(P68) Gonorrhoea Undetected Resistance Laboratory Study (GURLS): a case-finding study for ceftriaxone-resistant Neisseria gonorrhoeae in England

Background: Since September 2021, 10 cases of ceftriaxone-resistant Neisseria gonorrhoeae (NG) were detected in England, compared with nine cases during the previous 6 years. Most of these were heterosexuals in their 20s who had travelled from the Asia-Pacific region to study. However, some of the recent cases acquired infection in England and not all partners could be traced. There is a need to quantify the prevalence of undetected ceftriaxone-resistant NG in England.

Methods: In England, 50% of NG diagnoses are based on a nucleic acid amplification test (NAAT) with no isolate available for phenotypic susceptibility testing. The national reference laboratory introduced a PCR assay to detect mutations in the penA gene associated with ceftriaxone resistance. A protocol was developed for the Gonorrhoea Undetected Resistance Laboratory Study (GURLS) to focus screening using the penA PCR. National STI surveillance data (2017-2021) provided information on NG diagnoses by sexual health clinic (SHC), gender, age, ethnicity and country of birth (China, Taiwan, Hong Kong, Thailand, Vietnam, Japan, Philippines). Higher Education Statistics Agency data was used to obtain student country of origin for English universities. Sample size calculations were performed.

Results: GURLS will select women (as a proxy for heterosexual behaviour) with NG attending SHCs in university towns with a high proportion of individuals of Asian-Pacific ethnicity or born in countries of the Asia-Pacific region. STI surveillance data identified 22 SHCs in England reporting >10 NG cases in women aged 18-30, of Asian-Pacific ethnicity or Asia-Pacific country of birth. There were 21 universities in England with >2000 students from the Asia-Pacific region in 2020-21. Combining these two datasets identified 14/22 SHCs located in these university towns. To detect a prevalence of ceftriaxone-resistant NG of 0.1% (95% CI 0.16-1.16%) a sample size of 1000 specimens is required.

All NG NAAT positive specimens from women aged 18-30 from these 14 SHCs will be sent to the national reference laboratory for penA PCR. Clinical and epidemiological data will be collected for positive cases.

Conclusion: GURLS will provide data to estimate the prevalence of ceftriaxone-resistant NG in England and will be used to inform national testing and management guidelines.