Interferon-Gamma Responses to Chlamydia trachomatis Vaccine Candidate Proteins in Chlamydia-Infected Women with Different Chlamydia Outcomes.

BACKGROUND: Chlamydia trachomatis (CT) testing and treatment strategies have not decreased infection rates, justifying need for a CT vaccine. A murine study showed that a vaccine consisting of MOMP and 4 polymorphic membrane proteins (Pmps E, F, G, H) elicited protective immunity; studies on human cellular immune responses to Pmps are sparse. METHODS: Interferon gamma (IFN-γ) responses to these 5 CT proteins were measured by ELISPOT in PBMCs from women returning for treatment of a positive CT screening test. Responses were compared in those with spontaneous CT clearance vs. persisting infection at baseline and no reinfection vs. reinfection at a 3-month follow-up visit. RESULTS: IFN-γ response to one or more proteins was detected in 39% at baseline and 51.5% at follow-up; PmpE and MOMP most often elicited positive responses. IFN-γ responses to MOMP were detected less often at follow-up vs. baseline in women with reinfection, but were maintained in those without reinfection. Women with spontaneous clearance had a higher magnitude of IFN-γ response to PmpE and MOMP. CONCLUSIONS: IFN-γ responses to these 5 CT vaccine candidate proteins were heterogenous and primarily directed against MOMP and PmpE. Spontaneous clearance of infection and absence of reinfection may be clinical correlates of protection.

Natural Clearance of Chlamydia trachomatis Infection Is Associated With Distinct Differences in Cervicovaginal Metabolites.

BACKGROUND: Natural clearance of Chlamydia trachomatis in women occurs in the interval between screening and treatment. In vitro, interferon-γ (IFN-γ)-mediated tryptophan depletion results in C. trachomatis clearance, but whether this mechanism occurs in vivo remains unclear. We previously found that women who naturally cleared C. trachomatis had lower cervicovaginal levels of tryptophan and IFN-γ compared to women with persisting infection, suggesting IFN-γ-independent pathways may promote C. trachomatis clearance. METHODS: Cervicovaginal lavages from 34 women who did (n = 17) or did not (n = 17) naturally clear C. trachomatis were subjected to untargeted high-performance liquid chromatography mass-spectrometry to identify metabolites and metabolic pathways associated with natural clearance. RESULTS: In total, 375 positively charged metabolites and 149 negatively charged metabolites were annotated. Compared to women with persisting infection, C. trachomatis natural clearance was associated with increased levels of oligosaccharides trehalose, sucrose, melezitose, and maltotriose, and lower levels of indoline and various amino acids. Metabolites were associated with valine, leucine, and isoleucine biosynthesis pathways. CONCLUSIONS: The cervicovaginal metabolome in women who did or did not naturally clear C. trachomatis is distinct. In women who cleared C. trachomatis, depletion of various amino acids, especially valine, leucine, and isoleucine, suggests that amino acids other than tryptophan impact C. trachomatis survival in vivo.

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.

Latest Advances in Laboratory Detection of Mycoplasma genitalium.

Mycoplasma genitalium is an important sexually transmitted pathogen affecting both men and women. Its extremely slow growth in vitro and very demanding culture requirements necessitate the use of molecular-based diagnostic tests for its detection in clinical specimens. The recent availability of U.S. Food and Drug Administration (FDA)-cleared commercial molecular-based assays has enabled diagnostic testing to become more widely available in the United States and no longer limited to specialized reference laboratories. Advances in the knowledge of the epidemiology and clinical significance of M. genitalium as a human pathogen made possible by the availability of molecular-based testing have led to updated guidelines for diagnostic testing and treatment that have been published in various countries. This review summarizes the importance of M. genitalium as an agent of human disease, explains the necessity of obtaining a microbiological diagnosis, describes currently available diagnostic methods, and discusses how the emergence of antimicrobial resistance has complicated treatment alternatives and influenced the development of diagnostic tests for resistance detection, with an emphasis on developments over the past few years.

Retrospective Evaluation of Mycoplasma genitalium Prevalence and Macrolide Resistance in a Study Cohort of Pregnant Women in Birmingham, AL, From 1997 to 2001.

ABSTRACT: In a prospective study conducted in 2020 to 2021, macrolide resistance-associated mutations were found in 41% of pregnant persons in Birmingham, AL, with Mycoplasma genitalium detected. We retrospectively evaluated M. genitalium in 203 pregnant persons participating in a study conducted in 1997 to 2001 in Birmingham and adjacent areas and found a prevalence of 11% (95% confidence interval, 6.9%-15.7%), but no macrolide resistance-associated mutations.

Chlamydia trachomatis -Specific Antibody Responses in Women in Cameroon With Secondary Infertility.

ABSTRACT: The contribution of chlamydia to secondary infertility in women is poorly understood. Among 404 female participants enrolled in a previous study in Cameroon, 142 had secondary infertility (cases) and 262 were pregnant with no history of infertility (controls) , Chlamydia trachomatis seropositivity was 92%. Seropositivity did not significantly differ by case/control status.

HLA-DQB1*06 and Select Neighboring HLA Variants Predict Chlamydia Reinfection Risk.

Associations of HLA class II alleles with genital chlamydial infection outcomes have been reported, especially HLA DQB1*06. However, the potential role of DQB1*06 in influencing reinfection risk has still not been established. The purpose of this study was to determine whether the association of DQB1*06 with chlamydia reinfection was impacted by any other nearby HLA class II variants that were also associated with reinfection. We used next-generation sequencing to map HLA class II variants spanning the HLA-DQ and -DR loci. DQB1*06 as well as DQB1*04 were confirmed as significant predictors of chlamydia reinfection, when controlling for age and percent African ancestry. SKAT analysis revealed one region each in DRB1, DRB5, DQA2, and three intergenic regions that had variants associated with reinfection. Further analyses of these variants revealed that rs112651494 within DRB5 and an intergenic SNP rs617058 in DRB1:DQA1 were significantly associated with reinfection, but this did not impact the significance of the association of DQB1*06 or DQB1*04 with reinfection.

Diagnosis and Management of Uncomplicated Chlamydia trachomatis Infections in Adolescents and Adults: Summary of Evidence Reviewed for the 2021 Centers for Disease Control and Prevention Sexually Transmitted Infections Treatment Guidelines.

To prepare for the development of the 2021 Centers for Disease Control and Prevention (CDC) sexually transmitted infections treatment guidelines, the CDC convened a committee of expert consultants in June 2019 to discuss recent abstracts and published literature on the epidemiology, diagnosis, and management of sexually transmitted infections.This paper summarizes the key questions, evidence, and recommendations for the diagnosis and management of uncomplicated Chlamydia trachomatis (CT) infections in adolescents and adults that were reviewed and discussed for consideration in developing the guidelines. The evidence reviewed mostly focused on efficacy of doxycycline and azithromycin for urogenital, rectal, and oropharyngeal CT infection, CT risk factors in women, performance of CT nucleic acid amplification tests on self-collected meatal specimens in men, and performance of newer CT point-of-care tests.

Chlamydia trachomatis Infection and Seropositivity in Women Reporting Sexual Contact to a Chlamydia-Infected Partner.

ABSTRACT: Among 73 women presenting to a sexually transmitted infection (STI) clinic in Birmingham, Alabama for reported sexual contact to a chlamydia-infected partner, Chlamydia trachomatis was detected in genital specimens in 24 (32.8%), less often in women reporting prior chlamydial infection ( P = 0.001). Most women (93.2%) were C. trachomatis seropositive.

Association of Bacterial Vaginosis With Higher Vaginal Indole Levels.

ABSTRACT: We adapted a simple hydroxylamine-based indole assay to detect indole from stored vaginal swab specimens from women with and without bacterial vaginosis (BV). Women with BV had significantly higher vaginal indole levels compared with women without BV (6451.5 vs 5632.4 µM; P = 0.01), suggesting that indole-producing bacteria are a component of BV.

Evaluation of Clinical, Gram Stain, and Microbiological Cure Outcomes in Men Receiving Azithromycin for Acute Nongonococcal Urethritis: Discordant Cures Are Associated With Mycoplasma genitalium Infection.

BACKGROUND: In men with nongonococcal urethritis (NGU), clinicians and patients rely on clinical cure to guide the need for additional testing/treatment and when to resume sex, respectively; however, discordant clinical and microbiological cure outcomes do occur. How accurately clinical cure reflects microbiological cure in specific sexually transmitted infections (STIs) is unclear. METHODS: Men with NGU were tested for Neisseria gonorrhoeae, Chlamydia trachomatis (CT), Mycoplasma genitalium (MG), Trichomonas vaginalis, urethrotropic Neisseria meningitidis ST-11 clade strains, and Ureaplasma urealyticum (UU). Men received azithromycin 1 g and returned for a 1-month test-of-cure visit. In MG infections, we evaluated for the presence of macrolide resistance-mediating mutations (MRMs) and investigated alternate hypotheses for microbiological treatment failure using in situ shotgun metagenomic sequencing, phylogenetic analysis, multilocus sequence typing analyses, and quantitative PCR. RESULTS: Of 280 men with NGU, 121 were included in this analysis. In the monoinfection group, 52 had CT, 16 had MG, 7 had UU, 10 had mixed infection, and 36 men had idiopathic NGU. Clinical cure rates were 85% for CT, 100% for UU, 50% for MG, and 67% for idiopathic NGU. Clinical cure accurately predicted microbiological cure for all STIs, except MG. Discordant results were significantly associated with MG-NGU and predominantly reflected microbiological failure in men with clinical cure. Mycoplasma genitalium MRMs, but not MG load or strain, were strongly associated with microbiological failure. CONCLUSIONS: In azithromycin-treated NGU, clinical cure predicts microbiological cure for all STIs, except MG. Nongonococcal urethritis management should include MG testing and confirmation of microbiological cure in azithromycin-treated MG-NGU when MRM testing is unavailable.

Chlamydial Pgp3 Seropositivity and Population-Attributable Fraction Among Women With Tubal Factor Infertility.

BACKGROUND: Chlamydial infection is associated with tubal factor infertility (TFI); however, assessment of prior chlamydial infection and TFI is imperfect. We previously evaluated a combination of serological assays for association with TFI. We now describe the chlamydial contribution to TFI using a newer Chlamydia trachomatis Pgp3-enhanced serological (Pgp3) assay. METHODS: In our case-control study of women 19 to 42 years old with hysterosalpingogram-diagnosed TFI (cases) and non-TFI (controls) in 2 US infertility clinics, we assessed possible associations and effect modifiers between Pgp3 seropositivity and TFI using adjusted odds ratios with 95% confidence intervals (CIs) stratified by race. We then estimated the adjusted chlamydia population-attributable fraction with 95% CI of TFI. RESULTS: All Black (n = 107) and 618 of 620 non-Black women had Pgp3 results. Pgp3 seropositivity was 25.9% (95% CI, 19.3%-33.8%) for non-Black cases, 15.2% (95% CI, 12.3%-18.7%) for non-Black controls, 66.0% (95% CI, 51.7%-77.8%) for Black cases, and 71.7% (95% CI, 59.2%-81.5%) for Black controls. Among 476 non-Black women without endometriosis (n = 476), Pgp3 was associated with TFI (adjusted odds ratio, 2.6 [95% CI, 1.5-4.4]), adjusting for clinic, age, and income; chlamydia TFI-adjusted population-attributable fraction was 19.8% (95% CI, 7.7%-32.2%) in these women. Pgp3 positivity was not associated with TFI among non-Black women with endometriosis or among Black women (regardless of endometriosis). CONCLUSIONS: Among non-Black infertile women without endometriosis in these clinics, 20% of TFI was attributed to chlamydia. Better biomarkers are needed to estimate chlamydia TFI PAF, especially in Black women.

A Commentary on Current Diagnostic Challenges and Research Needs for Evaluating Reproductive Sequelae of Sexually Transmitted Infections.

Advancing the understanding of pelvic inflammatory disease (PID) requires access to advanced diagnostic approaches for evaluating reproductive sequelae of sexually transmitted infections (STIs). Current limitations of clinical criteria and advanced imaging technologies for diagnosing reproductive sequelae make diagnosis and surveillance of PID a challenge. We summarize and comment on major challenges in diagnostic evaluation of reproductive sequelae: limited point-of-care clinical diagnostic options for reproductive sequelae, economic and geographical obstacles to accessing state-of-the-art diagnostics, an expanding list of STIs that may cause reproductive sequelae and the complexities in evaluating them, and the need for coordinated research efforts to systematically evaluate biomarkers with gold-standard, well-defined specimens and associated clinical data. The future use of biomarkers in readily accessible mucosal or blood-derived specimens as a noninvasive approach to determining STI etiologies may be fruitful and requires more research. Biomarkers under consideration include cytokines, STI-specific antibody responses, and mRNA transcriptional profiles of inflammatory markers.

What Can Serology Tell Us About the Burden of Infertility in Women Caused by Chlamydia?

Chlamydia trachomatis (CT) causes pelvic inflammatory disease, which may result in tubal factor infertility (TFI) in women. Serologic assays may be used to determine the proportion of women with and without TFI who have had previous CT infection and to generate estimates of infertility attributable to chlamydia. Unfortunately, most existing CT serologic assays are challenged by low sensitivity and, sometimes, specificity for prior CT infection; however, they are currently the only available tests available to detect prior CT infection. Modeling methods such as finite mixture modeling may be a useful adjunct to quantitative serologic data to obtain better estimates of CT-related infertility. In this article, we review CT serological assays, including the use of antigens preferentially expressed during upper genital tract infection, and suggest future research directions. These methodologic improvements, coupled with creation of new biomarkers for previous CT infection, should improve our understanding of chlamydia's contribution to female infertility.

Host Genetic Risk Factors for Chlamydia trachomatis-Related Infertility in Women.

BACKGROUND: Chlamydia trachomatis (Ct) infection ascending to the upper genital tract can cause infertility. Direct association of genetic variants as contributors is challenging because infertility may not be diagnosed until years after infection. Investigating the intermediate trait of ascension bridges this gap. METHODS: We identified infertility genome-wide association study (GWAS) loci using deoxyribonucleic acid from Ct-seropositive cisgender women in a tubal factor infertility study and Ct-infected cisgender women from a longitudinal pelvic inflammatory disease cohort with known fertility status. Deoxyribonucleic acid and blood messenger ribonucleic acid from 2 additional female cohorts with active Ct infection and known endometrial infection status were used to investigate the impact of infertility single-nucleotide polymorphisms (SNPs) on Ct ascension. A statistical mediation test examined whether multiple infertility SNPs jointly influenced ascension risk by modulating expression of mediator genes. RESULTS: We identified 112 candidate infertility GWAS loci, and 31 associated with Ct ascension. The SNPs altered chlamydial ascension by modulating expression of 40 mediator genes. Mediator genes identified are involved in innate immune responses including type I interferon production, T-cell function, fibrosis, female reproductive tract health, and protein synthesis and degradation. CONCLUSIONS: We identified Ct-related infertility loci and their potential functional effects on Ct ascension.

Predicting the Probability of Chlamydia Reinfection in African American Women Using Immunologic and Genetic Determinants in a Bayesian Model.

BACKGROUND: African Americans have the highest rates of Chlamydia trachomatis (CT) infection in the United States and also high reinfection rates. The primary objective of this study was to develop a Bayesian model to predict the probability of CT reinfection in African American women using immunogenetic data. METHODS: We analyzed data from a cohort of CT-infected African American women enrolled at the time they returned to a clinic in Birmingham, AL, for the treatment of a positive routine CT test result. We modeled the probability of CT reinfection within 6 months after treatment using logistic regression in a Bayesian framework. Predictors of interest were presence or absence of an HLA-DQB1*06 allele and CT-specific CD4+ IFN-γ response, both of which we had previously reported were independently associated with CT reinfection risk. RESULTS: Among 99 participants evaluated, the probability of reinfection for those with a CT-specific CD4+ IFN-γ response and no HLA-DQB1*06 alleles was 14.1% (95% credible interval [CI], 3.0%-45.0%), whereas the probability of reinfection for those without a CT-specific CD4+ IFN-γ response and at least one HLA-DQB1*06 allele was 61.5% (95% CI, 23.1%-89.7%). CONCLUSIONS: Our model demonstrated that presence or absence of an HLA-DQB1*06 allele and CT-specific CD4+ IFN-γ response can have an impact on the predictive probability of CT reinfection in African American women.

Mycoplasma genitalium Infection in Young Women Without Urogenital Symptoms Presenting to a Community-Based Emergency Department in Birmingham, Alabama.

ABSTRACT: We used the Food and Drug Administration-cleared Aptima Mycoplasma genitalium assay to evaluate for M. genitalium infection among young women without urogenital symptoms presenting to a community-based emergency department in Birmingham, Alabama, between August 2016 to August 2019 for evaluation of nongynecological concerns. M. genitalium was detected in 23 (14.8%) of 155 women.

Tubal Factor Infertility, In Vitro Fertilization, and Racial Disparities: A Retrospective Cohort in Two US Clinics.

BACKGROUND: Nearly 14% of US women report any lifetime infertility which is associated with health care costs and psychosocial consequences. Tubal factor infertility (TFI) often occurs as a result of sexually transmitted diseases and subsequent pelvic inflammatory disease. We sought to evaluate for and describe potential racial disparities in TFI and in vitro fertilization (IVF) prevalence. METHODS: Records of women aged 19 to 42 years in our retrospective cohort from 2 US infertility clinics were reviewed. We calculated TFI prevalence, IVF initiation prevalence, and prevalence ratios (PRs), with 95% confidence intervals (CIs) for each estimate, overall and by race. RESULTS: Among 660 infertile women, 110 (16.7%; 95% CI, 13.8-19.5%) had TFI which was higher in Black compared with White women (30.3% [33/109] vs 13.9% [68/489]; PR, 2.2 [95% CI, 1.5-3.1]). For women with TFI, IVF was offered to similar proportions of women by race (51.5% [17/33] vs 52.9% [36/68] for Black vs White women); however, fewer Black than White women with TFI started IVF (6.7% [1/15] vs 31.0% [9/29]; PR, 0.2 [95% CI, 0-1.0]), although the difference was not statistically different. CONCLUSIONS: Tubal factor infertility prevalence was 2-fold higher among Black than White women seeking care for infertility. Among women with TFI, data suggested a lower likelihood of Black women starting IVF than White women. Improved sexually transmitted disease prevention and treatment might ameliorate disparities in TFI.

Prevalence of Chlamydia trachomatis Infection in Young Women and Associated Predictors.

BACKGROUND: Chlamydia trachomatis (CT) infection remains highly prevalent, and young women are disproportionately affected. Most CT-infected women are asymptomatic, and their infection often goes unrecognized and untreated. We hypothesized that testing for active CT infection with molecular diagnostics and obtaining a reported history of CT infection underestimate the prevalence of current and past CT infection, and incorporating serum CT antibody testing in addition to these other prevalence measures would generate more accurate estimates of the prevalence of CT infection in asymptomatic young women. METHODS: We enrolled 362 asymptomatic women aged 16 to 29 years at 4 different clinical settings in Birmingham, AL, between August 2016 and January 2020 and determined the prevalence of CT infection based on having 1 or more of the following prevalence measures: an active urogenital CT infection based on molecular testing, reported prior CT infection, and/or being CT seropositive. Multivariable regression analysis was used to determine predictors of the prevalence of CT infection after adjustment for participant characteristics. RESULTS: The prevalence of CT infection was 67.7% (95% confidence interval, 62.6%-72.5%). Addition of CT antibody testing to the other individual prevalence measures more than doubled the CT infection prevalence. Non-Hispanic Black race, reported prior gonorrhea, and reported prior trichomoniasis predicted a higher prevalence of CT infection. CONCLUSIONS: More than half of women were unaware of ever having CT infection, suggesting many were at risk for CT-associated reproductive complications. These data reinforce the need to adhere to chlamydia screening guidelines and to increase screening coverage in those at risk.

Prevalence of Mycoplasma genitalium Infection, Antimicrobial Resistance Mutations, and Symptom Resolution Following Treatment of Urethritis.

BACKGROUND: Antimicrobial resistance in Mycoplasma genitalium (MG), a cause of urethritis, is a growing concern. Yet little is known about the geographic distribution of MG resistance in the United States or about its associated clinical outcomes. We evaluated the frequency of MG among men with urethritis, resistance mutations, and posttreatment symptom persistence. METHODS: We enrolled men presenting with urethritis symptoms to 6 US sexually transmitted disease (STD) clinics during June 2017-July 2018; men with urethritis were eligible for follow-up contact and, if they had persistent symptoms or MG, a chart review. Urethral specimens were tested for MG and other bacterial STDs. Mutations in 23S ribosomal ribonucleic acid (rRNA) loci (macrolide resistance-associated mutations [MRMs]) and in parC and gyrA (quinolone-associated mutations) were detected by targeted amplification/Sanger sequencing. RESULTS: Among 914 evaluable participants, 28.7% (95% confidence interval [CI], 23.8-33.6) had MG. Men with MG were more often Black (79.8% vs 66%, respectively), <30 years (72.9% vs 56.1%, respectively), and reported only female partners (83.7% vs 74.2%, respectively) than men without MG. Among MG-positive participants, 64.4% (95% CI, 58.2-70.3%) had MRM, 11.5% (95% CI, 7.9-16.0%) had parC mutations, and 0% had gyrA mutations. Among participants treated with azithromycin-based therapy at enrollment and who completed the follow-up survey, persistent symptoms were reported by 25.8% of MG-positive/MRM-positive men, 13% of MG-positive/MRM-negative men, and 17.2% of MG-negative men. CONCLUSIONS: MG infection was common among men with urethritis; the MRM prevalence was high among men with MG. Persistent symptoms following treatment were frequent among men both with and without MG.