Camden J Hallmark1, Mandy J Hill, Charles Luswata, Kellie L Watkins, Lupita Thornton, Marlene McNeese, Michael W Ross. 1. From the *Department of Epidemiology, Human Genetics, and Environmental Sciences, School of Public Health, The University of Texas Health Science Center at Houston, Houston, TX; †Houston Health Department, Houston, TX; ‡Department of Emergency Medicine, McGovern Medical School, The University of Texas Health Science Center at Houston, Houston, TX, §Department of Biostatistics, School of Public Health, The University of Texas Health Science Center at Houston, Houston, TX; and ¶Program in Human Sexuality, Department of Family Medicine and Community Health, University of Minnesota, Minneapolis, MN.
Abstract
BACKGROUND: After reaching an all-time low in 2000, syphilis incidence in the United States has increased as the burden shifted from heterosexuals to men who have sex with men (MSM). Houston, Texas, experienced 2 outbreaks of syphilis during this transformation in trends. Further evaluation is necessary to determine if these outbreaks occurred among the same subpopulations. METHODS: Surveillance data collected on all reported infectious syphilis cases in Houston from 1971 to 2013 were analyzed. Trends in incidence among MSM and human immunodeficiency virus-positive Houston residents were examined. Peak syphilis years subsequent to 1999, years 2007 and 2012, were compared to determine if outbreaks arose in distinctive subpopulations. Categorical variables between these years were compared using chi-square and Fisher's exact tests, whereas further associations between the years were evaluated using multivariable logistic regression. RESULTS: Incidence among MSM was 20.9 to 32.1 times higher than other men from 2005 to 2013. After adjusting for covariates, cases in 2012 were significantly more likely to be Hispanic (adjusted odds ratio [AOR] = 1.61; 95% confidence interval [95% CI], 1.03-2.53), reported meeting partners via the Internet (AOR, 1.74; 95% CI, 1.18-2.58), and engaged in anonymous sex (AOR, 1.92; 95% CI, 1.40-2.63) in comparison to cases in 2007. CONCLUSIONS: We found marked disparities of syphilis by subpopulation in Houston. Herein, we present evidence that outbreaks have been distinct in a major southern city with a high burden of syphilis.
BACKGROUND: After reaching an all-time low in 2000, syphilis incidence in the United States has increased as the burden shifted from heterosexuals to men who have sex with men (MSM). Houston, Texas, experienced 2 outbreaks of syphilis during this transformation in trends. Further evaluation is necessary to determine if these outbreaks occurred among the same subpopulations. METHODS: Surveillance data collected on all reported infectious syphilis cases in Houston from 1971 to 2013 were analyzed. Trends in incidence among MSM and human immunodeficiency virus-positive Houston residents were examined. Peak syphilis years subsequent to 1999, years 2007 and 2012, were compared to determine if outbreaks arose in distinctive subpopulations. Categorical variables between these years were compared using chi-square and Fisher's exact tests, whereas further associations between the years were evaluated using multivariable logistic regression. RESULTS: Incidence among MSM was 20.9 to 32.1 times higher than other men from 2005 to 2013. After adjusting for covariates, cases in 2012 were significantly more likely to be Hispanic (adjusted odds ratio [AOR] = 1.61; 95% confidence interval [95% CI], 1.03-2.53), reported meeting partners via the Internet (AOR, 1.74; 95% CI, 1.18-2.58), and engaged in anonymous sex (AOR, 1.92; 95% CI, 1.40-2.63) in comparison to cases in 2007. CONCLUSIONS: We found marked disparities of syphilis by subpopulation in Houston. Herein, we present evidence that outbreaks have been distinct in a major southern city with a high burden of syphilis.