March 11, 2008
Preliminary CDC surveillance data indicate that the U.S. syphilis rate increased for the seventh consecutive year in 2007, largely reflecting continued syphilis increases among men who have sex with men (MSM). The syphilis rate among females also increased in 2007 for the third consecutive year, deepening concerns about a potential resurgence of the disease among women.
The new data include cases of primary and secondary (P&S) syphilis in 2007 reported to CDC from all 50 states. CDC researchers stress that the new figures are preliminary and that reporting delays and other factors could lead to small changes in the exact number of syphilis cases and rates as the data are finalized, but are confident in the overall trends. Final 2007 statistics will be published in CDCs annual STD Surveillance Report in late 2008.
Since 2000, when the national syphilis rate reached a low of 2.1 per 100,000, the rate has increased by 76 percent. The preliminary data indicate that the rate of P&S syphilis in 2007 was 3.7 cases per 100,000 population, a 12 percent increase from the rate of 3.3 per 100,000 in 2006. The number of cases increased from 9,756 in 2006 to 11,181 in 2007.
As in recent years, the overall increases in 2007 are largely among males. The preliminary data indicate that the rate for U.S. males in 2007 was 6.4 cases per 100,000 population, representing a 14 percent increase from the rate in 2006 (5.6) and a 146 percent increase from the rate in 2000 (2.6).
Several sources of data indicate that the trend in males largely reflects substantial increases among MSM since 2000. While syphilis rates have increased recently for both men and women, the increases have been considerably larger for men. The rate among men in 2007 was roughly six times higher than that among women. This differs from the pattern seen in the late 1990s when rates among males and rates among females were roughly equivalent. CDC data show that approximately 60 percent of all P&S syphilis cases in 2007 were among MSM, compared to an estimated 5 percent in 1999.
While MSM remain most affected by syphilis, the preliminary 2007 data indicate that the rate among U.S. females increased 10 percent between 2006 and 2007 (from 1.0 to 1.1 cases per 100,000), and increased 37 percent since 2004. The upward trend among females since 2004 follows more than a decade of syphilis declines among women. While the reasons for increases among women are not yet clear, CDC is analyzing the available data to determine potential factors behind the trend.
Rates among African American men and women remain higher than rates among whites -- six times higher for African American men and 13 times higher for African American women. Rates among African American men have increased 25 percent in the past year and 99 percent since 2003. Rates among African American women have increased 12 percent in the past year and 31 percent since 2003.
Since 1999, CDC has been working with public health and community partners on national syphilis elimination efforts aimed at curtailing the sustained transmission of syphilis in the United States. In May 2006, CDC issued an updated National Plan to Eliminate Syphilis, which is designed to sustain the major progress made since the early 1990s in populations traditionally at risk, including African Americans and women of all races, and to support innovative solutions to fight the resurgence of syphilis among MSM. More information on these efforts is available online at: http://www.cdc.gov/stopsyphilis/.
Symposium Abstract A6b -- Syphilis in the United States: Epidemiology and Emerging Issues. In: 2008 National STD Prevention Conference, Chicago, Ill., March 10-13, 2008.