Background Home-sampling is an increasingly used method to promote testing for Chlamydia trachomatis. Here, we implement and evaluate home-sampling for re-testing and peer-testing in young (<25 years) heterosexual men and women.

Methods At our STI clinics (Limburg, Netherlands, 2015–2018), indexes, i.e. young heterosexuals diagnosed with chlamydia, were (a) offered a self-sampling test for a peer, and (b) offered to receive an SMS-reminder after 5 months to order a re-test for themselves and a peer. Test offers were free-of-charge self-sampling tests for chlamydia and gonorrhea (urine sample for men; vaginal and rectal swabs for women). We interviewed care providers on implementation-barriers and facilitators and performed a process evaluation on test-uptake and overall (genital or rectal) STI positivity.

Results Of 1709 indexes (1221 women): (a) 571 (33.4%) were given a test for a peer; 211 (37.0%) peers tested and peer-positivity was 18.5% (17.9% in women-including 3 cases of gonorrhea and 12.8% rectal chlamydia; 19.5% in men). (b) 1048 (61.3%) accepted to receive a re-test reminder; 417 (39.8%) ordered the re-test and 266 (63.8%) re-tested with 13.9% re-test positivity (15.6% in women –including 10.4% rectal chlamydia–, 8.2% in men – including one gonorrhea case). 155/417 (37.2%) also ordered a peer-test; 62 (40%) peers tested but only 6.5% (n=4) were positive. In (a) and (b), nearly half of positive peers never tested before; rectal infections in women were frequently without a genital infection. Interviews with care-providers revealed problems in implementing logistics which could be solved by an easy-to-use online system.

Conclusion A future implementation using an online system needs to improve test-kit returns by including reminders or provisionary payment, and strategies to help indexes find and motivate high risk peers. High STI positivity in peers (many first time testers) from clinic-indexes reveals the need to especially target these peers to tap into a hidden (untested) infected population.

Disclosure No significant relationships.