Chlamydia trachomatis seroassays used in epidemiologic research: a narrative review and practical considerations.

Chlamydia trachomatis (CT) is a sexually transmitted infection that can lead to adverse reproductive health outcomes. CT prevalence estimates are primarily derived from screening using nucleic acid amplification tests (NAATs). However, screening guidelines in the United States only include particular subpopulations, and NAATs only detect current infections. In contrast, seroassays identify past CT infections which are important for understanding the public health impacts of CT, including pelvic inflammatory disease and tubal factor infertility. Older seroassays have been plagued by low sensitivity and specificity and have not been validated using a consistent reference measure, making it challenging to compare studies, define the epidemiology of CT and determine the effectiveness of control programs. Newer seroassays have better performance characteristics. This narrative review summarizes the "state of the science" for CT seroassays that have been applied in epidemiologic studies and provides practical considerations for interpreting the literature and employing seroassays in future research.

Antibodies from chlamydia-infected individuals facilitate phagocytosis via Fc receptors.

Non-neutralizing functions of antibodies, including phagocytosis, may play a role in Chlamydia trachomatis (CT) infection, but these functions have not been studied and assays are lacking. We utilized a flow-cytometry-based assay to determine whether serum samples from a well-characterized cohort of CT-infected and naïve control individuals enhanced phagocytosis via Fc-receptor-expressing THP-1 cells, and whether this activity correlated with antibody titers. Fc-receptor-mediated phagocytosis was detected only in CT+ donors. Phagocytosis generally did not correlate well with antibody titer. In addition, we found that complement from both CT+ and negative individuals enhanced phagocytosis of CT into primary neutrophils. These results suggest that anti-CT antibodies can have functions that are not reflected by titer. This method could be used to quantitively measure Fc-receptor-mediated function of anti-CT antibodies or complement activity and could reveal new immune correlates of protection.

Trends in Chlamydia trachomatis Treatment Prescribing Practices in King County, Washington, 2010-2018.

BACKGROUND: In 2021, national Chlamydia trachomatis (CT) treatment guidelines changed from recommending either azithromycin (1 g; single dose) or doxycycline (100 mg twice daily for 7 days) to recommending only doxycycline as first-line treatment. The distribution and trends in CT prescribing practices before the guidelines change is largely unknown. METHODS: We conducted a trends analysis using Washington STD surveillance data. We included all female cases of urogenital CT 15 years or older who resided in King County and were diagnosed between 2010 and 2018. Surveillance data included information on demographics, sexual history, clinical features, diagnosing facility (eg, emergency department, family planning), and treatment regimen. We conducted descriptive analyses to examine trends in prescribing practices over time and by facility type. We used Poisson regression to examine the association between CT case characteristics and receipt of receipt of azithromycin. RESULTS: There were 36,830 cases of female urogenital CT during the study period. The percent of cases receiving azithromycin increased significantly from 86% in 2010 to 94% in 2018; the percent receiving doxycycline decreased from 13% to 5%. Five of the 8 facility types prescribed azithromycin to >95% of CT cases by 2018. Cases who were younger or cases of color were more likely to receive azithromycin (versus doxycycline) compared with older and White cases, respectively. CONCLUSIONS: A substantial shift in CT prescribing practices will be needed to adhere to new CT treatment guidelines. Our findings highlight the need for targeted provider education and training to encourage the transition to doxycycline use.

Impact of Text-Based Monthly Check-Ins on Pre-Exposure Prophylaxis Retention at a Sexual Health Clinic.

ABSTRACT: We conducted a retrospective cohort study of preexposure prophylaxis patients at the municipal Sexual Health Clinic in Seattle-King County, Washington from 2019 to 2021 to determine whether monthly check-in text messages impacted 4- and 6-month pre-exposure prophylaxis retention. Monthly check-ins did not appear to improve retention above and beyond open-ended texting and appointment reminders.

The Relationship Between Insertive Oral and Anal Sex and Select Measures of the Composition of the Urethral Microbiota Among Men Who Have Sex With Men.

BACKGROUND: Sexual behavior may influence the composition of the male urethral microbiota, but this hypothesis has not been tested in longitudinal studies of men who have sex with men (MSM). METHODS: From December 2014 to July 2018, we enrolled MSM with nongonococcal urethritis (NGU) attending a sexual health clinic. Men attended 5 in-clinic visits at 3-week intervals, collected weekly urine specimens at home, and reported daily antibiotics and sexual activity on weekly diaries. We applied broad-range 16S rRNA gene sequencing to urine. We used generalized estimating equations to estimate the association between urethral sexual exposures in the prior 7 days (insertive oral sex [IOS] only, condomless insertive anal intercourse [CIAI] only, IOS with CIAI [IOS + CIAI], or none) and Shannon index, number of species (observed, oral indicator, and rectal indicator), and specific taxa, adjusting for recent antibiotics, age, race/ethnicity, HIV, and preexposure prophylaxis. RESULTS: Ninety-six of 108 MSM with NGU attended ≥1 follow-up visit. They contributed 1140 person-weeks of behavioral data and 1006 urine specimens. Compared with those with no urethral sexual exposures, those with IOS only had higher Shannon index ( P = 0.03 ) but similar number of species and presence of specific taxa considered, adjusting for confounders; the exception was an association with Haemophilus parainfluenzae . CIAI only was not associated with measured aspects of the urethral microbiota. IOS + CIAI was only associated with presence of H. parainfluenzae and Haemophilus . CONCLUSIONS: Among MSM after NGU, IOS and CIAI did not seem to have a substantial influence on measured aspects of the composition of the urethral microbiota.

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.

A Quantitative Intersectionality Analysis of HIV/STI Prevention and Healthcare Access Among Transgender and Nonbinary People.

BACKGROUND: Transgender and nonbinary people experience substantial barriers to accessing healthcare, including prevention of HIV and other sexually transmitted infections (HIV/STI), due to structural inequities. We examined differences in insurance, HIV/STI prevalence, testing, and preexposure prophylaxis use among transgender and nonbinary people living in Washington State by race and ethnicity and gender. METHODS: We pooled data from five 2019-2021 Washington State HIV/STI surveillance data sources to obtain a large and diverse sample of 1648 transgender and nonbinary participants. We calculated the risk difference (RD) for each outcome and used Poisson regression to estimate a surrogate measure of additive interaction-attributable proportion (AP)-that measures the proportion of the excess prevalence of the outcome observed at the intersection of gendered and racialized experience, beyond that expected from gender or race and ethnicity alone. RESULTS: Participants reported overall high levels of poverty (29% incomes <$15,000 and 7% unstable housing). Certain groups, especially racial/ethnic minority transgender women, were disproportionately impacted by HIV/STIs (RDs from 20% to 43% and APs from 50% to 85%) and less likely to currently have insurance (RDs from 25% to 39% and APs from 74% to 93%) than that expected based on gendered or racialized experience alone. CONCLUSIONS: Our findings highlight the heterogeneity in insurance access, HIV/STI positivity, and prevention utilization within transgender communities. We observed that a large proportion of increased HIV/STI prevalence among racial/ethnic minority transgender women was attributable to the intersection of gender and race and ethnicity. Our findings highlight the importance of trans-inclusive models of HIV/STI prevention that address multilevel barriers rooted in cissexism and structural racism.

Inadequate performance of a risk score to predict asymptomatic Neisseria gonorrhoeae and Chlamydia trachomatis infection among cisgender men who have sex with men.

OBJECTIVES: Epidemiological treatment of persons who are sexual contacts to partners with Neisseria gonorrhoeae (NG) and Chlamydia trachomatis (CT) often results in treatment of uninfected persons, which may increase the risk of antibiotic-resistant infections. We sought to identify the predictors of NG and/or CT infections to develop a risk score that could be used to limit epidemiological treatment to persons most likely to have these infections. METHODS: We included visits to the Public Health - Seattle & King County Sexual Health Clinic by asymptomatic cisgender men who have sex with men (MSM) aged ≥18 who presented as a sexual contact to partner(s) with CT or NG infection between 2011 and 2019. We used logistic regression to estimate the odds of CT and/or NG infections associated with demographic and clinical predictors, selecting the final set of predictors using the Akaike information criteria and obtaining score weights from model coefficients. We used a cross-validation approach to obtain average model discrimination from each of 10 models, leaving out 10% of the data, and evaluated sensitivity and specificity at various score cut-offs. RESULTS: The final model for predicting NG or CT infection included seven predictors (age <35 years, HIV status, receptive oral sex in the prior 2 months, CT diagnosis, condomless receptive anal intercourse, condomless insertive anal intercourse and methamphetamine use in the prior 12 months). Model discrimination, as measured by the receiver operating curve, was 0.60 (95% CI 0.54 to 0.66). Sensitivity for detection of infection was ≥90% for scores ≥3, ≥5 and ≥7; specificity for these cut-offs was <16%. At scores ≥9, ≥12 and ≥14, specificity increased but sensitivity decreased to ≤76%. CONCLUSIONS: Our risk score did not sufficiently discriminate between asymptomatic MSM with and without NG/CT infection. Additional studies evaluating epidemiological treatment as a standard of care in diverse populations are needed to guide best practices in the management of contacts to NG/CT infection.

Using infection prevalence, seroprevalence and case report data to estimate chlamydial infection incidence.

OBJECTIVES: To measure the effectiveness of chlamydia control strategies, we must estimate infection incidence over time. Available data, including survey-based infection prevalence and case reports, have limitations as proxies for infection incidence. We therefore developed a novel method for estimating chlamydial incidence. METHODS: We linked a susceptible infectious mathematical model to serodynamics data from the National Health and Nutritional Examination Survey, as well as to annual case reports. We created four iterations of this model, varying assumptions about how the method of infection clearance (via treatment seeking, routine screening or natural clearance) relates to long-term seropositivity. Using these models, we estimated annual infection incidence for women aged 18-24 and 25-37 years in 2014. To assess model plausibility, we also estimated natural clearance for the same groups. RESULTS: Of the four models we analysed, the model that best explained the empirical data was the one in which longer-lasting infections, natural clearance and symptomatic infections all increased the probability of long-term seroconversion. Using this model, we estimated 5910 (quartile (Q)1, 5330; Q3, 6500) incident infections per 100 000 women aged 18-24 years and 2790 (Q1, 2500; Q3, 3090) incident infections per 100 000 women aged 25-37 years in 2014. Furthermore, we estimated that natural clearance rates increased with age. CONCLUSIONS: Our method can be used to estimate the number of chlamydia infections each year, and thus whether infection incidence increases or decreases over time and after policy changes. Furthermore, our results suggest that clearance via medical intervention may lead to short-term or no seroconversion, and the duration of untreated chlamydial infection may vary with age, underlining the complexity of chlamydial infection dynamics.

Heterogeneity in HIV/Sexually Transmitted Infection Prevalence and Prevention Among the Partners of Transgender and Nonbinary People.

BACKGROUND: Transgender and nonbinary (TNB) people are diverse in their sexual orientation and partnerships. We describe the epidemiology of HIV/sexually transmitted infection (STI) prevalence and prevention utilization among the partners of TNB people in Washington State. METHODS: We pooled data from five 2017 to 2021 cross-sectional HIV surveillance data sources to generate a large sample of TNB people and cisgender people who had a TNB partner in the past year. We described characteristics of recent partners of trans women, trans men, and nonbinary people and used Poisson regression to assess if having a TNB partner was associated with self-reported HIV/STIs prevalence, testing, and preexposure prophylaxis (PrEP) use. RESULTS: Our analysis included 360 trans women, 316 trans men, 963 nonbinary people, 2896 cis women, and 7540 cis men. Overall, 9% of sexual minority cis men, 13% of sexual minority cis women, and 36% of TNB participants reported having any TNB partners. There was significant heterogeneity in HIV/STI prevalence, testing, and PrEP use among the partners of TNB people by study participant gender and the gender of their sex partners. In regression models, having a TNB partner was associated with a higher likelihood of HIV/STI testing and PrEP use but was not associated with higher HIV prevalence. CONCLUSIONS: We observed significant heterogeneity in HIV/STI prevalence and preventative behaviors among the partners of TNB people. Given that TNB people are diverse in their sexual partnerships, there is a need to better understand individual-, dyad-, and structural-level factors that facilitate HIV/STI prevention across these diverse partnerships.

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.

Patterns of Pre-exposure Prophylaxis (PrEP) Use in a Population Accessing PrEP in Jackson, Mississippi.

Pre-exposure prophylaxis (PrEP) persistence is suboptimal in the United States. In the Deep South, a region with high rates of new HIV diagnosis, patterns of PrEP discontinuation remain unexplored. We evaluated data from a clinic-based PrEP program in Jackson, Mississippi and included patients initiating PrEP between August 2018 and April 2021. We considered patients to have a gap in PrEP coverage if they had at least 30 days without an active PrEP prescription; those who restarted PrEP after 30 days were classified as 'stopped and restarted' and those who never obtained a new PrEP prescription were classified as 'stopped and did not restart'. Patients without a gap in coverage were considered 'continuously on PrEP'. We estimated median time to first PrEP discontinuation and examined factors associated with time to first PrEP discontinuation. Of 171 patients who received an initial 90-day PrEP prescription; 75% were assigned male at birth and 74% identified as Black. The median time to first discontinuation was 90 days (95% CI 90-114). Twenty-two percent were continuously on PrEP, 28% stopped and restarted (median time off PrEP = 102 days), and 50% stopped and did not restart. Associations with early PrEP stoppage were notable for patients assigned sex female vs male (adjusted hazard ratio [aHR] = 1.6, 95% CI 1.0-2.5) and those living over 25 miles from clinic vs. 0-10 miles (aHR 1.89, 95% CI 1.2-3.0). Most patients never refilled an initial PrEP prescription though many patients re-started PrEP. Interventions to improve persistence and facilitate re-starts are needed.

Association between any underlying health condition and COVID-19-associated hospitalization by age group, Washington State, 2020-2021: a retrospective cohort study.

BACKGROUND: Presence of at least one underlying health condition (UHC) is positively associated with severe COVID-19, but there is limited research examining this association by age group, particularly among young adults. METHODS: We examined age-stratified associations between any UHC and COVID-19-associated hospitalization using a retrospective cohort study of electronic health record data from the University of Washington Medicine healthcare system for adult patients with a positive SARS-CoV-2 test from February 29, 2020, to March 13, 2021. Any UHC was defined as documented diagnosis of at least one UHC identified by the CDC as a potential risk factor for severe COVID-19. Adjusting for sex, age, race and ethnicity, and health insurance, we estimated risk ratios (aRRs) and risk differences (aRDs), overall and by age group (18-39, 40-64, and 65 + years). RESULTS: Among patients aged 18-39 (N = 3,249), 40-64 (N = 2,840), 65 + years (N = 1,363), and overall (N = 7,452), 57.5%, 79.4%, 89.4%, and 71.7% had at least one UHC, respectively. Overall, 4.4% of patients experienced COVID-19-associated hospitalization. For all age groups, the risk of COVID-19-associated hospitalization was greater for patients with any UHC vs. those without (18-39: 2.2% vs. 0.4%; 40-64: 5.6% vs. 0.3%; 65 + : 12.2% vs. 2.8%; overall: 5.9% vs. 0.6%). The aRR comparing patients with vs. those without UHCs was notably higher for patients aged 40-64 years (aRR [95% CI] for 18-39: 4.3 [1.8, 10.0]; 40-64: 12.9 [3.2, 52.5]; 65 + : 3.1 [1.2, 8.2]; overall: 5.3 [3.0, 9.6]). The aRDs increased across age groups (aRD [95% CI] per 1,000 SARS-CoV-2-positive persons for 18-39: 10 [2, 18]; 40-64: 43 [33, 54]; 65 + : 84 [51, 116]; overall: 28 [21, 35]). CONCLUSIONS: Individuals with UHCs are at significantly increased risk of COVID-19-associated hospitalization regardless of age. Our findings support the prevention of severe COVID-19 in adults with UHCs in all age groups and in older adults aged 65 + years as ongoing local public health priorities.

Diverging Neisseria gonorrhoeae Morbidity in Non-Hispanic Black and White Females: Application of Group-Based Trajectory Modeling to Trends in County-Level Morbidity 2003-2018.

National trends in gonorrhea rates may obscure informative local variations in morbidity. We used group-based trajectory models to identify groups of counties with similar gonorrhea rate trajectories among non-Hispanic White (NHW) and non-Hispanic Black (NHB) females using county-level data on gonorrhea cases in US females from 2003 to 2018. We assessed models with 1-15 groups and selected final models based on fit statistics and identification of divergent trajectory groups with distinct intercepts and/or slopes. We mapped counties by assigned trajectory group and examined the association of county characteristics with group membership. We identified 7 distinct gonorrhea trajectory groups for NHW females and 9 distinct trajectory groups for NHB females. All identified groups for NHW female morbidity experienced increasing gonorrhea rates with a limited range (11.6-183.3/100,000 NHW females in 2018); trajectories of NHB female morbidity varied widely in rates (146.6-966.0/1000 NHB females in 2018) and included 3 groups of counties that experienced a net decline in gonorrhea rates. Counties with higher NHW female morbidity had lower adult sex ratios, lower health insurance coverage, and lower marital rates among NHW adults. Counties with higher NHB female morbidity were more urban, experienced higher rates of poverty, and had lower rates of marriage among NHB adults. Morbidity patterns did not always follow geographic proximity, which could be explained by variation in social determinants of health. Our results demonstrated a highly heterogenous gonorrhea epidemic among NHW and NHB US females, which should prompt further analysis into the differential drivers of gonorrhea morbidity.

Frequency and Combination of Sequential Sexual Acts That May Lead to Sexually Transmitted Infections at Different Anatomic Sites Within the Same Person.

Modeling studies suggest that transmission of gonorrhea and chlamydia to multiple anatomic sites within the same person is necessary to reproduce observed high rates of extragenital gonorrhea/chlamydia. Limited empiric behavioral data support this idea. In this cross-sectional study, we enrolled individuals assigned male at birth who reported sex with men (MSM) and denied receptive anal sex (RAS) in the past 2 years. Participants enrolled in-person at the Sexual Health Clinic in Seattle, Washington (December 2019-September 2021) or online (July 2021-September 2021), and completed a sexual history questionnaire that asked about specific sexual acts and sequence of those acts during their last sexual encounter. We enrolled 210 MSM during the 16-month recruiting period. The median number of sex acts reported at last sexual encounter was 4 (interquartile range 3-5). The most commonly reported acts at last sex were: kissing (83%), receiving oral sex (82%), and insertive anal sex (65%). There was substantial variability in the sequence of acts reported; no unique sequence of sex acts was reported by more than 12% of the population. Ninety percent of participants reported sequences of behaviors that could lead to gonorrhea or chlamydia transmission within the same person (respondent or partner); the most common of these combinations was kissing followed by receiving oral sex (64% reporting). Engaging in multiple sex acts within a single sexual encounter is common and may lead to gonorrhea/chlamydia transmission within the same person. This complicates empiric measurements of transmission probabilities needed to estimate population-level transmission.

The Incidence Rate of Sexual Behaviors Among Cisgender Men Who Have Sex with Men Attending a Sexual Health Clinic.

Although nuanced parameterization of sexual behavior may improve estimates from mathematical models of human immunodeficiency virus and sexually transmitted infection transmission, prospective estimates of the incidence of specific sexual behaviors among men who have sex with men (MSM) are limited. From December 2014 to July 2018, MSM with and without nongonococcal urethritis (NGU) completed weekly diaries over 3-12 weeks. Incidence rates of any sex, receptive anal sex, insertive anal sex, insertive oral sex, receptive rimming, and receptive hand-penile contact were 1.19, 0.28, 0.66, 0.90, 0.24, and 0.85 episodes per person-week, respectively, among 104 MSM with NGU at baseline, and 1.33, 0.54, 0.32, 0.95, 0.44, and 0.88 episodes per person-week, respectively, among 25 MSM without NGU at baseline. Most receptive anal sex (NGU + 83%, NGU - 86%) and insertive anal sex (NGU + 85%, NGU - 76%) episodes were condomless. MSM engaged in sex just over once per week, and condom use was infrequent. Insertive oral sex and receptive hand-penile contact were the most common behaviors.

Persistence in a pharmacist-led, same-day PrEP program in Mississippi: a mixed-methods study.

INTRODUCTION: Mississippi has one of the highest rates of HIV in the United States but low PrEP uptake. Understanding patterns of PrEP use can improve PrEP initiation and persistence. METHODS: This is a mixed-method evaluation of a PrEP program in Jackson, Mississippi. Between November 2018-December 2019, clients at high risk for HIV attending a non-clinical testing site were referred to a pharmacist for same-day PrEP initiation. The pharmacist provided a 90-day PrEP prescription and scheduled a follow-up clinical appointment within three months. We linked client records from this visit to electronic health records from the two largest PrEP clinics in Jackson to determine linkage into ongoing clinical care. We identified four distinct PrEP use patterns, which we used for qualitative interview sampling: 1) filled a prescription and linked into care within three months; 2) filled a prescription and linked into care after three months; 3) filled a prescription and never linked into care; and 4) never filled a prescription. In 2021, we purposively sampled patients in these four groups for individual interviews to ascertain barriers and facilitators to PrEP initiation and persistence, using guides informed by the Theory of Planned Behavior. RESULTS: There were 121 clients evaluated for PrEP; all were given a prescription. One-third were less than 25 years old, 77% were Black, and 59% were cisgender men who have sex with men. One-quarter (26%) never filled their PrEP prescription, 44% picked up the prescription but never linked into clinical care, 12% linked into care at some point after three months (resulting in a gap in PrEP coverage), and 18% linked into care within 3 months. We interviewed 26 of 121 clients. Qualitative data revealed that cost, stigmas related to sexuality and HIV, misinformation about PrEP, and perceived side effects were barriers to uptake and persistence. Individuals' desire to stay healthy and the support of PrEP clinic staff were facilitators. CONCLUSIONS: The majority of individuals given a same-day PrEP prescription either never started PrEP or stopped PrEP within the first three months. Addressing noted barriers of stigma and misinformation and reducing structural barriers may increase PrEP initiation and persistence.

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.

A Novel Curriculum Review Process for Initiating the Incorporation of Antiracist Principles Into Epidemiology Course Work.

There is growing acknowledgement of the legacy of White supremacy and racism in the discipline of epidemiology. Our department in the University of Washington School of Public Health undertook a systematic effort to begin addressing institutionalized racism and inclusive teaching in our courses. In July 2020, we introduced a new tool (the "Course Development Plan" (CDP)) to advance our curriculum. The CDP includes 2 components: 1) a guideline document that provides strategies on how to modify curricula and classroom teaching to incorporate antiracism and principles of equity, diversity, and inclusion (EDI); and 2) a structured worksheet for instructors to share EDI and antiracism practices they already incorporate and practices they plan to incorporate into their classes. Worksheets for each class are submitted prior to the beginning of the quarter and are reviewed by a peer faculty member and at least 1 epidemiology student; reviewers provide written feedback on the CDP worksheet. Further evaluation to assess the impact of the CDP process on classroom climate is ongoing. In this commentary, we discuss our department's efforts, the challenges we faced, and our hopes for next steps.