Syphilis Spike in 2012 'Troubling,' CDC Says

January 08, 2014

The number of cases of primary and secondary syphilis in the United States increased 11.1% in 2012 with men — particularly gay and bisexual men —accounting for the spike entirely, according to the latest surveillance report on sexually transmitted diseases (STDs) from the Centers for Disease Control and Prevention (CDC).

Published online today, the annual report contains other discouraging news about STDs, as well as a few bright spots. Gonorrhea posted a 4% increase in 2012, most of that among men. In contrast, the number of reported chlamydia cases grew by a mere 0.7% in 2012, the smallest annual increase since nationwide reporting on this STD began. As with syphilis, the rise in chlamydia cases was exclusively a guy thing.

The incidence of congenital syphilis decreased 10% in 2012 to 322 reported cases.

The CDC review concentrates on syphilis, chlamydia, and gonorrhea because other STDs, such as human papillomavirus infection, herpes simplex virus infection, and trichomoniasis, are not routinely reported to the CDC.

In an interview with Medscape Medical News, report coauthor and CDC epidemiologist Eloisa Llata, MD, said that turning STD upswings into downswings depends in part on clinicians adhering to screening recommendations from her agency and the US Preventive Services Task Force. That sometimes means asking questions about changes in a patient's sexual behavior — such as acquiring a new sexual partner.

"These are difficult conversations to have," said Dr. Llata. "It's easier to talk about diabetes. But we have to get past that. Sexual health is just as important to talk about as other aspects of health."

Syphilis and HIV: "A Twin Epidemic"

Dr. Llata stresses that while everyone is at risk of contracting an STD, some groups are at greater risk. For example, men who have sex with men (MSM) account for 75% of all primary and secondary syphilis cases, according to the agency. In 2012, the number of cases in this population increased 15% compared with 4% for men who have sex with women. The total number of primary and secondary syphilis cases in 2012 was 15,667.

The CDC calls the spike in syphilis infections in MSM "troubling," especially because this and other STDs can put an individual at a higher risk of acquiring or transmitting HIV infection.

The syphilis statistics also alarm Brad Stoner, MD, the president of the American Sexually Transmitted Diseases Association.

"It's a worrisome trend," said Dr. Stoner, an associate professor of medicine and anthropology at the Washington University School of Medicine in St. Louis, Missouri. "The absolute numbers are low, but the rate increase is high. And so many MSM with syphilis also have HIV. It's a twin epidemic."

According to CDC surveillance data collected in several major cities, 4 in 10 MSM with syphilis are infected with HIV as well.

The anxiety about syphilis has been building for years. The rate of primary and secondary syphilis declined by almost 90% from 1990 to 2000 only to rise each year from 2001 to 2009. The number of cases decreased in 2010 and then plateaued in 2011 before resuming an upward trajectory in 2012.

The risk for syphilis varies by race and ethnicity as well as by sex and sexual orientation. The rate of primary and secondary syphilis in blacks was 6 times that in whites in 2012. For blacks and whites aged 15 to 19 years, the difference was 16-fold.

Gonorrhea Gaining Antibiotic Resistance

For gonorrhea and chlamydia, the most widespread of the 3 STDs examined in the new report, the disease burden falls mostly on adolescents and young adults. Of the 1.4 million cases of chlamydia reported in 2012, 69% occurred in individuals 14 to 24 years of age. Likewise, this age demographic accounted for 58% of the nearly 335,000 cases of gonorrhea.

As with syphilis, Dr. Stoner said the increase in gonorrhea is discouraging.

"The national experience with gonorrhea is that it has plateaued since the mid-1990s and it's been creeping up intermittently since then," Dr. Stoner told Medscape Medical News. "We have another opportunity to do more detection and prevention."

The CDC noted that treating gonorrhea is problematic because antimicrobial resistance has lessened the effectiveness of fluoroquinolones and cefixime. The only treatment that the agency now recommends for gonorrhea is dual therapy with ceftriaxone and either azithromycin or doxycycline. And ceftriaxone could be the next victim of antimicrobial resistance.

Screening for STDs: Don't Assume Anything

Early detection plays a big role in keeping the lid on STDs. The CDC makes these screening recommendations:

  • Annual chlamydia screening of all sexually active women 25 years of age and younger, and older women with risk factors, such as new or multiple sex partners.

  • Annual gonorrhea screening for sexually active women with risk factors such as new or multiple sex partners, or living in communities with a high burden of disease.

  • Syphilis, chlamydia, HIV, and hepatitis B screening for pregnant women. At-risk pregnant women should undergo gonorrhea screening early in pregnancy, with the test repeated as needed to protect both mother and infant.

  • At least annual screening for syphilis, chlamydia, gonorrhea, and HIV for all sexually active MSM. Those with multiple or anonymous partners should be screened every 3 to 6 months. Also warranting more frequent tests are MSM who have sex in conjunction with illicit drug use by either partner.

Dr. Stoner said the guidelines omit heterosexual men because screening them flunks the government's cost-benefit test in a time of limited health dollars. "The cost per case detected is inordinately high," he said. "You'll screen a lot of at-risk men to find a few cases."

In contrast, screening women for STDs yields more cases at a lower cost, said Dr. Stoner. The reason? Women already are receiving routine gynecologic and obstetric services at physician offices, community health centers, and Planned Parenthood clinics, and it's just a matter of adding STD tests to the mix. In addition, public health authorities target women for STD screening because they "bear the brunt of long-term complications." These include infertility, ectopic pregnancies, and chronic pelvic pain.

The CDC report notes a marked improvement in testing women for chlamydia. From 2001 to 2011, this screening rate increased from 23.1% to 45% among sexually active women 16 to 24 years of age covered by commercial insurance plans. For those covered by Medicaid managed-care plans, the screening rate went from 40.4% to 58% during this period.

Dr. Stoner, however, sees room for improvement. One drag on screening rates for all STDs is the closure of STD clinics in urban areas because of tight public-health budgets. Another is the reluctance of many physicians to probe into a patient's sex life. "Doctors don't want to offend a patient by asking, 'Do you have a new partner?' " he said.

Some physicians erroneously assume that their patient's lifestyle does not match up to risk factors that call for STD screenings, said obstetrician-gynecologist Kevin Ault, MD, a professor of gynecological specialties at Emory University School of Medicine in Atlanta, Georgia.

"You think you don't have patients like that, with multiple sexual partners," Dr. Ault told Medscape Medical News, "[but] you start asking questions, and you find out you do have those patients after all."


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