Predictors of New STI Acquisition in the 5 Years Post-DIS Interview

Background: Houston/Harris County has the highest number of cases of HIV, Chlamydia, gonorrhea, and syphilis of any county in Texas. In order to better inform prevention activities, the Houston Department of Health and Human Services (HDHHS) recently examined surveillance data for evidence of re-infections and the predictors of an additional morbidity.

Objectives: To determine the frequency and predictors of new STI acquisition in the 5 year time period following an interview with a Disease Intervention Specialist (DIS) in Houston/Harris County, Texas.

Methods: Interview and morbidity data from the STD*MIS were analyzed for clients with a syphilis and/or HIV interview date between 2000 and 2005. Client records were examined for 5 years past the date of interview to assess acquisition of a new STI (follow-up time period from 2005 to 2010). Logistic regression models were created in SAS and STATA to assess significance of demographic and risk information to predict STI re-infection.

Results: Of 6,112 clients interviewed for HIV (22.6%), syphilis (74.1%), or HIV and syphilis (3.3%), 87.6% did not have another STI diagnosed and reported in the 5 year time period following the date of interview. Significant predictors (P<0.05) of an additional STI morbidity were race/ethnicity and age at time of interview.

Conclusions: Analysis revealed that the vast majority of Houston/Harris Co. clients did not have another STI diagnosed and reported to HDHHS in the five years following a DIS interview for syphilis or HIV.

Implications for Programs, Policy, and Research: With nationwide Chlamydia and syphilis rates increasing as public health funds dwindle, many health departments are faced with difficult decisions as to what services should be prioritized. A review of frequency and predictors of re-infections provides a quantitative context to public health prevention and follow-up activities.