Background/introduction Current clinic policy is to offer extra-genital testing to all patients reporting a history of active oral sex and/or receptive anal sex. These swabs are analysed using the Aptima Combo II platform for Chlamydia trachomatis (CT).

Aim(s)/objectives With analysis costing £6.20 per swab we sought to explore the cost effectiveness and review positive case with collateral contact information and symptoms history to support a positive diagnosis.

Methods Inclusion criteria were heterosexual patients with exclusively extra-genital CT who did not present as CT contact. We performed retrospective case note review of 63 sets of notes to determine symptom history, concurrent STI diagnosis and contact diagnosis.

Results Over the year, a total of 12076 throat swabs were sent in this group. There were 39 confirmed positive results giving swabs sent per positive result ratio of 310:1. Or a cost of £1922 per positive result. For rectal swabs; a total of 1156 were sent. There were 24 positive results giving swabs sent per positive result ratio of 48:1, or a cost of £297.60 per positive result. 5% of patients with a positive extra-genital swab result gave a history of throat or rectal symptoms. 4% had a concurrent STI diagnosis, 40% of those with traceable contacts had at least one positive contact.

Discussion/conclusion Routine extra-genital screening is costly but this review demonstrates its value for detection of individual cases which would have been missed. In addition the high proportion of positive contacts adds weight to the debate for extra-genital testing of all contacts.