BACKGROUND: The most recent estimates of the number of prevalent and incident sexually transmitted infections (STIs) in the United States (US) were for 2008. We provide updated estimates for 2018 using new methods. METHODS: We estimated the total number of prevalent and incident infections in the US for eight STIs: chlamydia, gonorrhea, trichomoniasis, syphilis, genital herpes, human papillomavirus (HPV), sexually transmitted hepatitis B, and sexually transmitted HIV. Updated per capita prevalence and incidence estimates for each STI were multiplied by the 2018 full resident population estimates to calculate the number of prevalent and incident infections. STI-specific estimates were combined to generate estimates of the total number of prevalent and incident STIs overall, and by gender and age group. Primary estimates are represented by medians and uncertainty intervals are represented by the 25th (Q1) and 75th (Q3) percentiles of the empirical frequency distributions of prevalence and incidence for each STI. RESULTS: In 2018, there were an estimated 67.6 (Q1=66.6, Q3=68.7) million prevalent and 26.2 (Q1=24.0, Q3=28.7) million incident STIs in the US. Chlamydia, trichomoniasis, genital herpes, and HPV comprised 97.6% of all prevalent and 93.1% of all incident STIs. Persons aged 15-24 years comprised 18.6% (12.6 million) of all prevalent infections; however, they comprised 45.5% (11.9 million) of all incident infections. CONCLUSIONS: The burden of STIs in the US is high. Almost half of incident STIs occurred in persons aged 15-24 years in 2018. Focusing on this population should be considered essential for national STI prevention efforts.

The vaginal microbiota has great significance in maintaining vaginal health and protecting the host from disease. Recent advances in molecular techniques and informatics allow researchers to explore microbial composition in detail and to compare the structure of vaginal microbial communities with behavior and health outcomes, particularly acquisition and transmission of sexually transmitted diseases (STDs) and poor birth outcomes. Vaginal flora have been found to cluster into a limited number of communities, although community structure is dynamic. Certain community types are more associated with poor reproductive outcomes and STDs; communities dominated by Lactobacillus species, particularly Lactobacillus crispatus, are most associated with vaginal health. Modifiable and nonmodifiable factors are strongly associated with community composition, including behavior, race or ethnicity, and hygiene. In this review, we describe the state of the science on the vaginal microbiome and its relationship to behavior, sexual health, and STDs, including determinants of the microbiome that go beyond an individual level.

School-based sexually transmitted disease (STD) screening (SBSS) was designed to provide chlamydia and gonorrhea testing, treatment, and counseling to adolescents in a school setting to overcome some of the difficulties of screening in this population. To inform STD control programs and other entities on decision making about potentially implementing this intervention, we reviewed existing published and gray literature on SBSS from 1998 to 2014. Although they are work-intensive to establish, school-based STD screening programs are a feasible and cost-effective way of testing large numbers of male and female adolescents for chlamydia and gonorrhea, and to provide counseling and treatment to almost all those who are found infected. School-based STD screening programs do not seem to reduce prevalence in either the school or the general adolescent population, although there are currently relatively few studies on large-scale SBSS. More research in this field is needed.

BACKGROUND: From 2003 to 2012, the Philadelphia High School STD Screening Program screened 126,053 students, identifying 8089 Chlamydia trachomatis (CT)/Neisseria gonorrhoeae (GC) infections. We examined sociodemographic and behavioral factors associated with CT/GC diagnoses among a sample of this high-risk population. METHODS: Standardized interviews were given to infected students receiving in-school CT/GC treatment (2009-2012) and to uninfected students calling for results (2011-2012). Sex-stratified multivariable logistic models were created to examine factors independently associated with a CT/GC diagnosis. A simple risk index was developed using variables significant on multivariable analysis. RESULTS: A total of 1489 positive and 318 negative students were interviewed. Independent factors associated with a GC/CT diagnosis among females were black race (adjusted odds ratio [AOR], 2.27; confidence interval, 1.12-4.58), history of arrest (AOR, 2.26; 1.22-4.21), higher partner number (AOR, 1.75; 1.05-2.91), meeting partners in own neighborhood (AOR, 1.92; 1.29-2.86), and meeting partners in venues other than own school, neighborhood, or through friends ("all other"; AOR, 9.44; 3.70-24.09). For males, factors included early sexual debut (AOR, 1.99; 1.21-3.26) and meeting partners at "all other" venues (AOR, 2.76; 1.2-6.4); meeting through friends was protective (AOR, 0.63; 0.41-0.96). Meeting partners at own school was protective for both sexes (males: AOR, 0.33; 0.20-0.55; females: AOR, 0.65; 0.44-0.96). CONCLUSIONS: Although factors associated with a GC/CT infection differed between males and females in our sample, partner meeting place was associated with infection for both sexes. School-based screening programs could use this information to target high-risk students for effective interventions.

BACKGROUND: Targeted partner notification (PN), or limiting PN to groups in which efforts are most successful, has been suggested as a potentially cost-effective alternative to providing PN for all syphilis case-patients. The purpose of this study was to identify index case characteristics associated with highest yield partner elicitation and subsequent case finding to determine whether some groups could be reasonably excluded from PN efforts. METHODS: We examined index case characteristics and PN metrics from syphilis case management records of 4 sexually transmitted disease control programs-New York City, Philadelphia, Texas, and Virginia. Partner elicitation was considered successful when a case-patient named 1 or more partners during interview. Case finding was considered successful when a case-patient had 1 or more partners who were tested and had serologic evidence of syphilis exposure. Associations between case characteristics and proportion of pursued case-patients with successful partner elicitation and case finding were evaluated using chi tests. RESULTS: Successful partner elicitation and new case finding was most likely for index case-patients who were younger and diagnosed at public sexually transmitted disease clinics. However, most characteristics of index case-patients were related to success at only a few sites, or varied in the direction of the relationship by site. Other than late latent case-patients, few demographic groups had a yield far below average. CONCLUSIONS: If implemented, targeted PN will require site-specific data. Sites may consider eliminating PN for late latent case-patients. The lack of demographic groups with a below average yield suggests that sites should not exclude other groups from PN.

BACKGROUND: Screening for syphilis has been performed for decades, but it is unclear if the practice yields many cases at acceptable cost, and if so, at which venues. We attempted a retrospective study to determine the costs, yield, and feasibility of analyzing health department-funded syphilis outreach screening in 5 diverse US sites with significant disease burdens. METHODS: Data (venue, costs, number of tests, reactive tests, new diagnoses) from 2000 to 2007 were collected for screening efforts funded by public health departments from Philadelphia; New York City; Washington, District of Columbia; Maricopa County, Arizona (Phoenix); and the state of Florida. Crude cost per new case was calculated. RESULTS: Screening was conducted in multiple venues including jails, shelters, clubs, bars, and mobile vans. Over the study period, approximately 926,258 tests were performed and 4,671 new syphilis cases were confirmed, of which 225 were primary and secondary, and 688 were early latent or high-titer late latent. Jail intake screening consistently identified the largest numbers of new cases (including 67.6% of early and high-titer late-latent cases) at a cost per case ranging from $144 to $3,454. Data quality from other venues varied greatly between sites and was often poor. CONCLUSIONS: Though the yield of jail intake screening was good, poor data quality, particularly cost data, precluded accurate cost/yield comparisons at other venues. Few cases of infectious syphilis were identified through outreach screening at any venue. Health departments should routinely collect all cost and testing data for screening efforts so that their yield can be evaluated.

BACKGROUND: In 2008, an increase in syphilis among young black men was noted in New York City (NYC), Miami-Fort Lauderdale, and Philadelphia. To explore this trend, we examined infectious syphilis cases from 2000 to 2008 among adolescent and young adult men in these areas. METHODS: Descriptive analysis of male infectious syphilis cases reported to public health authorities in NYC, FL, and Philadelphia. RESULTS: From 2000 to 2008, infectious syphilis cases among males increased in NYC (107-1027 cases), Miami-Fort Lauderdale (109-374), and Philadelphia (41-142). This increase was largely attributable to cases among men who have sex with men. Rates among black adolescent males (15-19 years) increased in NYC ([2.6-43.0]/100,000), Miami-Fort Lauderdale ([5.5-48.1]/100,000), and Philadelphia (]8.3-40.3]/100,000). Among males with infectious syphilis in 2008 in NYC, 9.1% of blacks and 6.6% of Hispanics were adolescents compared with 1.6% of whites (P < 0.001). In Miami-Fort Lauderdale, 12.2% of black males were adolescents compared to 2.0% of whites (P < 0.01) and 2.7% of Hispanics (P < 0.01). Black males dominated all age groups in Philadelphia, but were more likely to be <25 years of age than whites (P = 0.02). Human immunodeficiency virus coinfection rates were 14.8% among adolescent males in NYC, 15.4% in Philadelphia, and 25.0% in Miami-Fort Lauderdale. CONCLUSIONS: Very young black males have emerged as a risk group for syphilis in these 3 areas, as have young Hispanic males in NYC. Many are men who have sex with men and some are already human immunodeficiency virus-infected. Targeted risk reduction interventions for these populations are critical.