Doxycycline Prophylaxis to Prevent Sexually Transmitted Infections in Women.

BACKGROUND: Doxycycline postexposure prophylaxis (PEP) has been shown to prevent sexually transmitted infections (STIs) among cisgender men and transgender women, but data from trials involving cisgender women are lacking. METHODS: We conducted a randomized, open-label trial comparing doxycycline PEP (doxycycline hyclate, 200 mg taken within 72 hours after condomless sex) with standard care among Kenyan women 18 to 30 years of age who were receiving preexposure prophylaxis against human immunodeficiency virus (HIV). The primary end point was any incident infection with Chlamydia trachomatis, Neisseria gonorrhoeae, or Treponema pallidum. Hair samples were collected quarterly for objective assessment of doxycycline use. RESULTS: A total of 449 participants underwent randomization; 224 were assigned to the doxycycline-PEP group and 225 to the standard-care group. Participants were followed quarterly over 12 months. A total of 109 incident STIs occurred (50 in the doxycycline-PEP group [25.1 per 100 person-years] and 59 in the standard-care group [29.0 per 100 person-years]), with no significant between-group difference in incidence (relative risk, 0.88; 95% confidence interval [CI], 0.60 to 1.29; P = 0.51). Among the 109 incident STIs, chlamydia accounted for 85 (78.0%) (35 in the doxycycline-PEP group and 50 in the standard-care group; relative risk, 0.73; 95% CI, 0.47 to 1.13). No serious adverse events were considered by the trial investigators to be related to doxycycline, and there were no incident HIV infections. Among 50 randomly selected participants in the doxycycline-PEP group, doxycycline was detected in 58 of 200 hair samples (29.0%). All N. gonorrhoeae-positive isolates were resistant to doxycycline. CONCLUSIONS: Among cisgender women, the incidence of STIs was not significantly lower with doxycycline PEP than with standard care. According to hair-sample analysis, the use of doxycycline PEP among those assigned to receive it was low. (Funded by the National Institutes of Health; dPEP ClinicalTrials.gov number, NCT04050540.).

Postexposure Doxycycline to Prevent Bacterial Sexually Transmitted Infections.

BACKGROUND: Interventions to reduce sexually transmitted infections (STIs) among men who have sex with men (MSM) are needed. METHODS: We conducted an open-label, randomized study involving MSM and transgender women who were taking preexposure prophylaxis (PrEP) against human immunodeficiency virus (HIV) infection (PrEP cohort) or living with HIV infection (persons living with HIV infection [PLWH] cohort) and who had had Neisseria gonorrhoeae (gonorrhea), Chlamydia trachomatis (chlamydia), or syphilis in the past year. Participants were randomly assigned in a 2:1 ratio to take 200 mg of doxycycline within 72 hours after condomless sex (doxycycline postexposure prophylaxis) or receive standard care without doxycycline. STI testing was performed quarterly. The primary end point was the incidence of at least one STI per follow-up quarter. RESULTS: Of 501 participants (327 in the PrEP cohort and 174 in the PLWH cohort), 67% were White, 7% Black, 11% Asian or Pacific Islander, and 30% Hispanic or Latino. In the PrEP cohort, an STI was diagnosed in 61 of 570 quarterly visits (10.7%) in the doxycycline group and 82 of 257 quarterly visits (31.9%) in the standard-care group, for an absolute difference of -21.2 percentage points and a relative risk of 0.34 (95% confidence interval [CI], 0.24 to 0.46; P<0.001). In the PLWH cohort, an STI was diagnosed in 36 of 305 quarterly visits (11.8%) in the doxycycline group and 39 of 128 quarterly visits (30.5%) in the standard-care group, for an absolute difference of -18.7 percentage points and a relative risk of 0.38 (95% CI, 0.24 to 0.60; P<0.001). The incidences of the three evaluated STIs were lower with doxycycline than with standard care; in the PrEP cohort, the relative risks were 0.45 (95% CI, 0.32 to 0.65) for gonorrhea, 0.12 (95% CI, 0.05 to 0.25) for chlamydia, and 0.13 (95% CI, 0.03 to 0.59) for syphilis, and in the PLWH cohort, the relative risks were 0.43 (95% CI, 0.26 to 0.71), 0.26 (95% CI, 0.12 to 0.57), and 0.23 (95% CI, 0.04 to 1.29), respectively. Five grade 3 adverse events and no serious adverse events were attributed to doxycycline. Of the participants with gonorrhea culture available, tetracycline-resistant gonorrhea occurred in 5 of 13 in the doxycycline groups and 2 of 16 in the standard-care groups. CONCLUSIONS: The combined incidence of gonorrhea, chlamydia, and syphilis was lower by two thirds with doxycycline postexposure prophylaxis than with standard care, a finding that supports its use among MSM with recent bacterial STIs. (Funded by the National Institutes of Health; DoxyPEP ClinicalTrials.gov number, NCT03980223.).

Genomic Epidemiology of Treponema pallidum and Circulation of Strains With Diminished tprK Antigen Variation Capability in Seattle, 2021-2022.

BACKGROUND: The incidence of syphilis continues to increase in the United States, yet little is known about Treponema pallidum genomic epidemiology within American metropolitan areas. METHODS: We performed whole-genome sequencing and tprK deep sequencing of 28 T. pallidum-containing specimens, collected mostly from remnant Aptima swab specimens from 24 individuals from Seattle Sexual Health Clinic during 2021-2022. RESULTS: All 12 individuals infected with Nichols-lineage strains were men who have sex with men, while a specific SS14 cluster (mean, 0.33 single-nucleotide variant) included 1 man who has sex with women and 5 women. All T. pallidum strains sequenced were azithromycin resistant via 23S ribosomal RNA A2058G mutation. Identical T. pallidum genomic sequences were found in pharyngeal and rectal swab specimens taken concurrently from the same individuals. The tprK sequences were less variable between patient-matched specimens and between epidemiologically linked clusters. We detected a 528-base pair deletion in the tprK donor site locus, eliminating 9 donor sites, in T. pallidum genomes of 3 individuals with secondary syphilis, associated with diminution of TprK diversity. CONCLUSIONS: We developed an end-to-end workflow for public health genomic surveillance of T. pallidum from remnant Aptima swab specimens. tprK sequencing may assist in linking cases beyond routine T. pallidum genome sequencing. T. pallidum strains with deletions in tprK donor sites currently circulate and are associated with diminished TprK antigenic diversity.

Phenotypic and molecular characterization of ß-lactamase-producing Klebsiella species among children discharged from hospital in Western Kenya.

BACKGROUND: The emergence and spread of ß-lactamase-producing Klebsiella spp. has been associated with a substantial healthcare burden resulting in therapeutic failures. We sought to describe the proportion of phenotypic resistance to commonly used antibiotics, characterize ß-lactamase genes among isolates with antimicrobial resistance (AMR), and assess the correlates of phenotypic AMR in Klebsiella spp. isolated from stool or rectal swab samples collected from children being discharged from hospital. METHODS: We conducted a cross-sectional study involving 245 children aged 1-59 months who were being discharged from hospitals in western Kenya between June 2016 and November 2019. Whole stool or rectal swab samples were collected and Klebsiella spp. isolated by standard microbiological culture. ß-lactamase genes were detected by PCR whilst phenotypic antimicrobial susceptibility was determined using the disc diffusion technique following standard microbiology protocols. Descriptive analyses were used to characterize phenotypic AMR and carriage of ß-lactamase-producing genes. The modified Poisson regression models were used to assess correlates of phenotypic beta-lactam resistance. RESULTS: The prevalence of ß-lactamase carriage among Klebsiella spp. isolates at hospital discharge was 62.9% (154/245). Antibiotic use during hospitalization (adjusted prevalence ratio [aPR] = 4.51; 95%CI: 1.79-11.4, p < 0.001), longer duration of hospitalization (aPR = 1.42; 95%CI: 1.14-1.77, p < 0.002), and access to treated water (aPR = 1.38; 95%CI: 1.12-1.71, p < 0.003), were significant predictors of phenotypically determined ß-lactamase. All the 154 ß-lactamase-producing Klebsiella spp. isolates had at least one genetic marker of ß-lactam/third-generation cephalosporin resistance. The most prevalent genes were blaCTX-M 142/154 (92.2%,) and blaSHV 142/154 (92.2%,) followed by blaTEM 88/154 (57.1%,) and blaOXA 48/154 (31.2%,) respectively. CONCLUSION: Carriage of ß-lactamase producing Klebsiella spp. in stool is common among children discharged from hospital in western Kenya and is associated with longer duration of hospitalization, antibiotic use, and access to treated water. The findings emphasize the need for continued monitoring of antimicrobial susceptibility patterns to inform the development and implementation of appropriate treatment guidelines. In addition, we recommend measures beyond antimicrobial stewardship and infection control within hospitals, improved sanitation, and access to safe drinking water to mitigate the spread of ß-lactamase-producing Klebsiella pathogens in these and similar settings.

Oral sexual exposures can lead to viable rectal Chlamydia trachomatis infection.

BACKGROUND: Chlamydia trachomatis (CT) acquired orally may survive passage through the gastrointestinal tract and establish an infection in the rectum, but how often this occurs is unknown. METHODS: In 2019-2022 we enrolled individuals assigned male at birth who reported sex with men and denied receptive anal sex in the past 2 years. Participants enrolled at the Seattle Sexual Health Clinic or online. Participants completed a behavioral survey and self-collected rectal swabs for CT nucleic acid amplification testing (NAAT) and culture and viability PCR (vPCR). We defined oral exposures as fellatio, cunnilingus, and oral-anal (i.e., rimming). RESULTS: We enrolled 275 men; 60 (22%) reported only oral exposures in the past 12 months. Of these, five (8.3%) tested positive for rectal CT by NAAT; 1 (2%) had viable CT detected (culture-positive; vPCR-positive). Another 43 participants reported only oral exposures in the past 2 months but rectal exposures 3-12 months ago. Of these, 4 (9%) tested NAAT-positive for rectal CT; 1 had viable CT detected (culture-negative; vPCR-positive). CONCLUSIONS: Passage of CT from the mouth to the rectum occurs, but is most often nucleic acid remnants rather than viable bacteria. Nonetheless, it appears possible to establish a viable rectal CT infection via oral exposures.

Asymptomatic and Subclinical Mpox: An Association With Modified Vaccinia Ankara Vaccine.

BACKGROUND: How often mpox causes asymptomatic infections, particularly among persons who have received the Modified Vaccinia Ankara (MVA) vaccine, is unknown. METHODS: We performed mpox polymerase chain reaction testing on rectal and pharyngeal specimens collected from symptomatic and asymptomatic patients at a sexual health clinic in Seattle, WA, between May 2022 and May 2023. Analyses evaluated the prevalence of asymptomatic or subclinical infection and, among persons with polymerase chain reaction-positive tests, the association of MVA vaccination status with the symptomatic infection. RESULTS: The study population included 1663 persons tested for mpox during 2353 clinic visits. Ninety-three percent of study participants were cisgender men and 96% were men who have sex with men. A total of 198 symptomatic patients (30%) had a first mpox-positive test during 664 visits. Eighteen patients (1.1%) tested during 1689 visits had asymptomatic or subclinical mpox based on a positive rectal or pharyngeal test done in the absence of testing done because of clinical suspicion for mpox. Fourteen (78%) of 18 persons with asymptomatic/subclinical mpox and 53 (26%) of 198 persons with symptomatic mpox had received at least 1 dose of the MVA vaccine ( P < 0.0001). Controlling for calendar month, study subjects who received 1 and 2 doses of MVA vaccine were 4.4 (95% confidence interval, 1.3-15) and 11.9 (3.6-40) times more likely to have asymptomatic versus symptomatic mpox, respectively, than persons who were unvaccinated. CONCLUSIONS: Asymptomatic mpox is uncommon. Modified Vaccinia Ankara vaccination is associated with an asymptomatic/subclinical infection among persons with mpox.

Whole-Genome Sequencing to Predict Antimicrobial Susceptibility Profiles in Neisseria gonorrhoeae.

BACKGROUND: Neisseria gonorrhoeae is a major public health problem due to increasing incidence and antimicrobial resistance. Genetic markers of reduced susceptibility have been identified; the extent to which those are representative of global antimicrobial resistance is unknown. We evaluated the performance of whole-genome sequencing (WGS) used to predict susceptibility to ciprofloxacin and other antimicrobials using a global collection of N. gonorrhoeae isolates. METHODS: Susceptibility testing of common antimicrobials and the recently developed zolifodacin was performed using agar dilution to determine minimum inhibitory concentrations (MICs). We identified resistance alleles at loci known to contribute to antimicrobial resistance in N. gonorrhoeae from WGS data. We tested the ability of each locus to predict antimicrobial susceptibility. RESULTS: A total of 481 N. gonorrhoeae isolates, collected between 2004 and 2019 and making up 457 unique genomes, were sourced from 5 countries. All isolates with demonstrated susceptibility to ciprofloxacin (MIC ≤0.06 µg/mL) had a wild-type gyrA codon 91. Multilocus approaches were needed to predict susceptibility to other antimicrobials. All isolates were susceptible to zoliflodacin, defined by an MIC ≤0.25 µg/mL. CONCLUSIONS: Single marker prediction can be used to inform ciprofloxacin treatment of N. gonorrhoeae infection. A combination of molecular markers may be needed to determine susceptibility for other antimicrobials.

Mycoplasma genitalium in the US (MyGeniUS): Surveillance Data From Sexual Health Clinics in 4 US Regions.

BACKGROUND: Mycoplasma genitalium (MG) is on the CDC Watch List of Antimicrobial Resistance Threats, yet there is no systematic surveillance to monitor change. METHODS: We initiated surveillance in sexual health clinics in 6 cities, selecting a quota sample of urogenital specimens tested for gonorrhea and/or chlamydia. We abstracted patient data from medical records and detected MG and macrolide-resistance mutations (MRMs) by nucleic acid amplification testing. We used Poisson regression to estimate adjusted prevalence ratios (aPRs) and 95% CIs, adjusting for sampling criteria (site, birth sex, symptom status). RESULTS: From October-December 2020 we tested 1743 urogenital specimens: 57.0% from males, 46.1% from non-Hispanic Black persons, and 43.8% from symptomatic patients. MG prevalence was 16.6% (95% CI: 14.9-18.5%; site-specific range: 9.9-23.5%) and higher in St Louis (aPR: 1.9; 1.27-2.85), Greensboro (aPR: 1.8; 1.18-2.79), and Denver (aPR: 1.7; 1.12-2.44) than Seattle. Prevalence was highest in persons <18 years (30.4%) and declined 3% per each additional year of age (aPR: .97; .955-.982). MG was detected in 26.8%, 21.1%, 11.8%, and 15.4% of urethritis, vaginitis, cervicitis, and pelvic inflammatory disease (PID), respectively. It was present in 9% of asymptomatic males and 15.4% of asymptomatic females, and associated with male urethritis (aPR: 1.7; 1.22-2.50) and chlamydia (aPR: 1.7; 1.13-2.53). MRM prevalence was 59.1% (95% CI: 53.1-64.8%; site-specific range: 51.3-70.6%). MRMs were associated with vaginitis (aPR: 1.8; 1.14-2.85), cervicitis (aPR: 3.5; 1.69-7.30), and PID cervicitis (aPR: 1.8; 1.09-3.08). CONCLUSIONS: MG infection is common in persons at high risk of sexually transmitted infections; testing symptomatic patients would facilitate appropriate therapy. Macrolide resistance is high and azithromycin should not be used without resistance testing.

Prior Exposure to Azithromycin and Azithromycin Resistance Among Persons Diagnosed With Neisseria gonorrhoeae Infection at a Sexual Health Clinic: 2012-2019.

BACKGROUND: There is conflicting evidence on whether prior azithromycin (AZM) exposure is associated with reduced susceptibility to AZM (AZMRS) among persons infected with Neisseria gonorrhoeae (NG). METHODS: The study population included Public Health-Seattle and King County Sexual Health Clinic (SHC) patients with culture-positive NG infection at ≥1 anatomic site whose isolates were tested for AZM susceptibility in 2012-2019. We used multivariate logistic regression to examine the association of time since last AZM prescription from the SHC in ≤12 months with subsequent diagnosis with AZMRS NG (minimum inhibitory concentration [MIC], ≥2.0 µg/mL) and used linear regression to assess the association between the number of AZM prescriptions in ≤12 months and AZM MIC level, controlling for demographic, behavioral, and clinical characteristics. RESULTS: A total of 2155 unique patients had 2828 incident NG infections, 156 (6%) of which were caused by AZMRS NG. AZMRS NG was strongly associated with receipt of AZM from the SHC in the prior 29 days (adjusted odds ratio, 6.76; 95% confidence interval [CI], 1.76 to 25.90) but not with receipt of AZM in the prior 30-365 days. Log AZM MIC level was not associated with the number of AZM prescriptions within ≤12 months (adjusted correlation, 0.0004; 95% CI, -.04 to .037) but was associated with number of prescriptions within <30 days (adjusted coefficient, 0.56; 95% CI, .13 to .98). CONCLUSIONS: Recent individual-level AZM treatment is associated with subsequent AZMRS gonococcal infections. The long half-life and persistence of subtherapeutic levels of AZM may result in selection of resistant NG strains in persons with recent AZM use.

Plasmid-mediated quinolone resistance genes detected in Ciprofloxacin non-susceptible Escherichia coli and Klebsiella isolated from children under five years at hospital discharge, Kenya.

BACKGROUND: The increasing spread of fluoroquinolone resistant enteric bacteria is a global public health concern. Children recently discharged from the hospital are at high risk of carriage of antimicrobial resistance (AMR) due to frequent exposure to antimicrobials during inpatient stays. This study aimed to determine the prevalence, correlates of ciprofloxacin (CIP) non-susceptibility, and distribution of plasmid-mediated quinolone resistance (PMQR) genes in Escherichia coli (E. coli) and Klebsiella spp isolated from children under five years being discharged from two Kenyan Hospitals. METHODS: E. coli and Klebsiella spp were isolated from fecal samples from children discharged from hospital and subjected to antimicrobial susceptibility testing (AST) by disc diffusion and E-test. CIP non-susceptible isolates were screened for seven PMQR genes using multiplex polymerase chain reaction (PCR). Poisson regression was used to determine the association between the carriage of CIP non-susceptible isolates and patient characteristics. RESULTS: Of the 280 CIP non-susceptible isolates: 188 E. coli and 92 Klebsiella spp isolates identified among 266 discharged children, 195 (68%) were CIP-non-susceptible with minimum inhibitory concentrations (MICs) of ≥ 1 µg/mL. Among these 195 isolates, 130 (67%) had high-level CIP MIC = ≥ 32 µg/mL). Over 80% of the isolates had at least one PMQR gene identified: aac(6')lb-cr (60%), qnrB (24%), oqxAB (22%), qnrS (16%), and qepA (6%), however, qnrA was not identified in any isolates tested. Co-carriage of qnrB with acc(6')-lb-cr was the most predominant accounting for 20% of all the isolates. Ceftriaxone use during hospital admission and the presence of extended spectrum beta-lactamase (ESBL) production were significantly associated with the carriage of CIP non-susceptible E. coli and Klebsiella spp. CONCLUSION: CIP non-susceptibility is common among E. coli and Klebsiella spp isolated from hospital discharged children in Kenya. Carriage and co-carriage of PMQR, including the newly identified qepA gene, were frequently observed. These findings suggest that children leaving the hospital may serve as an important reservoir for transmission of resistant E. coli and Klebsiella spp to the community. Enhanced surveillance for AMR determinants is critical to inform interventions to control antimicrobial-resistant bacteria.

Pharyngeal Gonorrhea in Heterosexual Male and Female Sex Partners of Persons With Gonorrhea.

BACKGROUND: Current guidance from the US Centers for Disease Control and Prevention recommends empiric treatment for persons exposed to sexually transmitted infections, including Neisseria gonorrhoeae ( NG ). As an antimicrobial stewardship measure, some clinics now recommend a test and treat strategy, but reliance on urogenital testing only may miss cases. METHODS: We conducted a descriptive analysis of pharyngeal NG infection in men who have sex with women (MSW) and women seeking care at a sexual health clinic in Seattle, WA, from February 2017 to July 2021 because of sexual contact to a partner diagnosed with gonorrhea. We also explored behavioral factors associated with pharyngeal NG positivity (by culture or nucleic acid amplification test by χ2 analysis. RESULTS: Among 352 NG contacts tested for urogenital or pharyngeal infection, 34% were positive for NG at ≥1 anatomic site (27% for MSW and 40% for women). Among 161 NG contacts tested at the pharynx, 30% (n = 48) were positive: 20% of 54 MSW (n = 11) and 35% (n = 37) of 107 women. If only urogenital testing were performed, 36% of MSW NG infections (n = 5) and 19% of female NG infections (n = 9) would have remained unidentified. CONCLUSIONS: Pharyngeal NG is relatively common among MSW and women who have been exposed to NG, and likely represents an underdiagnosed reservoir of NG infection. If empiric treatment is abandoned in favor of testing and treating, testing the throats of heterosexuals will be necessary.

Predominance of High-Level Tetracycline-Resistant Neisseria gonorrhoeae in Kenya: Implications for Global Implementation of Doxycycline Postexposure Prophylaxis for Prevention of Sexually Transmitted Infections.

ABSTRACT: Using archived Neisseria gonorrhoeae samples from 2008 to 2012, the prevalence of tet (M) genemediating high-level tetracycline resistance in N. gonorrhoeae was 96% among 50 Kenyan women. Determining the local and national prevalence of gonococcal tetracycline resistance and surveillance of gonococcal antimicrobial resistance can inform the implementation of doxycycline postexposure prophylaxis for STI prevention.

High Prevalence of Rectal Chlamydia and Gonorrhea Among Men Who Have Sex With Men Who Do Not Engage in Receptive Anal Sex.

BACKGROUND: In the United States, annual screening for rectal gonorrhea and chlamydia is only recommended for men who report receptive anal sex (RAS), but other behaviors (e.g., rimming) may lead to rectal Chlamydia trachomatis and Neisseria gonorrhoeae acquisition. METHODS: We enrolled individuals assigned male sex at birth who reported sex with men and denied RAS in the past 2 years or reported RAS 1 to 2 years ago but were tested and treated since last RAS. Participants enrolled in-person at the Sexual Health Clinic in Seattle, Washington (December 2019-July 2022), or online (July 2021-March 2022). Participants completed a survey that asked about 13 non-RAS behaviors and self-collected a rectal swab for gonorrhea/chlamydia nucleic acid amplification testing. We used log binomial regression to estimate the prevalence of rectal gonorrhea/chlamydia (adjusted prevalence ratio [aPR]) by behavior, adjusting for all other behaviors. RESULTS: We enrolled 292 participants (247 in-person and 45 online); 277 (95%) had nucleic acid amplification testing results. Rectal gonorrhea/chlamydia test positivity was 14.1% overall: 10.5% for rectal chlamydia and 4.3% for rectal gonorrhea. Most participants (70%) reported ≥1 behavior that involved direct contact with their anus. We observed a higher risk of rectal chlamydia for those who did versus did not report perianal play at 12 months (aPR, 2.39; 95% confidence interval, 1.10-5.22) and 2 months (aPR, 2.21; 95% confidence interval, 1.02-4.79). This was the only behavior significantly associated with testing positive. CONCLUSIONS: Rectal C. trachomatis and N. gonorrhoeae prevalence was high among men who deny RAS, suggesting other possible routes of acquisition. Rectal screening for those who deny RAS should be made with careful consideration of individual- and population-level effects.

Surfactant-enhanced DNA accessibility to nuclease accelerates phenotypic ß-lactam antibiotic susceptibility testing of Neisseria gonorrhoeae.

Rapid antibiotic susceptibility testing (AST) for Neisseria gonorrhoeae (Ng) is critically needed to counter widespread antibiotic resistance. Detection of nucleic acids in genotypic AST can be rapid, but it has not been successful for ß-lactams (the largest antibiotic class used to treat Ng). Rapid phenotypic AST for Ng is challenged by the pathogen's slow doubling time and the lack of methods to quickly quantify the pathogen's response to ß-lactams. Here, we asked two questions: (1) Is it possible to use nucleic acid quantification to measure the ß-lactam susceptibility phenotype of Ng very rapidly, using antibiotic-exposure times much shorter than the 1- to 2-h doubling time of Ng? (2) Would such short-term antibiotic exposures predict the antibiotic resistance profile of Ng measured by plate growth assays over multiple days? To answer these questions, we devised an innovative approach for performing a rapid phenotypic AST that measures DNA accessibility to exogenous nucleases after exposure to ß-lactams (termed nuclease-accessibility AST [nuc-aAST]). We showed that DNA in antibiotic-susceptible cells has increased accessibility upon exposure to ß-lactams and that a judiciously chosen surfactant permeabilized the outer membrane and enhanced this effect. We tested penicillin, cefixime, and ceftriaxone and found good agreement between the results of the nuc-aAST after 15-30 min of antibiotic exposure and the results of the gold-standard culture-based AST measured over days. These results provide a new pathway toward developing a critically needed phenotypic AST for Ng and additional global-health threats.

Incidence and Duration of Pharyngeal Chlamydia Among a Cohort of Men Who Have Sex With Men.

BACKGROUND: The prevalence of pharyngeal chlamydia is low, but its incidence and duration are unknown. A high incidence or duration may support the role of pharyngeal chlamydia in sustaining chlamydia transmission. METHODS: From March 2016 to December 2018, we enrolled men who have sex with men (MSM) in a 48-week cohort study in Seattle, Washington. Participants self-collected pharyngeal specimens weekly. We tested specimens using nucleic acid amplification testing at the conclusion of the study. In primary analyses, we defined incident pharyngeal chlamydia as >2 consecutive weeks of a positive pharyngeal specimen. In sensitivity analyses, we defined incident chlamydia as >1 week of a positive specimen. We estimated duration of pharyngeal chlamydia, censoring at loss to follow-up, receipt of antibiotics, or end of study. RESULTS: A total of 140 participants contributed 70.5 person-years (PY); 1.4% had pharyngeal chlamydia at enrollment. In primary analyses, there were 8 pharyngeal chlamydia cases among 6 MSM (incidence = 11.4 per 100 PY; 95% confidence interval [CI]: 6.0-21.9). In sensitivity analysis, there were 19 cases among 16 MSM (incidence = 27.1 per 100 PY; 95% CI: 18.5-39.8). The median duration was 6.0 weeks (95% CI: 2.0-undefined) in primary analysis and 2.0 weeks (95% CI: 1.1-6.0) in sensitivity analysis. Duration was shorter for those with a history of chlamydia compared with those without (3.6 vs 8.7 weeks; P = .02). CONCLUSIONS: Pharyngeal chlamydia has a low incidence and duration relative to other extragenital sexually transmitted infections. Its contribution to population-level transmission remains unclear.

The Natural History of Rectal Gonococcal and Chlamydial Infections: The ExGen Study.

BACKGROUND: The duration of rectal gonococcal and chlamydial infection remains unknown. This basic epidemiologic parameter is needed to understand transmission dynamics. METHODS: We conducted a prospective, longitudinal, observational cohort study of 140 men who have sex with men (MSM) at risk of gonorrhea and chlamydia acquisition. For 48 weeks, enrolled men collected rectal swabs (Aptima multi-test kit) at home and responded to an electronic survey about sexual behavior and health conditions weekly. Swabs remained untested until participants completed the study. We used Kaplan-Meier estimates to determine the median duration of infection, censoring infections for treatment, loss to follow-up, and end-of-study. We used log-rank test to compare duration of infection by human immunodeficiency virus (HIV) status, history of infection with gonorrhea or chlamydia, and coinfection with the other pathogen. RESULTS: 140 enrolled MSM contributed 70.5 person-years of follow-up. Eighteen men had 20 incident rectal gonococcal infections, which persisted for 2-23 weeks; 30% were censored for treatment. The estimated median duration of rectal gonorrhea was 9 weeks (95% confidence interval [CI]: 3-12 weeks). Twenty-four men experienced 32 rectal chlamydial infections, persisting between 2 and 42 weeks; 60% were censored. The estimated duration of rectal chlamydia was 13 weeks (95% CI: 6 weeks-undefined). There were no differences in the duration of rectal gonorrhea or chlamydia by HIV status, history of chlamydia/gonorrhea, or coinfection. CONCLUSIONS: On average, rectal gonorrhea and chlamydial infections last 2-3 months, although some infections persisted for 6-11 months. Further understanding into predictors of persistence is needed.

Time to Clearance of Neisseria gonorrhoeae RNA at the Pharynx following Treatment.

The number of days until pharyngeal Neisseria gonorrhoeae nucleic acid amplification test (NAAT) results become negative after treatment remains unknown. Between March 2019 and April 2021, we enrolled men who have sex with men (MSM) who had a clinical positive pharyngeal N. gonorrhoeae Aptima Combo 2 test result but had not yet been treated in a prospective longitudinal cohort study. MSM were enrolled on their day of treatment and self-collected daily pharyngeal specimens for 21 days at home. We used Kaplan-Meier estimates to determine the median time to clearance and the >95% time to clearance and the log rank test for equality to evaluate factors associated with time to clearance. Sixty-four men were enrolled in the study. Analyses excluded 8 men (12.5%) who were N. gonorrhoeae negative by NAAT at enrollment and 11 (17%) who failed to return any home-collected specimens. Among the 45 men included in the analysis, the median time to N. gonorrhoeae NAAT clearance was 3 days (95% confidence interval [CI], 2 to 5 days). Time to clearance for >95% of the cohort was 12 days (95% CI, 10 days to an undefined time). Men with a history of N. gonorrhoeae infection cleared faster than men without such history (8 days versus 17 days for >95% time to clearance; P = 0.03). In the absence of reexposure, positive N. gonorrhoeae Aptima Combo 2 assay results obtained prior to 12 days after treatment are likely false-positive results.

Summary of the Fourth Annual American Sexually Transmitted Diseases Association Workshop on Improving Sexually Transmitted Infection Control Efforts Through Cross-Sector Collaboration.

ABSTRACT: The American Sexually Transmitted Diseases Association has, for several years, been conducting a cross-sector workshop to bring together a variety of stakeholders to develop ideas for collaboratively improving the sexually transmitted infection control efforts in the United States. In this summary, we share the content of discussions and ideas of the fourth annual workshop for future research and potential changes to practice with a focus on diagnostic capacity.

Performance of Patient-collected Specimens for Neisseria gonorrhoeae Culture.

BACKGROUND: Neisseria gonorrhoeae culture is necessary to determine antimicrobial resistance, but typically requires specimen collection by clinicians. We sought to determine the sensitivity of patient-collected specimens for N. gonorrhoeae culture. METHODS: We performed N. gonorrhoeae cultures on paired clinician- and patient-collected specimens from the pharynx (n = 93), rectum (n = 88), endocervix/vagina (n = 89), and urethra/urine (n = 46). We calculated the percent concordance and the kappa statistics for paired-specimen results, and determined the test sensitivity for each specimen type using positivity of either specimen in a pair as a gold standard defining the presence of true infection. RESULTS: At least 1 specimen was positive in 26%, 31%, 61%, and 3% of paired samples in the pharynx, rectum, urethra/urine, and endocervix/vagina, respectively. Patient- and clinician-collected results were highly concordant at the pharynx (95%; kappa = 0.85), rectum (99%; kappa = 0.97), urethra/urine (83%; kappa = 0.87), and endocervix/vagina (100%; kappa = 1.0; P ≤ .005 for all comparisons). Patient-collected pharyngeal and rectal swabs and urine were 92%, 96%, and 96% sensitive, while clinician-collected specimens at these anatomic sites were 87.5%, 100%, and 94% sensitive (P > .05 for all comparisons). Among 24 urine specimens held for 4-22 hours after collection, 100% yielded concordant N. gonorrhoeae culture results, compared to immediate processing. CONCLUSIONS: Patient- and clinician-collected specimens are comparably sensitive for N. gonorrhoeae culture. These findings suggest that patient-collected specimens could be used to expand the availability of gonococcal antimicrobial resistance testing for both clinical and surveillance purposes.