CROI 2025 Abstract eBook

Abstract eBook

Oral Abstracts

161

Higher Odds of Congenital Syphilis With 9- vs 7-Day Prenatal Treatment Intervals for Late Syphilis Kelly A. Johnson 1 , Eric Tang 2 , Robert E. Snyder 2 , Rosalyn Plotzker 1 , Kathleen Jacobson 2 , Nicole Burghardt 2 1 University of California San Francisco, San Francisco, CA, USA, 2 California Department of Public Health, Richmond, CA, USA Background: Congenital syphilis (CS) is an urgent threat; cases are at their highest rate (102.5/100,000 live births) since 1991. The only treatment (tx) for late latent syphilis (LLS) in pregnancy is 3 doses of benzathine penicillin G (BPGx3), given at 7-day (d) intervals. If intervals exceed 9d, US guidelines recommend restarting the full tx series, implying intervals up to 9d are acceptable. We previously demonstrated CS is not more likely with prenatal BPGx3 at 6-8d vs strict 7d intervals (OR 1.0, 95%CI 0.4-3.0), but there are no studies of 9d. Methods: Using California surveillance data, we leveraged an existing cohort of all mother/infant dyads wherein the parent had LLS in pregnancy from 1/1/16 6/30/19. Since only 5 dyads in this cohort received BPGx3 with a 9d interval, we enriched the study population with additional dyads who received BPGx3 with at least one 9d interval (and no intervals outside 6-9d), from a later period (7/1/19-12/31/23). We divided all dyads into 3 groups: adequate tx (Atx: BPGx3 at strict 7 or 6-8d intervals, started 30+d before delivery); BPGx3 at 6-9d (at least one 9d interval, no intervals outside 6-9d, started 30+d before delivery), and no/inadequate tx (NAtx). We compared clinical/demographic characteristics and infant CS incidence proportions via chi-squared/Wilcoxon rank sum, then estimated odds of CS by group via logistic regression. Results: We analyzed 1109 dyads: 677 Atx, 22 BPGx3 at 6-9d, and 410 NAtx. Comparing Atx vs 6-9d dyads, there were no differences (p>0.05) in maternal HIV (0.5 vs 0% positive), maternal RPRs 1:32+ (45.1 vs 40.9%), prenatal care (97.3 vs 95.5% received care), or gestational age at syphilis tx (median 16 vs 21 weeks). CS incidence proportions were 5.6% (38/677) for Atx, 18.2% (4/22) for 6-9d, and 36.8% (151/410) for NAtx (p=0.01 for 6-9d vs Atx). With Atx as reference, odds of CS were 3.7 (95%CI 1.2-11.6) for 6-9d and 9.8 (95%CI 6.7-14.4) for NAtx (Table 1). Conclusions: Compared to Atx, odds of CS approached 4-fold higher among dyads who received BPGx3 with 9d interval(s). These findings question current guidelines, suggesting CS may be more likely when BPG intervals are extended to 9d. Limitations include small numbers (preventing controlling for confounders) and the fact that most 6-9d dyads were from a later period than the comparator dyads. Still, given lack of data otherwise and while awaiting larger studies with higher statistical power, clinicians should consider erring on the side of caution, avoiding intervals outside 6-8d. DoxyPEP Eligibility, Use, and Potential for STI Reduction in a Large HIV Cohort in Washington, DC Yun Seong Ji 1 , Shannon K. Barth 1 , Amanda D. Castel 1 , Morgan Byrne 2 , Temi Oke 3 , Adedotun Ogunbajo 3 , Michael Horberg 4 , Anne Monroe 1 , for the DC Cohort Executive Committee 1 The George Washington University, Washington, DC, USA, 2 George Washington University, Washington, DC, USA, 3 Us Helping Us, People Into Living, Inc, Washington, DC, USA, 4 Kaiser Permanente Mid-Atlantic States, Rockville, MD, USA Background: Doxycycline post-exposure prophylaxis (DoxyPEP) use can significantly reduce the incidence of bacterial sexually transmitted infections (STIs), yet uptake has been low among people with HIV (PWH). In Washington, DC, high rates of STIs have been observed among PWH. We assessed STI diagnosis rates, DoxyPEP eligibility, use, and the potential impact of DoxyPEP prescribing on STI incidence among a large cohort of PWH in Washington, DC. Methods: DC Cohort longitudinal HIV cohort participants were considered DoxyPEP eligible per the CDC guidelines if they were men who have sex with men (MSM) or transwomen (TW) diagnosed with gonorrhea, chlamydia, and/or syphilis in a calendar year during the observation period (1/1/2019-12/31/2023). We assessed the number of DoxyPEP eligible PWH and DoxyPEP prescriptions. We conducted descriptive statistics on demographics, sexual behaviors, and HIV viral loads (VL). We calculated STI diagnosis rates and estimated the potential impact of DoxyPEP prescribing by assessing the proportion of diagnoses potentially averted based on efficacy trial results. Using the number needed to treat (NNT) with DoxyPEP for one year to avert one STI diagnosis, we estimated the efficiency of three prescribing strategies for PWH with 1) any STI, 2) a concurrent STI, or 3) ≥2 STIs in the past 12 months.

younger age, no associations were found in multivariable modeling (Table 1). Similarly, there were no factors significantly associated with clearance of mpox DNA at day 8. Clearance of mpox DNA at Day 8 was not associated with faster clinical resolution. Conclusions: This interim exploratory analysis of participants receiving open-label tecovirimat did not identify predictors of clinical mpox resolution. Compared to PALM007 participants with Clade 1 mpox, we found lower lesion counts and slower clinical resolution. Further investigation is needed. Missed Opportunities for Syphilis Diagnosis With Targeted Compared to Universal Screening Kimberly A. Stanford 1 , Joseph Mason 1 , Eleanor Friedman 1 , Aniruddha Hazra 1 , John Schneider 2 1 University of Chicago Medical Center, Chicago, IL, USA, 2 University of Chicago, Chicago, IL, USA Background: As syphilis rates rise, emergency department (ED) screening has been proposed as an important opportunity for early diagnosis and treatment of syphilis, especially for communities with limited access to care, for whom the ED visit may represent their primary contact with the healthcare system. Given potential increased costs and resources needed for universal screening, models targeted to certain high priority groups have been proposed. However, it is unknown if these targeted screening models successfully detect the majority of syphilis cases. Methods: In May 2019, a routine, opt-out, syphilis screening program for all ED patients under age 65 was implemented at a large, urban, tertiary care hospital in Chicago. This study retrospectively reviewed all ED encounters that included syphilis screening for the two-year period after implementation of the screening program. Syphilis cases were defined by a combination of positive serology, rapid plasma regain (RPR) titers, and clinical history derived from chart review. Descriptive statistics were used to evaluate the hypothetical sensitivity of screening models targeted to 1) only persons tested for gonorrhea or chlamydia, 2) women of reproductive age, 3) anyone receiving a blood draw, or 4) anyone receiving a complete blood count (CBC), compared to the cases detected with universal screening. Results: A total of 37,289 individuals were screened for syphilis during the two-year study period, of whom 624 (1.7%) were considered active syphilis cases. Had syphilis screening been performed only in patients receiving testing for gonorrhea or chlamydia, only 147 cases would have been identified (23.6% sensitivity). Screening only women of reproductive age would have identified 142 cases (22.8% sensitivity). Notably, screening only patients undergoing an unrelated blood draw would have identified 516 cases (82.7% sensitivity), and screening only those receiving a CBC would have identified 472 cases (75.6% sensitivity). Conclusions: This study found that targeted models of syphilis screening would miss a large proportion of syphilis cases. While implementation of universal ED screening may require additional resources and infrastructure, it may be the most effective strategy to address the syphilis epidemic in high prevalence communities facing major health care disparities.

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CROI 2025