(P55) Implementing routine culturing and antimicrobial susceptibility testing for Neisseria gonorrhoeae within a HIV pre-exposure prophylaxis program in Hanoi, Vietnam

Background: Antimicrobial resistance (AMR) in Neisseria gonorrhoeae (NG) is an urgent global health issue. Patients on HIV pre-exposure prophylaxis (PrEP) have high rates of NG infections and routine testing is recommended. The objectives of this study were to implement routine testing and culturing of NG infections within a PrEP program in Vietnam in order to determine the prevalence of NG, NG culture-positivity, and to describe the patterns of AMR in NG.



Methods: From January through November 2022, participants in the PrEP program at the Sexual Health Promotion Clinic in Hanoi, Vietnam were enrolled. A survey collecting demographic, behavioral, and clinical characteristics was administered. Participants self-collected urine, rectal, and pharyngeal specimens for nucleic-acid amplification testing (NAAT). Those receiving same-day NG treatment also had swabs for NG culture collected. Participants NAAT-positive for NG were recalled for treatment and specimens were collected for culture and antibiotic susceptibility testing (AST).



Results: In total, 506 participants were enrolled. The median age was 24.9 years (IQR: 21.7– 29.6). All were male and reported having sex with men in the prior 12 months. The median number of sex partners in the prior month was 1 (IQR: 1 – 2). Symptoms within the prior week were reported by 41.7% (211/506). The overall prevalence of NG infections by NAAT was 14.8% (75/506); there were 16 (3.2%) urethral, 36 (7.1%) rectal, and 60 (11.9%) oropharyngeal NG infections. Among those with NG, 93.3% (70/75) returned for treatment and culturing, with a median of 7 days after initial collection. NG culture positivity was 35.7% (5/14) for urethral, 10.0% (3/30) for rectal, and 3.6% (2/56) for oropharyngeal. All NG isolates were susceptible to cefixime, ceftriaxone, and spectinomycin, while 40.0% (4/10) were non-susceptible to azithromycin.



Conclusions: A high prevalence of NG infections, was observed among MSM in a PrEP program in Hanoi, Vietnam. NG culture positivity was low, highlighting difficulties in culturing NG, particularly from extragenital sites. While many NG infections were asymptomatic, NAAT and culture positivity were higher among those reporting symptoms. AST of NG is important for AMR surveillance and optimization of NG culturing within PrEP program settings can enhance these efforts.