To describe the serologic test for syphilis (STS) prevalence among STD clinic clients, determine the correlation between STS prevalence trends and reported community-diagnosed primary and secondary (P&S) case incidence, and evaluate the usefulness of STS prevalence monitoring as a component of syphilis surveillance.
During the period 1985–2004, 21,4336 STS were done among STD clinic clients and a variety of STS prevalence measures were evaluated.
From 1985–1991, 10.2% of STS were positive, which declined to 5.6% during 1992–2004. Overall, STS positivity (≥1:8) and male positivity (≥1:8) trends were correlated with reported community-diagnosed P&S case incidence and case incidence in men (r = 0.58 and r = 0.81, respectively). Male STS positivity (≥1:8) began increasing in 2001, 1 year before the increase in syphilis incidence in men, which began in the latter half of 2002 and occurred mostly among men who have sex with men.
In a syphilis outbreak in men who have sex with men, STS prevalence (≥1:8) among male STD clinic clients was a useful measure of syphilis case incidence trends and may provide an early warning for a subsequent increase in community-diagnosed case incidence.
Temporal trends in syphilis serologic test positivity (≥1:8) among STD clinic clients were correlated with reported community-diagnosed primary and secondary syphilis incidence. Routine STS monitoring may help predict changes in case incidence.
From the *Division of STD Prevention, Centers for Disease Control and Prevention, Atlanta, Georgia; †Public Health Services, HIV, STD, and Hepatitis Branch, Health and Human Services Agency, San Diego, California; and ‡Graduate School of Public Health, San Diego State University, San Diego, California
The authors thank Rita Perry and Jody Thomas for manuscript preparation and Thomas Peterman, MD, Richard Kahn, MPH, and Akbar Zaidi, PhD, for helpful suggestions.
This program evaluation was supported in part by an appointment (Dr. Gunn) to the research participation program at the Centers for Disease Control and Prevention (CDC) administered by the Oak Ridge Institute for Science and Education through an interagency agreement between the US Department of Energy and CDC.
Correspondence: Robert A. Gunn, MD, MPH, STD Control Officer, HIV, STD and Hepatitis Branch, 3851 Rosecrans St (P501C), San Diego, CA 92110. E-mail: email@example.com.
Received for publication November 27, 2006, and accepted January 31, 2007.