Men who have sex with men (MSM) significantly contribute to the rising national rate of syphilis, the U.S. Centers for Disease Control and Prevention (CDC) estimated in their annual report, “Sexually Transmitted Disease Surveillance 2004.” Released on Nov. 8, the report estimated that MSM comprised 64 percent of the primary and secondary (P&S) syphilis cases in 2004, up from 5 percent in 1999. The P&S syphilis rate increased from 2.5 cases per 100,000 people in 2003 to 2.7 cases in 2004, the CDC reported.

Although the CDC has not collected data by risk group until recently, the male-to-female ratio for P&S syphilis cases has risen steadily between 2000 and 2004 (1.5 to 5.9), suggesting increased syphilis transmission among MSM.

“We have very good and sound information showing that since the late 1990s we’ve seen an increase in risky sexual behaviors among men who have sex with men,” said Ronald Valdiserri, acting director of the CDC’s National Center for HIV, STD and TB Prevention.

Valdiserri noted that in several communities, particularly on the West Coast but more recently on the East Coast, epidemics in crystal methamphetamine use among MSM are intersecting and are exacerbating the transmission of syphilis. Education about how to contract syphilis is one of the keys to curbing the epidemic, he said.

“We have seen that in some communities, sexually active MSM do not have adequate information about risk practices, specifically men are often surprised that syphilis can be transmitted through oral sex,” Valdiserri said. “There are a number of reasons that can help explain why among MSM we’re seeing higher rates of syphilis.

John Douglas, director of the Division of STD Prevention at CDC’s National Center for HIV, STD and TB Prevention, said Internet use most likely has a lot to do with increasing syphilis rates after 2000 as well as other STD infections.

“The increased rate of partnering or meeting sexual partners through the Internet has created a really mobile and broadly networked way of having [sexual] contacts, which are often incredibly anonymous,” he said.

Since 2000, when the P&S syphilis rate reached an all-time low in the U.S., the CDC has documented an increase every year since. The CDC report stated the increase is largely due to increases specifically among men, as their P&S syphilis rate increased 81 percent since 2000 and 11.9 percent from 2003 to 2004.

It hasn’t been all bad news however. Despite the recent increases among MSM, the CDC has made substantial progress in populations such as women and minorities that historically have been hardest hit by syphilis, Douglas noted.

“This progress is partly the result of CDC’s national plan to eliminate syphilis, which was launched in 1999. The rate among women decreased 55 percent from 1999 to 2004,” Douglas said.

According to the San Diego Health and Human Services Agency’s Division of STD and Hepatitis Prevention, a P&S syphilis rate of 4.5 was documented in San Diego in 2004, representing 136 cases. The rate increased from 3.7 in 2003. 2000’s rate was much lower at 1.0.

Robert Gunn, STD control officer for San Diego County’s Health and Human Services Agency, said San Diego most likely has surpassed 2004’s rate with 212 cases estimated for 2005, representing a 56 percent increase from last year.

Gunn noted in 2002, syphilis rates started to rise in San Diego County most likely due to cases trickling down from cities like Seattle, San Francisco and Los Angeles in the late ‘90s.

He attributed the syphilis rate increase to more and more HIV-positive men having unprotected sex with each other since Highly Active Anti-Retroviral Therapy (HAART) medications have become available.

“They’re doing unprotected sex because they figure they got HIV. ‘[They say] so what’s the big deal? What can I get now?’” Gunn said.

Some can transmit a rare form of syphilis called acute neurosyphilis. Although not very common, it can leave a person with a permanent disability such as blindness, a stroke or a hearing loss, Gunn explained.

The CDC report revealed that San Francisco had the highest reported rate of P&S syphilis with 45.9 cases per 100,000 people. Atlanta (34.6), Baltimore (33.2), New Orleans (16.4) and St. Louis (14.1) rounded out the top five cities.

Chlamydia, gonorrhea and syphilis are the three most reportable STDs in the U.S., according to the CDC, and all significantly increase the rate of HIV transmission.

The CDC states Chlamydia is the most commonly reported infectious disease. Its rates continue to increase, but the rise is most likely due to the continued expansion of screening efforts, and increased use of more sensitive diagnostic tests. The national rate of reported Chlamydia in 2004 climbed to 319.6 cases per 100,000 people – a 5.9 percent increase from 2003’s rate of 301.7.

Chlamydia rates in San Diego in 2004 were higher than the national average with 358.7 cases per 100,000 people. 2003’s rate was 346.1.

Gonorrhea, the second most commonly reported infectious disease in the U.S, reached an all-time low in 2004, falling 1.5 percent between 2003 and 2004 (115.2 cases to 113.5 cases per 100,000), according to the CDC report.

The gonorrhea rate in San Diego was lower than the national average at 78.7, but increased from 2003’s 66.6 rate.

Despite the national gonorrhea rate decrease, challenges still remain to eradicate the disease.

The CDC conducted research in 28 cities which found an increase in gonorrhea cases that were resistant to fluoroquinolone antibiotics, the first-line treatment for the infection. The resistant rate increased from 4.1 percent in 2003 to 6.8 percent in 2004. In MSM, the increase in resistance was eight times higher than among heterosexuals (23.8 percent compared to 2.9 percent).

Valdiserri said one of the major priorities at the CDC is to continue the fight against syphilis, particularly among the MSM community, while maintaining the progress made in historically impacted populations such as African-Americans and women.

“When it comes to reducing syphilis among MSM, there is no simple solution. However, innovative screening and prevention programs for MSM around the country are having an impact and are providing crucial lessons to help inform our future efforts,” said Validserri, who added since 2003 the CDC has partnered with health departments and community groups in cities with the highest syphilis rates to implement new syphilis prevention strategies for MSM.

For more information about getting tested for syphilis or any STD, call the San Diego County STD clinic at (619) 692-8550.