• Genitourinary Medicine Services
• Chlamydia Infection
• Gonorrhoea

Rapid on-site diagnostics permit prompt recognition and treatment of infections. We introduced the GeneXpert system (Cepheid, California, USA) within 56 Dean Street, a central London sexual health clinic. The machine processes Chlamydia trachomatis (CT) and Neisseria gonorrhoeae (NG) samples in 90 min by real-time PCR.

We present the results of the service evaluation of a pilot where GeneXpert was used to process samples from individuals attending outreach or specialised clinics. Asymptomatic attenders whose samples were processed using the GeneXpert system were compared with asymptomatic ‘standard of care’ users attending 56 Dean Street whose samples were analysed offsite in the hospital laboratory. All patients with a positive GeneXpert NG and/or CT result were matched with a control with the same infection diagnosed and date of attendance. The same criteria were used to match the first 50 asymptomatic attenders with negative GeneXpert results with 50 ‘standard of care’ patients with negative results. We retrospectively obtained information from the clinic notes, including demographics, site of infection, date attender informed of diagnosis and date treated. Ethical approval was not sought as this was a service evaluation.

From 19 April 2013 to 7 January 2014, 196 asymptomatic individuals underwent GeneXpert sample processing. Of these, 28 (14%) had positive results (4 CT, 20 NG, 4 both CT/NG). The majority (26/28; 93%) were MSM of median age 34 years (IQR 28–39 years). For patients with positive results, the median time from testing to treatment was 2 days (IQR 1–6 days) for GeneXpert and 10 days (IQR 7–11 days) for the matched group. Median time from testing to informing attender was 1 day (IQR 1–3 days) vs 8 days (IQR 7–9 days) (GeneXpert vs matched) and from informing to treatment was 1 day (IQR 0–2 days) vs 1 day (IQR 1–4 days), respectively. For 50 attenders with negative results, the median time to informing of negative results was 1 day (IQR 1–2 days) for GeneXpert and 12 days (IQR 8–14 days) for the matched group.

The introduction of on-site diagnostics using GeneXpert reduced the time from testing to treatment compared with standard of care for asymptomatic clinic attenders. This is due to informing attenders of their results more rapidly. There was no change in the time to treatment following notification of their infection. On-site diagnostics also reduced the time to receiving negative results. The introduction of GeneXpert within sexual health services has the potential to reduce the prevalence of CT and NG in the community by reducing the duration of infectivity.