Background:
Behavioral interventions among adolescents have yielded mixed results and have been difficult to sustain. Sexual risk behaviors and history of sexually transmitted infections (STIs) have been individually associated with socio-economic status, child abuse and partner violence. Current STI has been associated with history of abuse and depression in subpopulations.

Objective:
Determine the association of individual ecosocial conditions (low income, housing insecurity, childhood abuse, violence, alcohol & drug use, depression) with prevalent STI and traditional behavioral risk factors; determine if multiple ecosocial factors compounds risk.

Method:
Young adults ages 18-27 participating in the National Longitudinal Study of Adolescent Health (Wave III; n=14,322) provided data on ecosocial conditions, individual behavioral risk factors, and history of STI. First-void urine was tested for C. trachomatis (CT) and N. gonorrhoeae (GC) using LCR, and T. vaginalis (TV) and M. genitalium (MG) using PCR.

Result:
Housing insecurity (AOR=1.3 [1.00-1.72]), exposure to violence (AOR=1.4 [1.02-1.80]), and having ever been arrested (AOR=1.4 [1.07-1.84]) were associated with prevalent STI (CT, GC, TV, or MG). As the number of ecosocial conditions increased, STI prevalence increased in a stepwise fashion from 4.9% for 0 factors to 16% for ≥ 4 factors (p<0.001). In addition to the three ecosocial factors above, having received welfare, childhood sexual abuse, gang participation, recent drug use and depression diagnosis were associated with increased sexual risk behavior (more lifetime partners and younger age at sexual debut; all comparisons p<0.05).

Conclusion:
Ecosocial factors, often present early in life before sexual debut, influence STI risk directly, as well as indirectly by increasing risky sexual behaviors, which in turn enhance STI risk.

Implications:
Interventions to change individual behaviors instead of comprehensive, integrated modifications to the person's environment may often be too little, too late. More research is needed to develop interventions that address upstream ecosocial conditions.