Background:
Sex with partners found through the Internet has been implicated as a risk for sexually transmitted infections (STI). However, there are few studies that have evaluated this behavior in direct relation to the presence of STI.

Objective:
To assess the association between reporting recent sex with Internet partners and Chlamydia trachomatis (Ct) and Neisseria gonorrhoeae (GC) infections.

Method:
Between August 2006 and September 2007, patients at the Denver Metro Health (STD) Clinic were routinely asked about sexual encounters with Internet partners. The study was limited to patients who tested for either Ct or GC at their visit. Analyses were stratified by sexual orientation to account for differences in baseline risk behaviors.

Result:
Of 14,374 patients tested for Ct/GC, 2,321 (16.1%) tested positive for either infection. The odds ratio (OR) for Ct/GC infection among those reporting an Internet partner in the previous 12 months was 0.7 (95% CI: 0.6, 0.8). Stratified by sexual orientation, ORs were 1.0 (95% CI: 0.8, 1.4) for men having sex with men, 0.5 (95% CI: 0.3, 0.7) for men having sex with women (MSW), and 0.7 (0.3, 1.3) for women. Use of condoms (at last sex with non-main partners) was associated with a lower risk for Ct/GC (OR 0.8; 95% CI: 0.7, 0.9). Having Internet sex partners was associated with condom use (OR 2.5; 95 CI: 2.2, 2.9), but only 27% of those with Internet partners reported condom use.

Conclusion:
Sexual encounters with partners met on the Internet may not be as risky as previously thought and may be protective in some groups, particularly MSW. Higher condom use among patients with Internet partners may explain part of this protective effect, but overall condom use was low in this population.

Implications:
Further research is needed to understand the nature of internet sexual partnerships.