Chlamydia becomes widest STD threat

NEW YORK — More than 1 million cases of chlamydia were reported in the United States last year, the most ever for a sexually transmitted disease, researchers from the Centers for Disease Control and Prevention (CDC) said.

Public-health experts partially blamed the increase on faltering public-health campaigns and a general failure among physicians to test patients for chlamydia and other bacterial infections that are transmitted sexually. About 19 million sexually transmitted diseases, commonly called STDs, of all kinds were recorded last year, half occurring among people between 15 and 24.

The spread of chlamydia is of intense concern, health officials said, because it is a silent infection with few obvious symptoms in its initial stages. It can lead to pelvic inflammatory disease and infertility. It's easily treated if caught early. Scores of cases, experts said, are likely going undiagnosed.

"We have reason to believe that chlamydia is dramatically underreported," said Dr. John Douglas, director of STD prevention at the CDC.

Though Douglas and his colleagues estimate 348 cases of chlamydia per 100,000 people in the population, he said government figures are probably off the mark and the number of new chlamydia cases last year was probably closer to 2.8 million.

"If [health-care]) providers think young women in their practice don't have chlamydia, they should think again," said Dr. Stuart Berman, a CDC epidemiologist.

Based on the new data, CDC researchers who examined the number of sexually transmitted diseases other than HIV last year estimated the cost in 2006 for treating STDs was $15 billion.

Gonorrhea rates also are rising after hitting a record low, and an increasing number of cases are caused by a "superbug" version resistant to common antibiotics.

Syphilis, a potentially deadly disease that first shows up as genital sores, is rising, too. About 9,800 cases of the most contagious forms of syphilis were reported in 2006, up from about 8,700 in 2005.

The rate of congenital syphilis — which can deform or kill babies — rose for the first time in 15 years.

"Hopefully we will not see this turn into a trend," said Dr. Khalil Ghanem, an infectious diseases specialist at Johns Hopkins University's School of medicine.

The CDC releases a report each year on chlamydia, gonorrhea and syphilis, three diseases caused by sexually transmitted bacteria.

Chlamydia is the most common. Nearly 1,031,000 cases were reported last year, up from 976,000 the year before. The count broke the single-year record for reported cases of a sexually transmitted disease, which was 1,013,436 cases of gonorrhea, set in 1978.

Since 1993, the CDC has recommended annual screening in sexually active women 15 to 25.

Chlamydia infection rates are more than seven times higher in black women than whites, and more than twice as high in black women as in Hispanics. But it's a risk women of all races should consider, CDC officials said.

The government tracks chlamydia, syphilis and gonorrhea to examine overall trends. Some widespread infections, among them those by the viruses that cause genital warts and genital herpes, aren't reported.

Material from USA Today and The Associated Press is included in this report.