Syphilis at All-Time Low; Other Sexual Diseases on Rise
U.S. syphilis rates reached an all-time low in 1999, suggesting that it may be possible to virtually eliminate the disease from the American scene, but gonorrhea rates reversed a two-decade trend by rising 9%, researchers from the Centers for Disease Control and Prevention said Tuesday.
The syphilis decline was the result of natural cycles of the disease and an aggressive federal program of testing and education. The gonorrhea increase was primarily the result of gay men’s returning to unsafe sexual practices in the belief that new AIDS treatments had lowered the risk of that deadly disease, said Dr. Ronald Valdiserri of CDC.
The syphilis data was the only good news in the CDC report, released at a conference in Milwaukee on prevention of sexually transmitted diseases. Chlamydia remains the most commonly reported STD in the country, with 660,000 new cases in 1999--but the actual number of new cases may be as high as 3 million per year, CDC researchers estimated.
Human papilloma virus infections have also been growing, with an estimated one in five Americans now infected.
“These new statistics are cause for serious concern,” said Dr. Helene Gayle, director of CDC’s National Center for HIV, STD and TB Prevention.
Gonorrhea and chlamydia are major causes of pelvic inflammatory disease in women, which can lead to infertility. Syphilis can cause mental illness and death if untreated.
Equally important, Valdiserri said, an STD increases the risk of contracting or transmitting HIV at least twofold, and perhaps as much as fivefold. But some recent studies have shown that as many as half of all gay men aren’t aware of the link between HIV and other STDs, he added.
Despite recent outbreaks of syphilis in Los Angeles and gonorrhea in San Francisco, California has one of the lowest rates of the two diseases in the country--probably because of an active public health program, Valdiserri said. The state has one of the highest rates of chlamydia infection, however.
The major concentrations of gonorrhea and syphilis are in the Southeast United States and in certain urban areas. Dr. Judith Wasserheit of CDC said half of all new cases of syphilis in 1999 occurred in just 25 of the nation’s 3,115 counties, and 75% occurred among African Americans.
“That is a direct result of poverty and inadequate access to health care,” Valdiserri said.
The high concentration of syphilis cases in a relatively small area is one reason researchers think they can stamp out the disease. Already, the incidence of congenital syphilis has been reduced by 48%, to 14.3 cases per 100,000 live births.
In contrast, federal efforts to control gonorrhea have fallen short, Valdiserri said, particularly in the gay community.
Dr. Cornelius Rietmeijer of the Denver Department of Public Health reported at the Milwaukee meeting, for example, that the incidence of gonorrhea among gay males visiting the Denver Metro Health Clinic had dropped to 5.4% in 1995, but surged to 12.8% in 1998. That increase was accompanied by a 50% increase in reported anal sexual contact, he said.
Similarly, Dr. H. Hunter Handsfield of the University of Washington said the incidence of gonorrhea among gay males in King County, Wash., more than doubled from 1997 to 1999.
The rise in gonorrhea rates, Gayle said, “should serve as a wake-up call . . . that high-risk sexual behaviors continue to have very real consequences.”
Chlamydia is an STD that can be easily treated and cured if caught, but it can lead to infertility and dangerous tubal pregnancies if left untreated. Although the number of reported cases is just under 660,000, officials believe that the true number is about five times as large. One reason for the discrepancy is that men rarely get tested for the disease, and at least half the men who contract it have no obvious symptoms.
“Screening for chlamydia can have a tremendous impact,” Wasserheit said. An aggressive program in the Pacific Northwest, for example, produced a 62% decline in chlamydia cases between 1988 and 1999, she said.
The new report also contains the first good data about the human papilloma virus, which is the most common STD among young sexually active people. Unlike the other STDs, data on papilloma infections is not required to be reported to CDC. But the agency estimates that at least 20 million Americans show evidence of having been infected by the virus and that another 5.5 million are infected each year.
There is no effective treatment for papilloma virus, and if the body does not clear an infection on its own, the virus produces a sharply increased risk of cervical, penile and anal cancers. An estimated 95% of women with cervical cancer have a papilloma virus infection.
Dr. Katherine Stone of CDC reported data at the Milwaukee conference on the incidence of HPV-16, just one of the 100 or so papilloma viruses that infect humans. She found that 17.9% of women were infected by the virus, compared with only 8% of men. African American women ages 20 to 29 had the highest exposure to the virus, with 36% of them having been infected. Overall, 19.1% of blacks were infected with the virus, compared with 12.5% of whites.
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Infection Rates, 1999
The highest rates of gonorrhea in the nation are concentrated in the Southeast.
Source: Centers for Disease Control and Prevention
