Chlamydia trachomatis Infection in minority adolescent women: a public health challenge

A large-scale machine learning study of sociodemographic factors contributing to COVID-19 severity

Understanding sociodemographic factors behind COVID-19 severity relates to significant methodological difficulties, such as differences in testing policies and epidemics phase, as well as a large number of predictors that can potentially contribute to severity. To account for these difficulties, we assemble 115 predictors for more than 3,000 US counties and employ a well-defined COVID-19 severity measure derived from epidemiological dynamics modeling. We then use a number of advanced feature selection techniques from machine learning to determine which of these predictors significantly impact the disease severity. We obtain a surprisingly simple result, where only two variables are clearly and robustly selected-population density and proportion of African Americans. Possible causes behind this result are discussed. We argue that the approach may be useful whenever significant determinants of disease progression over diverse geographic regions should be selected from a large number of potentially important factors.

Nanoparticle-Based Lateral Flow Biosensor Integrated With Loop-Mediated Isothermal Amplification for Rapid and Visual Identification of Chlamydia trachomatis for Point-of-Care Use

Chlamydial infection, caused by Chlamydia trachomatis, is the most common bacterial sexually transmitted infection and remains a major public health problem worldwide, particularly in underdeveloped regions. Developing a rapid and sensitive point-of-care (POC) testing for accurate screening of C. trachomatis infection is critical for earlier treatment to prevent transmission. In this study, a novel diagnostic assay, loop-mediated isothermal amplification integrated with gold nanoparticle-based lateral flow biosensor (LAMP-LFB), was devised and applied for diagnosis of C. trachomatis in clinical samples. A set of LAMP primers based on the ompA gene from 14 C. trachomatis serological variants (serovar A-K, L1, L2, L3) was successfully designed and used for the development of C. trachomatis-LAMP-LFB assay. The optimal reaction system can be performed at a constant temperature of 67°C for 35 min. The total assay process, including genomic DNA extraction (~15 min), LAMP reaction (35 min), and LFB readout (~2 min), could be finished within 60 min. The C. trachomatis-LAMP-LFB could detect down to 50 copies/ml, and the specificity was 100%, no cross-reactions with other pathogens were observed. Hence, our C. trachomatis-LAMP-LFB was a rapid, reliable, sensitive, cost-effective, and easy-to-operate assay, which could offer an attractive POC testing tool for chlamydial infection screening, especially in resource starvation settings.

Electronic Health Record Reminders for Chlamydia Screening in an American Indian Population

OBJECTIVES

Indian Health Service (IHS) screening rates for Chlamydia trachomatis are lower than national rates of chlamydia screening in the Southwest. We describe and evaluate the effect of a public health intervention consisting of electronic health record (EHR) reminders to alert health care providers to screen for chlamydia at an IHS facility. We also conducted an awareness presentation among health care providers on chlamydia screening.

METHODS

We conducted our intervention from November 1, 2013, through October 31, 2015, at an IHS facility in the Southwest. We implemented algorithms that queried database values to assess chlamydia screening performance in 6 clinical departments. We presented data on the screening performance of clinical departments and health care providers (de-identified) in the awareness presentations. We re-queried database values 1 and 2 years after implementation of the EHR reminder intervention to evaluate before-and-after screening rates, comparing data among all patients and among female patients only.

RESULTS

We found small, sustained relative increases in chlamydia screening rates during the 2012-2015 evaluation period: 20.8% pre-intervention to 24.9% and 24.2% one and two years postintervention, respectively, across all patients; 32.3% preintervention to 36.6% and 35.6% one and two years postintervention, respectively, among female patients. Increases in clinical department-specific screening rates varied and were most prominent in internal medicine (35.8% preintervention to peak 65.8% postintervention). The 1 clinic (obstetrics-gynecology) that did not receive an awareness presentation showed a consistent downward trend in screening rates, although absolute rates were consistently higher in that clinic than in other clinics.

CONCLUSIONS

Awareness presentations that offer feedback to health care providers on screening performance, heighten provider awareness of the importance of chlamydia screening, and promote development of novel provider-initiated screening protocols may help to increase screening rates when combined with EHR reminders.

Prevalence of Chlamydia trachomatis in an asymptomatic female population attending cervical cytology services of three healthcare centers in Medellín, Colombia

Introducción.

La infección de transmisión sexual causada por Chlamydia trachomatis es la más frecuente de etiología bacteriana en el mundo. Aunque puede ser asintomática en la mayoría de los casos, C. trachomatis puede generar diversos problemas de salud reproductiva en mujeres, como cervicitis, endometritis y salpingitis. A pesar de su importancia, en Medellín no se cuenta con suficientes datos epidemiológicos sobre esta infección.

Objetivo.

Determinar la prevalencia de C. trachomatis en mujeres de Medellín, determinar los posibles factores de riesgo y evaluar la relación con la infección por el virus de papiloma humano (HPV).

Materiales y métodos.

Se hizo un estudio transversal multicéntrico para detectar la infección por C. trachomatis en 1.282 mujeres mediante reacción en cadena de la polimerasa (PCR) convencional y el estuche comercial LightMix 480 HT CT/NG™ (Roche, Basilea, Suiza).

Resultados.

La prevalencia total de la infección por C. trachomatis fue de 4,1 % (IC_95% 2,9-5,3). Se encontró una relación significativa de la infección con la edad, el consumo de cigarrillo y el uso de anticonceptivos hormonales.

Conclusión.

La prevalencia de la infección es similar a la reportada en otros lugares del país y del mundo, siendo las mujeres más jóvenes las más afectadas. En cuanto a la presentación del HPV, no se encontró ningún tipo de relación con C. trachomatis.

Action Needed on Chlamydia Vaccines

Chlamydia trachomatis is the most common infectious disease in the USA for which the Centers for Disease Control (CDC) collects case reports. Its prevalence in young women is a public health crisis given the threat to their reproductive health. Consequently, development of a vaccine to prevent infection should be prioritized.

Amoebal endosymbiont Parachlamydia acanthamoebae Bn9 can grow in immortal human epithelial HEp-2 cells at low temperature; an in vitro model system to study chlamydial evolution

Ancient chlamydiae diverged into pathogenic and environmental chlamydiae 0.7–1.4 billion years ago. However, how pathogenic chlamydiae adapted to mammalian cells that provide a stable niche at approximately 37°C, remains unknown, although environmental chlamydiae have evolved as endosymbionts of lower eukaryotes in harsh niches of relatively low temperatures. Hence, we assessed whether an environmental chlamydia, Parachlamydia Bn₉, could grow in human HEp-2 cells at a low culture temperature of 30°C. The assessment of inclusion formation by quantitative RT-PCR revealed that the numbers of bacterial inclusion bodies and the transcription level of 16SrRNA significantly increased after culture at 30°C compared to at 37°C. Confocal microscopy showed that the bacteria were located close to HEp-2 nuclei and were actively replicative. Transmission electron microscopy also revealed replicating bacteria consisting of reticular bodies, but with a few elementary bodies. Cytochalasin D and rifampicin inhibited inclusion formation. Lactacystin slightly inhibited bacterial inclusion formation. KEGG analysis using a draft genome sequence of the bacteria revealed that it possesses metabolic pathways almost identical to those of pathogenic chlamydia. Interestingly, comparative genomic analysis with pathogenic chlamydia revealed that the Parachlamydia similarly possess the genes encoding Type III secretion system, but lacking genes encoding inclusion membrane proteins (IncA to G) required for inclusion maturation. Taken together, we conclude that ancient chlamydiae had the potential to grow in human cells, but overcoming the thermal gap was a critical event for chlamydial adaptation to human cells.

HPV and Chlamydia trachomatis co-detection in young asymptomatic women from high incidence area for cervical cancer

Chlamydia trachomatis causing chronic inflammatory diseases has investigated as possible human papillomavirus (HPV) cofactor in cervical cancer. The aim of this study is to evaluate the prevalence of Chlamydia trachomatis and HPV co-infection in different cohorts of asymptomatic women from a Northern Italy area at high incidence for cervical cancer. Cervical samples from 441 females were collected from Cervical Cancer Screening Program, Sexually Transmitted Infectious and Assisted Reproductive Technology centres. HPV and Chlamydia trachomatis were detected simultaneously and genotyped using a highly sensitive bead based assay. The overall prevalence of Chlamydia trachomatis was estimated 9.7%, in contrast with the reported national data of 2.3%, and co-infection with HPV was diagnosed in the 17% of the samples. In females ≤ 25 years of age, the infection reached a peak of 22% and co-infection with HPV of 45.8% (P < 0.001). Of note, in young females diagnosed with low grade cervical lesions, no significant difference between Chlamydia trachomatis and HPV distribution was observed, while differently, HPV co-infection was found significantly associated to the presence of intraepithelial lesions when compared to older females (20% vs. 1%; P < 0.001). In this study, the use of a high sensitive molecular technique exhibited higher analytical sensitivity than the referred assays for the diagnosis of Chlamydia trachomatis and HPV co-infection in asymptomatic females, leading to reduction of the potential to identify incorrectly the infection status. An active screening for timely treatment of Chlamydia trachomatis infection is suggested in young females to evaluate a possible decrease in incidence of pre-cancer intraepithelial lesions.

High-temperature adapted primitive Protochlamydia found in Acanthamoeba isolated from a hot spring can grow in immortalized human epithelial HEp-2 cells

To elucidate how ancient pathogenic chlamydiae could overcome temperature barriers to adapt to human cells, we characterized a primitive chlamydia found in HS-T3 amoebae (Acanthamoeba) isolated from a hot spring. Phylogenetic analysis revealed the primitive species to be Protochlamydia. In situ hybridization staining showed broad distribution into the amoebal cytoplasm, which was supported by transmission electron microscopic analysis showing typical chlamydial features, with inclusion bodies including both elementary and reticular bodies. Interestingly, although most amoebae isolated from natural environments show reduced growth at 37°C, the HS-T3 amoebae harbouring the Protochlamydia grew well at body temperature. Although infection with Protochlamydia did not confer temperature tolerance to the C3 amoebae, the number of infectious progenies rapidly increased at 37°C with amoebal lysis. In immortalized human epithelial HEp-2 cells, fluorescence microscopic study revealed atypical inclusion of the Protochlamydia, and quantitative real-time polymerase chain reaction analyses also showed an increase in 16S ribosomal RNA DNA amounts. Together, these results showed that the Protochlamydia found in HS-T3 amoebae isolated from a hot spring successfully adapted to immortalized human HEp-2 cells at 37°C, providing further information on the evolution of ancient Protochlamydia to the present pathogenic chlamydiae.