Rate of infection overall up 12 percent, is higher in men than in women
The number of new cases of primary and secondary syphilis increased to 11,181 in 2007, a 12 percent increase over the previous year, according to preliminary data, according to information released by the Centers for Disease Control and Prevention at a Wednesday, March 12 news conference at the 2008 National STD Prevention Conference in Chicago.
The rate of syphilis infection in men is six times that of women, and 64 percent of the male infections are in men who have sex with men (MSM). Men who are infected with HIV and are on therapy constitute a significant portion of those infections, historically, about half in some cities, according to the CDC report.
Hilliard Weinstock with the CDC’s division of STD prevention, said this "presents a major concern for the health of MSM" because co-infection with syphilis "can increase the likelihood of HIV transmission two to five-fold."
"For individuals already infected with HIV, syphilis can increase viral load, which can accelerate HIV disease progression," she said, adding that co-infection also can result in more rapid progression of syphilis, particularly within the brain, where it can result in blindness and dementia if left untreated.
John Douglas, director of STD prevention at the CDC, said part of the increase in syphilis among HIV-positive gay men may be due to their attitude.
"They have already taken the big hit of getting a fatal disease and have survived it, there is the potential of seeing other STDs as a nuisance," he said.
The CDC recommends that sexually active gay men be screened at least once a year for all sexually transmitted diseases, and high-risk individuals should be tested even more frequently. Those tests should include ones for syphilis, Chlamydia and gonorrhea in the penis, rectum and throat.
A gonorrhea infection in the urethra of the penis often is painful and so the person goes to a doctor for treatment, CDC officials noted, but infection in the throat or rectum often is asymptomatic or the symptoms are so mild that they are easily ignored.
One study presented at the conference found that a third of all rectal gonorrhea infections and a quarter of those in the throats of MSM were not identified or treated because those anatomic sites were not tested. Another study looked at data from more than 10,000 HIV-negative MSM and found that only 39 percent were tested for syphilis and 36 percent were tested for gonorrhea at any site.
Douglas called regular screening for these STDs "one of our best tools for insuring prompt diagnosis and treatment and slowing the transmission of these diseases." He said these studies reinforced the need for increased screening among gay men.
Gonorrhea and chlamydia traditionally are identified using a culture test that takes several days to produce results. A more advanced laboratory test that identifies the DNA of the bacteria is more accurate and gives quicker results than the traditional culture plates. However, it is only certified for use with urethral samples.
Once the company got approval for use of the DNA test with urethral samples it decided that the market was not big enough to justify funding rectal and oral trials to verify that the tests work there as well, said Julius Schachtner, a researcher at the University of California San Francisco.
He said academic researchers have conducted small trials and have found that DNA tests are about twice as accurate as cultures at diagnosing infections in the throat or rectum. The CDC and public health departments are working with the FDA to try to get a broader approval for use of the DNA tests.
Douglas acknowledged that public health resources are tight at the national, state and local levels. However, he noted that many gay men have private health insurance and should have access to regular health care. There is a failure of physicians to conduct recommended annual screening for STDs, and of patients to demand them, he said.
He said it is "part of a larger national fabric of difficulty talking about sex," and that he sees "a need to address the reality of sexuality in the population."
Part of the solution is greater "cultural competency" of physicians in working with their gay patients," Douglas said.
This article appeared in the Dallas Voice print edition March 14, 2008