Caitlin F. Gill Indiana University School of Medicine, Department of Public Health

1. Use of Surveillance Data to Identify the Most Effective Case-Detection Method(s) for Identifying Early Syphilis Cases atHigh-Risk for Transmission Caitlin F. Gill Indiana University School of Medicine, Department of Public Health Master of Public Health Program PBHL P704-Epidemiology-Final Concentration Project December 8th, 2011 IRB Study Number: 1106006120

2. Background/Rationale • Rates of infectious syphilis have increased in the USA during the past 10 years. • A small group of syphilis cases, “core transmitters” are responsible for disease burden in a community. • Determining the most effective case detection method to identify these cases can be invaluable to decreasing disease rates. Kahn et al., 2006; Koumans et al., 2001; Bernstein et al., 2004

3. Study Aims • Determine the proportion of syphilis cases at high risk for transmissiondetected by each of the four case detection methods among the cases at Bell Flower Clinic reported from January 2008 through December 2010. • Assess differences in characteristics of those at high risk of transmission compared to the other early syphilis cases.

4. Study Design • Cross-Sectional Study • Dependent Variable: High-Risk of transmitting the disease. • Independent Variables: Stage of infection, method of case detection, number of sex partners during the past 12 months, demographics and high-risk behaviors

5. Study Population • Description: Primary, secondary or early-latent syphilis subjects diagnosed between January 1, 2008 through December 31st, 2010 at the Bell Flower Clinic located in Marion County, Indiana. • Size: All subjects (n= 379) identified by one of the following methods of case detection.

6. Case Detection Methods • Disease Intervention Specialist (DIS): A staff member trained to treat, interview and follow up persons diagnosed with a sexually transmitted disease (STD). • Patient Referral: Patient referred by another STD infected person. This may be a named or unnamed partner. No health department involvement was needed for this referral. • Screening: An asymptomatic patient identified at initial evaluation conducted by a provider to determine whether a person is at risk for or has a STD. • Self-Referral: A patient who sought health services due to signs of a STD and was tested for the disease being reported.

7. Operational Definition of Variables • Syphilis: A sexually transmitted disease (STD) caused by the bacterium Treponema pallidum. • Primary Syphilis: Serum specimens with a nontreponemal rapid plasma reagin (RPR) fourfold rise in titer or a reactive FTA test. • Secondary Syphilis: Presence of characteristic dermatologic lesions and a reactive nontreponemal RPR test (titer > 1:16). • Early-latent Syphilis: After the primary and secondary phases have subsided, during the first year after infection, before any manifestations of tertiary syphilis have appeared. Centers for Disease Control and Prevention, 1997

8. Operational Definition of “High Risk” • High-Risk Cases (n= 84):

9. Data Source and Data Gathering Information • Data extraction from Sexually Transmitted Disease Management System (STD*MIS) and the Statewide Information Management Surveillance System (SWIMSS) database. • Included: Syphilis interview records and morbidity data from January 2008 through December 2010.

10. Other Data Gathered • Demographic elements- Sex, Age, Race/Ethnicity, etc. • Case management data- Patient identification number, method of case detection, number of sex partners, sexual orientation, etc. • Locally defined variables- History of incarceration in past 3 or 12 months, substance abuse, sex with an anonymous partner, sex while high and sex with an injection drug user (IDU).

11. Data Analysis • Descriptive statistics were assessed for all variables. • Chi-square statistics used to compare: • Race/ethnicity and case characteristics. • Method of case detection and case characteristics • High and low risk and case characteristics

14. Discussion • Strengths: • Sample size (All subjects n= 379) • Examined many factors at one time • Limitations: • Previously collected self-reported data • Can’t determine the time sequence between exposure and outcome • Data entry errors/ missing data • Non-response of subjects for particular variables • Observation bias resulting in misclassification: overlap of primary and secondary stage features of syphilis and reporting of false-negative serology in both primary and less commonly in secondary syphilis

15. Conclusion • Case detection methods vary in their ability to identify high-risk transmission subjects. • Screening and Self-referral were the two methods of case detection which identified the highest proportion of high-risk individuals. • Continue to: • screen high risk groups (MSM, incarcerated, commercial sex workers) • quickly bring cases in for treatment

16. Future Research • Conduct similar evaluations of syphilis prevention activities. • Look at the individual characteristics of high-risk cases identified by each method of case detection and determine if there is a commonality among those subjects.

17. Acknowledgement A special thank you to: • Jutieh Lincoln, MPH (Marion County Public Health Department, Epidemiology) • Janet N. Arno, M.D. (Marion County Public Health Department , Infectious Disease) • Terrell W. Zollinger, Dr. P.H. (Indiana University Department of Public Health)

18. Questions?