CROI 2025 Abstract eBook

Abstract eBook

Poster Abstracts

1286 Effectiveness of Ceftriaxone Monotherapy for Gonorrhea Treatment Chiara Fusetti, Federica Salari, Francesco Petri, Alberto Rizzo, Andrea Giacomelli, Andrea Cavallo, Francesco Caruso, Loriana Morelli, Cristina Gervasoni, Davide Mileto, Maria Vittoria Cossu, Alessandra Lombardi, Agostino Riva, Andrea Gori, Davide Moschese Luigi Sacco University Hospital, Milan, Italy Background: Guidelines differ on first-line treatment of Gonorrhea (NGI). European and Australian guidelines recommend ceftriaxone (CRO) + azithromycin (AZM) to target resistant strains and minimize resistance emergence, while the CDC and UK favor CRO monotherapy due to increasing AZM resistance and concerns about cross-resistance in other pathogens. Follow-up also differ: the CDC advises a test-of-cure (TOC) only for pharyngeal infection, while others suggest it universally, especially when using alternative therapies. Although Italy is highly-burdened by antimicrobial resistance, our national and local ecology present a CRO decreased-susceptibility NG as low as 8%. In this context, the study compares the effectiveness of CRO 1g IM monotherapy versus combination in eradicating NGIs. Methods: All NGIs diagnosed at our clinic between January 2022 and August 2024, with a TOC performed at 28 days ±7, were retrospectively analyzed. Diagnoses were made using NAATs on pharyngeal, anal, vaginal swabs, and urine sample. Data collected included HIV status, PrEP use, symptoms of infection, antibiotic treatment, NAAT TOC results. Descriptive statistics were reported as counts and percentages, statistical analysis was performed using Pearson χ² or Fischer exact tests. Results: A total of 202 infections were identified: 41% anal, 40.5% pharyngeal, 18% urethral, and 0.5% vaginal. Of these, 61% involved PrEP-users, 27% PWH, and 12% people without HIV not in PrEP. 79% of infections (119/150) were asymptomatic, predominantly in pharyngeal (48%) and anal sites (47%). Urethral site were more likely to be symptomatic (n 16/31, 52%) than the others (p <0.001). CRO monotherapy was used in 54% of cases, while CRO+AZM in 39% of cases. Gentamicin±AZM was given in 5 cases due to allergy. Combination therapy was mainly found to be used in symptomatic cases (58% vs 19%; p <0.001), since treatment was usually given before microbiological results. TOC was negative in 99% of cases, with only 3 infections testing positive after CRO treatment. In the first case CRO was repeated resulting in a negative TOC. The second was a reinfection and in the last one a TOC was repeated one week later with a negative result. Conclusions: In a low-prevalence resistance setting CRO monotherapy is as effective as combination with AZM for treating NGIs, suggesting that CRO alone may be preferred to limit antibiotic use. For the same reason, the high treatment success rate may suggest that TOC may be unnecessary to reduce hospital visits and over-medication.

days of therapy (DOT) per 1000 person-days (1000-PD). The observed DOTs after DoxyPEP prescription were increased with %changes derived from regressions to obtain the expected DOTs in absence of DoxyPEP. Results: Overall, 754 MSM were prescribed DoxyPEP; during follow-up 222 (29.4%) reported using DoxyPEP. Median follow-up among DoxyPEP users were 15.8 months (IQR=12.1-19.2) and 10.8 (6.88-13.1) before and after prescription, respectively. Individuals' characteristics in Table. Among DoxyPEP users, 401 bSTIs (Tp 70, Ct 139, Ng 192) were detected before DoxyPEP prescription and 146 (Tp 26, Ct 32, Ng 88) after. Overall, DOT per 1000-PD was 1.26 for ceftriaxone, 0.37 for penicillin and 3.21 for doxycycline after DoxyPEP prescription; DoxyPEP DOT per 1000-PD was 7.00. Expected DOT per 1000-PD in the absence of DoxyPEP was 4.85 (95%CI=3.82-6.41) for ceftriaxone, 1.86 (95%CI=1.17-2.87) for penicillin, and 24.71 (95%CI=17.18-37.36) for doxycycline. Conclusions: A significant reduction in all considered antibiotics used for the treatment of bSTIs was achieved among DoxyPEP users.

1285 Antimicrobial Resistance of N. gonorrhoeae at a Community-Based Clinic, 2023-2024 Jun Tao 1 , Hannah Parent 1 , Walther Pfiefer 2 , Kristen Azevedo 3 , Sean Sierra Patev 3 , Glen Gallagher 3 , Thomas Bertrand 3 , Suzanne Bornschein 3 , Richard Huard 3 , Erick Costa 2 , Yelena Malyuta 4 , Max Erbe 4 , Alexi Almonte 1 , Amy Nunn 1 , Philip A. Chan 1 1 Brown University, Providence, RI, USA, 2 East Side Clinical Laboratory, East Providence, RI, USA, 3 Rhode Island Department of Health, Providence, RI, USA, 4 Open Door Health, Providence, RI, USA Background: Gonorrhea, caused by N. gonorrhoeae , has developed resistance to most antimicrobial treatments over time, including ciprofloxacin, tetracycline, penicillin, and cephalosporins. Importantly, baseline tetracycline resistance may impact the use of doxycycline as post-exposure prophylaxis (DoxyPEP) to prevent bacterial STIs. We evaluated baseline N. gonorrhoeae resistance in patients presenting to a community-based STI clinic. Methods: We reviewed demographic and behavioral data of patients presenting for HIV/STI testing at a community-based STI clinic in Providence, Rhode Island, between February 2023, and May 2024. N. gonorrhoeae was detected using nucleic acid amplification tests (NAAT). Bivariate and multivariate analyses were conducted to examine the factors that were associated with having at least one positive gonorrhea test. Results: A total of N=802 unique patients presented for HIV/STI testing. The median age was 31 years. The majority of patients were assigned male at birth (72%) and self-identified as non-heterosexual (75%). The majority of patients reported a prior history of STIs (52%), including chlamydia (45%), syphilis (20%), and gonorrhea (37%). Twelve out of 802 patients (1.5%) were HIV positive and 25% were actively using HIV PrEP. Additionally, 18% of patients reported the use of DoxyPEP. Sixteen percent (N=127) had at least one positive gonorrhea test during the study period. No statistically significant differences were observed across different racial and ethnic groups. People taking HIV PrEP were significantly more likely to test positive for gonorrhea (aOR: 3.00, 95% CI: 2.53 6.34) compared to those not on PrEP. Having a history of STIs, a moderate or high number of sexual partners, and engaging in sex with anonymous partners were all associated with significantly elevated odds of testing positive for gonorrhea. Among the 127 patients with at least one positive gonorrhea test, 116 had swab samples available for culture testing. Of these, 30 patients had positive culture results. All N. gonorrhoeae isolates were sensitive to Ceftriaxone, but only 10% were pan-sensitive. Sixty-percent (N=18) demonstrated some resistance to ciprofloxacin, 33% (N=10) to tetracyclines, and 0.03% (N=1) to cefixime. Conclusions: Antimicrobial resistance to N. gonorrhoeae is common and may limit effectiveness of HIV/STI prevention approaches such as DoxyPEP. New approaches to address antimicrobial resistance among N. gonorrhoeae and continued surveillance are needed.

Poster Abstracts

CROI 2025 426