Syphilis Cases Doubled Between 2000 and 2013

Syphilis cases in the U.S. have increased significantly since the disease was nearly extinguished in 2000, particularly among men who have sex with men (MSM). In fact, the rate of primary and secondary syphilis in the U.S. has more than doubled from 2.1 cases per 100,000 people in 2000, to 5.3 cases per 100,000 in 2014, according to a Centers for Disease Control and Prevention (CDC) Morbidity and Mortality Weekly Report titled “Primary and Secondary Syphilis—United States, 2005-2013.”

Demographic Breakdown

Between 2005 and 2013, the number of reported primary and secondary syphilis cases doubled from 8,724 to 16,663. Men accounted for 91.1 percent of all primary and secondary cases, reflecting a rate increase from 5.1 percent of all men in 2005 to 9.8 percent in 2013. Further, male cases that were attributable to MSM increased from 77 percent in 2009, to 83.9 percent in 2012. However, among women, primary and secondary syphilis rates increased from 0.9 to 1.5 cases per 100,000 from 2005 through 2008, but decreased to 0.9 cases per 100,000 in 2013. The decrease in cases among women was mostly attributable to a drop in syphilis cases among black women.

Nevertheless, racial and ethnic disparities in syphilis cases persisted in 2013. Specifically, the primary and secondary syphilis rate among black men was 5.2 times more than white men, and the rate among black women was 13.3 times more than white women. In addition, the rate among Hispanic men was 2.1 times more than white men, and the rate among Hispanic women was 2.7 times more than white women.

Rates by Region

Primary and secondary syphilis rates increased among all four U.S. Census regions between 2005 and 2013. The West region had the highest overall regional rate in 2013, with 6.5 cases per 100,000 people. This marked the first time in over 50 years that the South did not have the highest rate of syphilis cases. For the most part, race and ethnicity rates among men and women mirrored national trends in the West Region.

CDC Response

“Despite decreasing rates of primary and secondary syphilis in the late 1990s in the United States, the resurgence of cases in recent years highlights the fact that challenges remain, and the increases among MSM are particularly concerning,” the CDC said. “Public health practitioners might want to consider focusing on efforts to strengthen linkages with practicing physicians to improve case identification and reporting, partner-notification programs, and outreach to MSM.”