Risky sex breeds neglected epidemic.

The United States has a secret, and the Institute of Medicine (IOM) wants to rouse the nation to do something about it. In a report called "The Hidden Epidemic," IOM says that the United States has failed to respond adequately to sexually transmitted diseases (STDs), even though it has the highest rates of infection in the developed world.

Twelve million people in the United States, one-fourth of them adolescents, get STDs each year, according to the report. Several studies show that U.S. rates of infection are 50 to 100 times those of other developed nations, IOM states. For example, 150 of every 100,000 people in the United States have gonorrhea, compared to 3 per 100,000 in Sweden and 18.6 per 100,000 in Canada.

Thousands of people die annually of complications because the United States lacks an "effective national system" for curbing the epidemic, IOM contends.

Only a concerted effort to screen people for STDs, treat them, and educate others about the risks of infection will stem the tide of disease, Helene Gayle of the federal Centers for Disease Control and Prevention in Atlanta said last week at the American Public Health Association's annual meeting in New York.

The IOM study found that all levels of government spent just $1 to prevent STDs for every $43 spent on drugs, tests, doctors' fees, and hospitalization. In all, these diseases cost the nation $17 billion a year.

Thirty-two percent of men and women in a 1995 government study could not name any STD other than AIDS. There are more than a dozen such diseases, including gonorrhea, syphilis, herpes, and viral hepatitis. Bacterial STDs can be cured with antibiotics, although some antibiotic-resistant strains are spreading. Without treatment, STDs can cause sterility, pelvic inflammatory disease, and cancer.

Several new sexually transmitted microbes have emerged in the last 2 decades. Two of them, HIV I and II, cause AIDS. Others are human papillomavirus (HPV), a cause of cervical cancer; HTLV-I, which can cause a rare cancer or a paralytic illness; mycoplasma, which causes urethritis; mobiluncus, which causes vaginosis; and human herpes virus 8, which causes Kaposi's sarcoma and lymphoma.

Although relatively new, HPV afflicts 24 million women in the United States. Studies have linked the virus to 80 percent of all cases of invasive cervical cancer, a malignancy that strikes 16,000 women and claims 4,900 lives each year.

Chlamydia, the nation's most common bacterial STD, is transmitted 4 million times annually, according to IOM. Yet 80 percent of the women infected-and 40 percent of the men-experience no initial symptoms and may unknowingly infect someone else. Because so many cases escape detection, 1 million infected women annually progress to pelvic inflammatory disease. The IOM report asserts that a moralistic approach to STDs-viewing them as symbols of sinful behavior-deters people from seeking information and treatment, "directly hindering" control efforts in the United States.