affected, with a prevalence of 3.2 percent. Prevalence was higher among blacks in all age groups, at 6.4 percent, compared to 1.5 percent among whites. The findings were based on responses from participants in the National Health and Nutrition Examination Survey (NHANES) from 1999 to 2002.

Two separate analyses of economically disadvantaged young adults (16-24) enrolled in a national job training program found that roughly 1 in 10 were infected with chlamydia. Analysis 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 percent were infected. Prevalence was highest among 16-year-old women at 13.3 percent.

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

In a separate study, researchers analyzed data on more than 86,000 women ages 15-45 who were screened for chlamydia at publicly funded prenatal clinics in 18 states 1. Test results were positive for 5.8 percent, with the highest prevalence among 15- to 19-year-olds (9.7 percent). Prevalence among black women (11.1 percent) was nearly four times that of white (3.9 percent) and Hispanic (3.8 percent) women. Because chlamydia can have serious consequences for newborns, including pneumonia and conjunctivitis, study authors recommend continued emphasis on prenatal chlamydia screening.

In 2003, 877,478 cases of chlamydia were reported in the United States, making it the nations most commonly reported STD. Chlamydia is easily cured with antibiotics but is often undiagnosed because of its lack of symptoms. Besides infertility, the disease can cause other serious health problems in women: pelvic inflammatory disease, ectopic pregnancy, and chronic pelvic pain. CDC recommends the delay of sexual initiation among teens as the only 100 percent effective method of STD prevention, and annual chlamydia screening for all sexually active women under age 25.

Two other CDC studies presented at the 16th ISSTDR meeting found that federal STD prevention efforts are having a dramatic impact in reducing disease and associated health costs.

The first study examined the impact of federal STD prevention efforts over the past 33 years, estimating that approximately 32 million cases of gonorrhea were averted from 1971 to 2003 as a result of such efforts. Researchers estimates were based on historical records of federal funding to state and local health departments for STD prevention and previously published research about the impact of the funding on gonorrhea rates at the state level. The study demonstrated 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. This estimate was based on reported cases of the two diseases in the United States, coupled with published estimates of direct medical costs per STD case. Authors calculated that the total direct medical cost of gonorrhea and syphilis was $3.8 billion over the 14-year period, compared to $8.9 billion if STD rates had remained at their 1990 levels. Because gonorrhea and syphilis infection are known to increase the risk of HIV transmission, a significant portion of the total savings ($3.9 billion) reflected HIV infections that were averted due to reduced gonorrhea and syphilis rates.

STD prevention efforts are increasingly shown to be effective and economically sound strategies for improving the nations health, said Douglas. Current challenges demand that we remain vigilant and continue working to make sure that effective prevention programs are available in every community and to all who need them.

Source: CDC