KCE-181133: Efficacy of screening STIs in MSM - the GonoScreen study

Summary (French or Dutch)

A study to assess if we should be screening men who have sex with men (MSM) for gonorrhoea and chlamydia if they do not have any symptoms.

The GonoScreen study aims to assess if there is any evidence that gonorrhoea/chlamydia screening works in MSM. It may be that screening is highly effective at reducing one’s risk of catching these infections. In this case the benefits of screening (less incidence or transmission of gonorrhoea and/or chlamydia) may still outweigh the risks (increased antibiotics consumptions, increased risk of resistance to antibiotics, health costs, impairment of natural immunity).

To assess this, the study will compare screening for chlamydia and gonorrhoea with not screening these infections in around 1000 MSM taking PrEP from 5 PrEP clinics in Belgium (Erasme Hospital, Institute of Tropical Medicine, Saint Pierre Hospital, UZ Gent and CHU Liege). Half the participants will be screened every three months and the other half will have the same samples taken every 3 months but these will only be analyzed at the end of the study. In all the study participants, testing for HIV, syphilis and hepatitis C will be performed as in routine care. All individuals who develop symptoms of a chlamydia or gonorrhoea infection during the study will be given conventional treatment

If the study finds that screening makes little difference to the incidence of gonorrhoea and chlamydia then there are strong arguments to stop or reduce the intensity of screening gonorrhoea and chlamydia in MSM.

Trial Description

Does screening for gonorrhea and chlamydia reduce the incidence of these infections in men who have sex with men taking HIV pre exposure prophylaxis (PrEP): a randomized, multicentre controlled trial

Participants (P)

PrEP cohorts situated at the Institute of Tropical Medicine (ITM), Hôpital Saint-Pierre (HSP), University Hospital of Gent (UZG), Erasmus Hospital (EH) and Liège University Hospital (CHU). 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.

Intervention (I)

Participants in the intervention arm will not be screened for Ng/Ct for a period of 12 months, in reference to the routine practice of screening (and treating screening-positive) participants every 3 months.

More specifically, participants in the intervention arm will have 3 site (urethra, pharynx and rectum) sampling performed every 3 months but these testing results will only be reported at the end of the 12 month period.

Control (C)

For a period of 12 months, all participants will be screened for Ng/Ct at three sites (urethra, pharynx and rectum) every three months according to current Belgian guidelines. If they test positive, they will be recalled for treatment for Ng/Ct and contact tracing.

Outcome (O)

Incidence rate of Ng plus Ct detected at any site whilst individuals are screened vs. not screened.

Trial Design

Multicentre, controlled, randomized trial of 3 site (urethra, pharynx and rectum) sampling performed every 3 months (3x3) for Neisseria gonorrhoea (Ng)/Chlamydia trachomatis (Ct) screening (comparator) vs. no screening (intervention)

Sample Size

1014 participants

Trial duration

26 months


€1 620 000




Trial team


Institute for Tropical Medicine

Chief Investigator

Chris Kenyon

Participating Investigators

Chris Kenyon, ITM, Antwerp

Sophie Henrard, Hôpital Erasme, Bxl

Agnes Libois , CHU St Pierre, Bxl

Diana Huis in ’t Veld, UZ Gent

Anne-Sophie Sauvage, CHU Liège






Clinicaltrials.gov: NCT04269434


Funding scheme

2018 Investigator led