Jail-Based Chlamydia Screen-and-Treat Programs and Community Prevalence: Is There a Potential Spill-Over Effect?

Background: People entering jails are at higher risk for sexually transmitted diseases (STDs) than the general population. Recent observational studies have suggested that jail-based STD screening programs can reduce the burden of disease in the communities they serve. However, there have been no controlled trials or other prospectively-designed studies to assess the impact of jail screening programs. 

Objectives: To explore the potential impact of a jail-based chlamydia screen-and-treat program on community prevalence in a hypothetical setting using a dynamic mathematical model. 

Methods: We used a deterministic population-based compartmental heterosexual transmission model for chlamydia in two locations (community and jail). We assumed two sexual activity classes for males and females (high and low). Parameter values were obtained from published literature. Events were modeled as arrestees moved from the community into jails, and inmates were released back into the community.

Results: A jail-based program with 50% screening coverage and 70% treatment of those testing positive could reduce chlamydia prevalence in the community by about 11.7% (from 2.08% prevalence to 1.81% prevalence) within two years of program onset. The burden of disease among those treated in jail would be reduced substantially as well. When setting three key parameters to their most extreme values in the model simultaneously (screening rate (90%), post-screening treatment rate (90%) and overall incarceration rate (0.9%)), the estimated reduction in chlamydia prevalence in the community was up to 43.0%.

Conclusions: Jail-based chlamydia screen-and-treat programs have the potential to reduce chlamydia prevalence in the community. Another major benefit of jail screening is that it provides an opportunity to screen the underserved, including men, who are typically unreachable.

Implications for Programs, Policy, and/or Research: Jail screening programs may play an important role in reducing community burden of chlamydia and should be considered as part of STD prevention and control efforts where possible.