Comparison of Self-taken Penile Meatal Swabs Versus First-catch Urine for the Detection of Chlamydia Trachomatis, Neisseria Gonorrhoeae and Mycoplasma Genitalium

Study Methods The study population will be men and transwomen aged 18 and over presenting to Leeds Sexual Health who wish to be tested for chlamydia, gonorrhoea and M. genitalium (if symptoms of urethritis are present). Those who have taken antibiotics (except metronidazole) in the past 14 days will be excluded. Details of age, ethnicity, past sexually transmitted infection (STI) history, being in contact with a STI and symptoms suggestive of a bacterial STI (urethral discharge, dysuria, testicular pain and swelling) will be collected. Prior to any examination by the clinician the participant will be asked to perform a self-taken penile meatal swab following the written and diagrammatic instructions for self-collected penile meatal swabs using the technique recommended by Hologic. Those with genital symptoms will be examined and the presence of urethral discharge and testicular swelling and tenderness will be recorded. A urethral swab for microscopy and gonococcal culture will be taken by the clinician if there is any evidence of urethral discharge. Those who have no genital symptoms will not be examined and will not have a urethral swab for microscopy or gonococcal culture taken as in routine clinical practice. All men will then be asked to perform a FCU sample. The penile meatal swab and FCU will be tested for M. genitalium if there are symptoms of urethritis. The first 500 participants will be asked to complete a short questionnaire of six questions on how easy/difficult, and comfortable/uncomfortable, they found taking the penile meatal swab was compared to collecting the FCU and their overall sample preference.

Consequently each participant will have two different samples taken:

Meatal swab: Aptima Combo 2 assay; Aptima MGen assay (if symptoms of urethritis)

First-catch urine sample: Aptima Combo 2 assay; Aptima MGen assay (if symptoms of urethritis)

The self-taken penile meatal and the FCU samples will be tested for C. trachomatis and N. gonorrhoeae using the Hologic Aptima Combo 2 assay (AC2), and those from participants with symptoms of urethritis will be tested for M. genitalium using Aptima MGen assay, according to the manufacturer's instructions (Hologic, San Diego, CA, USA). Positive tests for C. trachomatis will be retested using the Aptima CT assay and positive tests for N. gonorrhoeae will be retested using the Aptima GC assay, both of which use a different target to the AC2. A test will only be categorised as clinically positive if the appropriate confirmatory test is also positive. Positive tests for M. genitalium will be tested for M. genitalium macrolide and fluoroquinolone-resistance mutations by in-house PCR using Sanger sequencing to characterise mutants in the 23s gene for macrolide resistance and gyrA and parC genes for fluoroquinolone resistance (as developed by the Sexually Transmitted Bacteria Reference Unit, Public Health England). The resistance test will also act as the confirmatory test if the amplification is successful. It is anticipated that amplification will not be successful in up to 20% of the positive Aptima Mgen assays, because of the better sensitity of the commercial assay, in which case these positive samples for M. genitalium will be frozen, batched and shipped to Hologic, San Diego, CA, for confirmatory testing. The participant will be managed as if M. genitalium positive whilst waiting for these confirmatory results in view of the high specificity of the Aptima MGen assay, and to avoid further morbidity and sexual transmission.