GonoScreen: Efficacy of Screening STIs in MSM

This study is a multicentre, controlled, randomized trial of 3x3 Ng/Ct screening (comparator) vs. no screening (intervention). It will be performed in the PrEP cohorts situated at the Institute of Tropical Medicine (ITM), Hôpital Saint-Pierre (HSP), Liège University Hospital (CHU), University Hospital of Gent (UZG) and Erasmus Hospital (EH). All men in follow up at these five centres who report having had sex with another man in the previous year and are enrolled for PrEP follow up will be eligible to participate in the study. After signing informed consent participants will be randomized via a computer-generated schema to either 3x3 screening or no Ng/Ct screening. In both arms, participants will be followed up in an identical fashion including 3x3 screening. The only difference between the arms will be that in the screening arm, Ng/Ct results will be sent by the STI Laboratory to the study physicians and these participants will be treated and partner contact tracing will be done. The Sexually Transmitted Infection (STI) Laboratory will only process the samples/report the results from the non-screening arm at the end of the study. In both arms, all individuals with symptoms compatible with Ng or Ct will be tested and treated for these infections according to current best practice guidelines. At the end of the 12-month study period, participants whose most recent tests were positive for Ng or Ct will receive treatment for these.

• No Screening (Other): the STI Laboratory will only process the samples/report the results from the non-screening arm at the end of the study.

Primary outcomes

• Incidence Rate of Ng Plus Ct Detected at Any Site Whilst Individuals Are Screened vs. Not Screened [12 months]: number of diagnoses of Ng plus Ct in 12 months in screening/non-screening arms divided by number of scheduled study visits with available results for the diagnosis of Ng/Ct. The denominator does not include unscheduled visits.

Secondary outcomes

• Cumulative Antimicrobial Exposure (Ceftriaxone/Azithromycin/Doxycycline) [12 months]: Number of standard doses per 1000 person-years for azithromycin, ceftriaxone and doxycycline
• Incidence Rate of Symptomatic Ng Plus Ct [12 months]: Number of diagnoses of symptomatic Ng and Ct infections over 12 months divided by number of visits
• Incidence Rate of Syphilis [12 months]: Number of diagnoses of syphilis over 12 months divided by number of visits

Sex: Male, ages: 18 Years to any, accepts healthy volunteers

Inclusion Criteria:

* Able and willing to provide informed consent
* Men (born as males) and transwomen aged 18 or more
* Has had sex** with another man in the last 12 months
* Enrolled in Belgian PrEP program at ITM/HSP/EH/CHU/UZG with approval for TDF/FTC (Tenofovir disoproxil fumarate/Emtricitabine) reimbursement from a Belgian Medical Aid
* Willing to comply with the study procedures and to attend the clinic for the 3-monthly visits

Exclusion Criteria:

* Enrolment in another interventional trial
* Tests HIV-positive at screening
* Symptoms of proctitis or urethritis

Participant flow

Outcome results

• Incidence Rate of Ng Plus Ct Detected at Any Site Whilst Individuals Are Screened vs. Not Screened (Primary), Number, Ng or CT cases per study visit: Screening 0.155 (0.128 to 0.186); No Screening 0.205 (0.171 to 0.246)
• Cumulative Antimicrobial Exposure (Ceftriaxone/Azithromycin/Doxycycline) (Secondary), Number, doses per 1000 person-years: Screening 0.0059 (0.0055 to 0.0063); No Screening 0.0046 (0.0043 to 0.0050)
• Incidence Rate of Symptomatic Ng Plus Ct (Secondary), Number, Symptomatic infections per study visit: Screening 0.034 (0.023 to 0.049); No Screening 0.046 (0.032 to 0.067)
• Incidence Rate of Syphilis (Secondary), Number, Syphilis cases per study visit: Screening 0.018 (0.011 to 0.029); No Screening 0.026 (0.016 to 0.042)

Adverse events

Time frame: No adverse event data collected in this study.

• Results publication: Vanbaelen T, Tsoumanis A, Florence E, Van Dijck C, Huis In 't Veld D, Sauvage AS, Herssens N, De Baetselier I, Rotsaert A, Verhoeven V, Henrard S, Van Herrewege Y, Van den Bossche D, Goffard JC, Padalko E, Reyniers T, Vuylsteke B, Hayette MP, Libois A, Kenyon C. Effect of screening for Neisseria gonorrhoeae and Chlamydia trachomatis on incidence of these infections in men who have sex with men and transgender women taking HIV pre-exposure prophylaxis (the Gonoscreen study): results from a randomised, multicentre, controlled trial. Lancet HIV. 2024 Apr;11(4):e233-e244. doi: 10.1016/S2352-3018(23)00299-0. Epub 2024 Feb 26. PMID 38423024

• Study Protocol (PDF, 2021-04-28)
• Statistical Analysis Plan (PDF, 2021-06-01)

• Chris Kenyon, MD, Principal investigator, Institute of Tropical Medicine Antwerp