Sexually transmitted disease rates continue to increase.

Rates of chlamydia, gonorrhea, and syphilis increased in the United States during the past year and continued recent upward trends, according to a report from the Centers for Disease Control and Prevention.

"Young women, racial and ethnic populations, and men who have sex with men are particularly hard hit by these diseases," Dr. John M. Douglas Jr., director of the CDC's Division of Sexually Transmitted Disease Prevention, said in a teleconference sponsored by the CDC.

All three diseases are treatable, especially if diagnosed early. If left untreated, the severe health consequences include pelvic inflammatory disease, infertility, increased risk for HIV infection, organ damage, and death. The direct medical costs associated with STDs in the United States were estimated at nearly $15 billion in 2006, the researchers stated in the report, "Sexually Transmitted Disease Surveillance 2006," which was presented in the telebriefing.

Of the three diseases, the increased chlamydia rates represent the greatest public health impact, Dr. Douglas said.

The national rate of reported cases of chlamydia increased by 5.6% from 2005 to 2006, from 329.4 cases per 100,000 persons in 2005 to 347.8 cases in 2006.

Chlamydia hits hardest among adolescent girls and young women--the highest chlamydia rate was reported in young women aged 15-19 years (2,863 cases per 100,000 persons), followed by women aged 20-24 years (2,797 cases). And racial disparity is high: The chlamydia rate among black women was more than seven times higher that of white women and more than twice as high as that of Hispanic women.

Given the high rate of chlamydia in young women, the CDC recommends screening sexually active women younger than 26 years. Chlamydia screening is also advised for older women with new or multiple sex partners. Based on recent evidence that chlamydia reinfection can occur in women whose partners remain untreated, the CDC's treatment guidelines include retesting patients 3 months after treatment.

Gonorrhea rates increased for the second consecutive year, following a plateau in reported disease rates from 1997 to 2005. "The racial disparities are stark" in reported gonorrhea cases, Dr. Douglas said. Overall, the rate among blacks is 18 times higher than in whites, he said.

Gonorrhea rates also continue to vary by region. As in previous years, the southern region of the United States had the highest overall gonorrhea rate in 2006, at 159 cases per 100,000 persons. But rates in the South rose by 12.3% in 2006, representing the first notable increase in 8 years.

"We are also concerned about increases in the West," Dr. Douglas said. Gonorrhea cases in the West increased by 2.9% between 2005 and 2006, contributing to a 32% increase between 2002 and 2006.

Untreated gonorrhea can, among other complications, increase a person's risk for HIV if he or she is exposed. But gonorrhea treatment has become more challenging because evidence of fluoroquinolone resistance--especially among men who have sex with men--prompted the CDC in April 2007 to stop recommending fluoroquinolones as treatment for gonorrhea. As an alternative, the CDC recommends cephalosporins to treat gonorrhea.

Rates of primary and secondary syphilis in the United States increased by nearly 14% from 2005 to 2006, but the most notable increase occurred among men who have sex with men. Syphilis rates among that group increased by 54% from 2002 to 2006, Dr. Douglas said.

Although syphilis has the least impact on the population as a whole, the rise in reported cases for the sixth consecutive year is cause for concern, Dr. Douglas said, given a steady decrease during the 1990s.

The report's data provide an incomplete picture of sexually transmitted diseases in the United States, the researchers cautioned, because many cases of chlamydia, gonorrhea, and syphilis are not reported. In addition, some types of STDs, including genital herpes and human papillomavirus, are not tracked by the CDC but contribute to the overall disease burden of STDs, he noted.

The full report is at www.cdc.gov/std/stats.

BY HEIDI SPLETE

Senior Writer