May 12, 2014
2 min read

Syphilis rate in US more than doubled since 2000

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The rate of reported primary and secondary syphilis in the United States in 2013 was more than double the lowest rate ever in 2000, according CDC researchers.

As of April 28, the reported data for 2013 indicate a rate of 5.3 cases per 100,000 population. In 2000, the rate was 2.1 per 100,000. In 2005, the rate was 2.9 cases per 100,000, according to the MMWR report.

The researchers used data from the National Notifiable Diseases Surveillance System to evaluate trends in syphilis from 2005 to 2013. In 2005, the number of cases reported was 8,724, which nearly doubled to 16,663 cases in 2013. Men accounted for 91.1% of all primary and secondary syphilis cases in 2013. The rate of syphilis among men increased from 5.1 per 100,000 in 2005 to 9.8 per 100,000 in 2013. The proportion of male cases attributed to men who have sex with men increased from 77% in 2009 to 83.9% in 2012.

From 2005 to 2009, rate increases among men were highest among black men, who saw an increase of 104.1%. From 2009 to 2013, rates increased among Hispanic men by 52.6% and among white men by 45.9%, but decreased 6.4% among black men. By age, the same birth cohort had the highest rate increases: Men aged 20 to 24 years had a 149.4% rate increase from 2005 to 2009 and men aged 25 to 29 years had a 48.4% rate increase from 2009 to 2013.

Among women, the rate of primary and secondary syphilis increased from 0.9 per 100,000 population in 2005 to 1.5 per 100,000 in 2008, but decreased to 0.9 per 100,000 in 2013. The fluctuation is attributed to changing rates among black women, from 4.2 per 100,000 in 2005 to 7.9 per 100,000 in 2009 to four per 100,000 in 2013. Rates among white and Hispanic women were stable. The rates were similar across all age groups.

In 2013, the syphilis rate among black men was 5.2 times higher than that of white men, and the rate among black women was 13.3 times higher than that of white women. Hispanics also were disproportionately affected. The rate among Hispanic men was 2.1 times higher than that among white men, and the rate among Hispanic women was 2.7 times higher than that of white women. These disparities were similar in 2005.

“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 researchers wrote. “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.”

Disclosure: The researchers report no relevant financial disclosures.