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 is 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.

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.

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.

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.