Project description:BACKGROUND:Sexual transmission rates of Chlamydia trachomatis (Ct) cannot be measured directly; however, the study of concordance of Ct infection in sexual partnerships (dyads) can help to illuminate factors influencing Ct transmission. METHODS:Heterosexual men and women with Ct infection and their sex partners were enrolled and partner-specific coital and behavioral data collected for the prior 30 days. Microbiological data included Ct culture, and nucleic acid amplification testing (NAAT), quantitative Ct polymerase chain reaction, and ompA genotyping. We measured Ct concordance in dyads and factors (correlates) associated with concordance. RESULTS:One hundred twenty-one women and 125 men formed 128 dyads. Overall, 72.9% of male partners of NAAT-positive women and 68.6% of female partners of NAAT-positive men were Ct-infected. Concordance was more common in dyads with culture-positive members (78.6% of male partners, 77% of female partners). Partners of women and men who were NAAT-positive only had lower concordance (33.3%, 46.4%, respectively). Women in concordant dyads had significantly higher median endocervical quantitative Ct polymerase chain reaction values (3,032) compared with CT-infected women in discordant dyads (1013 inclusion forming units DNA equivalents per mL; P < 0.01). Among 54 Ct-concordant dyads with ompA genotype data for both members, 96.2% had identical genotypes. CONCLUSIONS:Higher organism load appears associated with concordance among women. Same-genotype chlamydial concordance was high in sexual partnerships. No behavioral factors were sufficiently discriminating to guide partner services activities. Findings may help model coitus-specific transmission probabilities.
Project description:The advent of high-throughput technologies, such as 16s rDNA sequencing, has significantly contributed to expanding our knowledge of the microbiota composition of the genital tract during infections such as Chlamydia trachomatis. The growing body of metagenomic data can be further exploited to provide a functional characterization of microbial communities via several powerful computational approaches. Therefore, in this study, we investigated the predicted metabolic pathways of the cervicovaginal microbiota associated with C. trachomatis genital infection in relation to the different Community State Types (CSTs), via PICRUSt2 analysis. Our results showed a more rich and diverse mix of predicted metabolic pathways in women with a CST-IV microbiota as compared to all the other CSTs, independently from infection status. C. trachomatis genital infection further modified the metabolic profiles in women with a CST-IV microbiota and was characterized by increased prevalence of the pathways for the biosynthesis of precursor metabolites and energy, biogenic amino-acids, nucleotides, and tetrahydrofolate. Overall, predicted metabolic pathways might represent the starting point for more precisely designed future metabolomic studies, aiming to investigate the actual metabolic pathways characterizing C. trachomatis genital infection in the cervicovaginal microenvironment.
Project description:Chlamydia trachomatis is an obligate intracellular Gram-negative bacterium that frequently causes an asymptomatic genital tract infection, gradually cleared by host immunity Transcriptome profiles were made of endometrial tissue from women with or without genital tract C. trachomatis infection, to characterize host responses to infection. Profiles showed that infection polarized host defense toward Type 2 immune responses. Responses included fibrin deposition, enhanced wound repair, and tissue remodeling. Trans-cervical endometrial biopsy specimens were collected from 10 women with no identified upper or lower genital tract infection and 12 women with C. trachomatis endometrial infection.
Project description:Chlamydia trachomatis is an obligate intracellular Gram-negative bacterium that frequently causes an asymptomatic genital tract infection, gradually cleared by host immunity Transcriptome profiles were made of endometrial tissue from women with or without genital tract C. trachomatis infection, to characterize host responses to infection. Profiles showed that infection polarized host defense toward Type 2 immune responses. Responses included fibrin deposition, enhanced wound repair, and tissue remodeling.
Project description:BackgroundEstimating prevalence of Chlamydia trachomatis (CT) worldwide is necessary in designing control programs and allocating health resources. We performed a meta-analysis to calculate the prevalence of CT in the general population.MethodsThe Pubmed and Embase databases were searched for eligible population-based studies from its inception through June 5, 2019. Q test and I2 statistic were used to calculate the heterogeneity between studies. Random effects models were used to pool the prevalence of CT. Meta regression was performed to explore the possible sources of heterogeneity. Publication bias was evaluated using a funnel plot and "trim and fill" method.ResultsTwenty nine studies that reported prevalence of CT infection from 24 countries were identified, including a total population of 89,886 persons. The pooled prevalence of CT among the general population was 2.9% (95% CI, 2.4-3.5%), and females had a higher CT prevalence (3.1, 95% CI, 2.5-3.8%) than males (2.6, 95% CI, 2.0-3.2%) (χ2 = 10.38, P < 0.01). Prevalence of CT was highest in region of America (4.5, 95% CI, 3.1-5.9%), especially in Latin America (6.7, 95% CI, 5.0-8.4%), followed by females in region of Africa (3.8, 95% CI, 0.7-6.9%), while South-East Asia had a lowest CT prevalence 0.8% (95% CI, 0.3-1.3%).ConclusionsThis study provided the updated prevalence of CT among general population worldwide. General population from Latin America, especially females, and women in Africa should be given priority by WHO when design and delivery CT control programs.
Project description:BACKGROUND:Repeated Chlamydia trachomatis infections are common among young sexually active women. The relative frequency of reinfection and antibiotic treatment failure is undefined. METHODS:Adolescent women enrolled in a longitudinal cohort had behavioral and sexually transmitted infection assessments performed every 3 months, including amplification tests for C. trachomatis, ompA genotyping, and interviews and diary entries to document sex partner-specific coitus and event-specific condom use. Repeated infections were classified as reinfection or treatment failure by use of an algorithm. All infections for which treatment outcomes were known were used to estimate the effectiveness of antibiotic use. RESULTS:We observed 478 episodes of infection among 210 study participants; 176 women remained uninfected. The incidence rate was 34 episodes/100 woman-years. Of the women who were infected, 121 experienced 1 repeated infections, forming 268 episode pairs; 183 pairs had complete data available and were classified using the algorithm. Of the repeated infections, 84.2% were definite, probable, or possible reinfections; 13.7% were probable or possible treatment failures; and 2.2% persisted without documented treatment. For 318 evaluable infections, we estimated 92.2% effectiveness of antibiotic use. CONCLUSIONS:Most repeated chlamydial infections in this high-incidence cohort were reinfections, but repeated infections resulting from treatment failures occurred as well. Our results have implications for male screening and partner notification programs and suggest the need for improved antibiotic therapies.
Project description:The prevalence and heterogeneity of Chlamydia trachomatis infections in a cohort of female sex workers in Dakar (Senegal) were determined by using endocervical-swab-based PCR DNA amplification assays. The overall prevalence of cervical chlamydial infection was 28.5% (206 of 722), and most of these infections were asymptomatic. An increased number of sexual partners was significantly associated with infection (adjusted odds ratio [AOR] = 1.37; 95% confidence interval [CI] = 1.06 to 1.77), while the presence of a yeast infection was negatively associated with chlamydial infection (AOR = 0.28; 95% CI = 0.10 to 0.83). Six different C. trachomatis genotypes were identified based on phylogenetic analysis of the omp1 gene sequences. Interestingly, genotype E predominated (47.6%) and was not associated with visible signs of cervical inflammation compared to non-E genotypes (P < 0.05). Overall, the high rate of asymptomatic C. trachomatis infection by genotype E may suggest genotype-specific properties that confer a transmission advantage in this high risk population.
Project description:BackgroundChlamydia trachomatis (chlamydia) is the most diagnosed sexually transmitted infection in Belgium. Screening programs focus on young women, due to the implications of chronic asymptomatic infections for reproductive health. Thereby, the frequency of infections in men and older adults is underestimated. This study aimed to estimate the point-prevalence of chlamydia in the broader Belgian population, to inform evidence-based prevention and control strategies.MethodsWe conducted two cross-sectional prevalence studies of chlamydia infection in the population of Belgium aged 16-59 years, 2018-2020. In the CT1 study 12,000 representative individuals were randomly selected from the national register and invited by letter to collect a urine sample at home. The CT2 study used urine samples collected through the Belgian Health Examination Survey. Molecular detection of chlamydia DNA was performed using Xpert® or Abbott Real-Time CT/NG assays. Weighted estimated prevalence and 95% confidence interval (CI) was calculated per gender and age groups of 16/18-29, 30-44 and 45-59 years, relative to the general Belgian population. Data collected on sociodemographic variables and sexual behavior were used to identify potential risk factors for chlamydia infection through calculation of the odds ratio (OR).ResultsThe population-wide weighted estimated prevalence was 1.54% (95% CI 0.78-3) in CT1 and 1.76% (95% CI 0.63-4) in CT2. We observed no statistically significant difference between men and women or age groups. Civil relationship status (OR = 14.1 (95% CI 1.78-112), p < 0.01), sexual intercourse with a casual partner (OR = 6.31 (95% CI 1.66-24.1), p < 0.01) and > 3 sexual partners in the last 12 months (OR = 4.53 (95% CI 1.10-18.6), p = 0.02) were associated with higher relative risk for chlamydia infection.ConclusionNationwide prevalence studies are relevant to assess the distribution of chlamydia and inform public health actions. The overall low prevalence and heterogeneous distribution of chlamydia in the general Belgian population needs to be considered for future strategies and potential harm of testing and treating asymptomatic individuals need to be taken into account. Effective case management should include appropriate treatment of symptomatic patients and partner notification, and prevention strategies should encourage behaviors such as condom use.
Project description:To identify immunodominant antigens that elicit a humoral immune response following a primary and a secondary genital infection, rhesus monkeys were inoculated cervically with Chlamydia trachomatis serovar D. Serum samples were collected and probed with a protein microarray expressing 864/894 (96.4%) of the open reading frames of the C. trachomatis serovar D genome. The antibody response to the primary infection was analyzed in 72 serum samples from 12 inoculated monkeys. The following criteria were utilized to identify immunodominant antigens: proteins found to be recognized by at least 75% (9/12) of the infected monkeys with at least 15% elevations in signal intensity from week 0 to week 8 post infection. All infected monkeys developed Chlamydia specific serum antibodies. Eight proteins satisfied the selection criteria for immunodominant antigens: CT242 (OmpH-like protein), CT541 (mip), CT681 (ompA), CT381 (artJ), CT443 (omcB), CT119 (incA), CT486 (fliY), and CT110 (groEL). Of these, three antigens, CT119, CT486 and CT381, were not previously identified as immunodominant antigens using non-human primate sera. Following the secondary infection, the antibody responses to the eight immunodominant antigens were analyzed and found to be quite different in intensity and duration to the primary infection. In conclusion, these eight immunodominant antigens can now be tested for their ability to identify individuals with a primary C. trachomatis genital infection and to design vaccine strategies to protect against a primary infection with this pathogen.
Project description:Chlamydia trachomatis genital infection continues to be an important public health problem worldwide due to its increasing incidence. C. trachomatis infection can lead to severe sequelae, such as pelvic inflammatory disease, obstructive infertility, and preterm birth. Recently, it has been suggested that the cervico-vaginal microbiota may be an important defense factor toward C. trachomatis infection as well as the development of chronic sequelae. Therefore, the investigation of microbial profiles associated to chlamydial infection is of the utmost importance. Here we present a pilot study aiming to characterize, through the metagenomic analysis of sequenced 16s rRNA gene amplicons, the cervical microbiota from reproductive age women positive to C. trachomatis infection. The main finding of our study showed a marked increase in bacterial diversity in asymptomatic C. trachomatis positive women as compared to healthy controls in terms of Shannon's diversity and Shannon's evenness (P = 0.031 and P = 0.026, respectively). More importantly, the cervical microbiota from C. trachomatis positive women and from healthy controls significantly separated into two clusters in the weighted UniFrac analysis (P = 0.0027), suggesting that differences between the two groups depended entirely on the relative abundance of bacterial taxa rather than on the types of bacterial taxa present. Furthermore, C. trachomatis positive women showed an overall decrease in Lactobacillus spp. and an increase in anaerobes. These findings are part of an ongoing larger epidemiological study that will evaluate the potential role of distinct bacterial communities of the cervical microbiota in C. trachomatis infection.