Integrating aetiologic testing for Chlamydia trachomatis and Neisseria gonorrhoeae using GeneXpert

Integrating Aetiologic Testing for Chlamydia trachomatis and Neisseria gonorrhoeae Using GeneXpert®: A Pilot Study

Study Rationale

Effective STI screening and treatment strategies can significantly reduce population-level incidence. Prioritizing GeneXpert®-based testing among youth aged 15-24 and individuals in HIV care offers the potential for substantial reductions in bacterial STI prevalence over a decade, even with limited coverage.

South Africa’s existing GeneXpert® infrastructure, deployed nationwide since 2011 for TB testing, provides a unique opportunity to integrate STI screening. The Xpert® CT/NG® test meets WHO REASSURED criteria, delivering results within 90 minutes via National Health Laboratory Service (NHLS) platforms, presenting an innovative solution for point-of-care (POC) testing.

Primary Objective

• To evaluate whether same-day testing and treatment significantly improve STI treatment completion rates compared to standard testing methods.

Secondary Objectives

• Assess CT/NG prevalence and factors associated with STI infection and treatment outcomes.
• Explore partner management preferences.
• Investigate the acceptability of STI screening among clients, healthcare providers, and laboratory staff, comparing testing approaches.
• Evaluate the user experience of vaginal swab self-collection instruction documents as part of a larger diagnostics evaluation protocol.

Investigators

• Principal Investigator: Prof Sinead Delany-Moretlwe
• Sub-Investigator: Dr Danielle Travill

Abstract

Same day testing and treatment for STIs in adolescents: results of a pilot randomised controlled trial in South Africa

Danielle Travill, Dorothy Machemedze, Phindi Zwane, Thembekile Mokhele, Lerato Makhale, Zinhle Sokhela, Mosidi Maraba, Sinead Delany-Moretlwe. HIVR4P 2024, Lima, Peru. 6 to 10 October 2024.

Background: Laboratory-based testing for STIs is not routine in South Africa, but studies suggest that clients would prefer point-of-care (POC) sexually transmitted infection (STI) testing, and that same day testing may lead to better treatment completion and reduce STI transmission. We conducted a pilot randomised trial to evaluate whether same day testing and treatment for positive tests (SD) improved treatment completion rates.

Methods: The study was conducted in an adolescent-friendly primary health care facility in Johannesburg from August 2023 to February 2024. Participants 18 years or older, sexually active in the past three months, at elevated risk for STIs, and able to provide a means of contact were included. Randomisation was by day 1:1 to either SD or standard laboratory testing with results return and treatment in 24-48 hours. Urine samples were tested for C.trachomatis (CT) and N.gonorrhoeae (NG) using GeneXpert™. The primary outcome of treatment completion within 30 days, was assessed by study arm using chi-squared tests. Time to treatment by study arm was assessed by log-rank test. Cox proportional hazards models assessed factors associated with time to treatment.

Results: Of 355 screened, 350 were enrolled, and 348 with valid tests were analysed. Median age was 21 years (IQR, 20-23), and 10% (33/348) had STI symptoms at that visit. Overall, 40% (138/348) had confirmed CT/NG; 79% (109/138) were asymptomatic. In the ITT analysis, 97% (65/67) in the SD group compared to 92% (65/71) in the standard group completed treatment within 30 days (risk ratio [RR] 1.06, 95% CI 0.98-1.15). In the per- protocol analysis, treatment completion rates were higher in the SD group (98% [63/67] SD vs 92% [49/71] standard; RR 1.36, 95% CI 1.15-1.61). Median time to treatment completion was significantly longer in the standard group (0 [SD] vs 3 [standard] days, p<0.0001). Being asymptomatic prolonged time to treatment (adjusted hazard ratio 2.38; 95% 1.48-3.85).

Conclusion: Curable STIs were high and frequently asymptomatic or unrecognised in this adolescent population. With adequate counselling and follow up, treatment completion rates are high but can be improved with same day testing and treatment.

Latest Update:

December 2024

For more about Integrating aetiologic testing for Chlamydia trachomatis and Neisseria gonorrhoeae using GeneXpert please email rhicomms@wrhi.ac.za