scholarly journals Antibody Testing in Estimating Past Exposure to Chlamydia trachomatis in the Netherlands Chlamydia Cohort Study

2019 ◽  
Vol 7 (10) ◽  
pp. 442 ◽  
Author(s):  
Hoenderboom ◽  
van Willige ◽  
Land ◽  
Pleijster ◽  
Götz ◽  
...  
Keyword(s):  
Cohort Study ◽  
Chlamydia Trachomatis ◽  
The Netherlands ◽  
Predictive Factors ◽  
Self Report ◽  
Nucleic Acid Amplification ◽  
Lifetime Prevalence ◽  
Multiple Infections ◽  
Antibody Testing ◽  
Antibody Positivity

The asymptomatic course of Chlamydia trachomatis (CT) infections can result in underestimated CT lifetime prevalence. Antibody testing might improve this estimate. We assessed CT antibody positivity and predictive factors thereof in the Netherlands Chlamydia Cohort Study. Women who had ≥1 CT Nucleic Acid Amplification Test (NAAT) in the study (2008–2011) and who provided self-reported information on NAATs were tested for CT major outer membrane protein specific IgG in serum (2016). CT antibody positivity was assessed and predictive factors were identified using multivariable logistic regressions, separately for CT-positive women (≥1 positive NAAT or ≥1 self-reported positive CT test) and CT-negative women (negative by study NAAT and self-report). Of the 3,613 women studied, 833 (23.1%) were CT -positive. Among the CT-negative women, 208 (7.5%, 95%CI 6.5–8.5) tested positive for CT antibodies. This increased CT lifetime prevalence with 5.8% (95%CI 5.0–6.5). Among women with a CT-positive history, 338 (40.6%, 95%CI 38.5–44.1) tested positive. Predictive factors for antibody positivity related to lower social economic status, sexual risk behavior, multiple infections, higher body mass index, and non-smoking. CT antibody testing significantly increased the lifetime prevalence. Combining NAAT outcomes, self-reported positive tests, and antibody testing reduced misclassification in CT prevalence estimates.

scholarly journals Seroprevalence of SARS-CoV-2 antibodies in children - A prospective multicentre cohort study.

2020 ◽  
Author(s):  
Thomas Waterfield ◽  
Chris Watson ◽  
Rebecca Moore ◽  
Kathryn Ferris ◽  
Claire Tonry ◽  
...  
Keyword(s):  
Cohort Study ◽  
Gastrointestinal Symptoms ◽  
Contact Fatigue ◽  
Final Analysis ◽  
Molecular Testing ◽  
Antibody Testing ◽  
Sense Of Smell ◽  
Antibody Titres ◽  
Previous Infection ◽  
Antibody Positivity

Background Studies based on molecular testing of oral/nasal swabs underestimate SARS-CoV-2 infection due to issues with test sensitivity and timing of testing. The objective of this study was to report the presence of SARS-CoV-2 antibodies, consistent with previous infection, and to report the symptomatology of infection in children. Design This multicentre observational cohort study, conducted between 16th April - 3rd July 2020 at 5 UK sites, aimed to recruit 900 children aged 2 to 15 years of age. Participants provided blood samples for SARS-CoV-2 antibody testing and data were gathered regarding unwell contacts and symptoms. Results 1007 participants were enrolled, and 992 were included in the final analysis. The median age of participants was 10.1 years. There were 68 (6.9%) participants with positive SARS-CoV-2 antibody tests indicative of previous SARS-CoV-2 infection. Of these, 34/68 (50%) reported no symptoms. The presence of antibodies and the mean antibody titre was not influenced by age. Following multivariate analysis 4 independent variables were identified as significantly associated with SARS-CoV-2 infection. These were: known infected household contact; fatigue; gastrointestinal symptoms; and changes in sense of smell or taste. Discussion In this study children demonstrated similar antibody titres in response to SARS-CoV-2 irrespective of age. The symptoms of SARS-CoV-2 infection in children were subtle but of those reported, fatigue, gastrointestinal symptoms and changes in sense of smell or taste were most strongly associated with antibody positivity. Registration This study was registered at https://www.clinicaltrials.gov (trial registration: NCT04347408) on the 15/04/2020.

scholarly journals Screening for Chlamydia trachomatis and Neisseria gonorrhoeae infection among asymptomatic men who have sex with men in Bangkok, Thailand

2017 ◽  
Vol 29 (6) ◽  
pp. 577-587 ◽  
Author(s):  
Sarika Pattanasin ◽  
Eileen F Dunne ◽  
Punneeporn Wasinrapee ◽  
Jaray Tongtoyai ◽  
Wannee Chonwattana ◽  
...  
Keyword(s):  
Cohort Study ◽  
Nucleic Acid ◽  
Chlamydia Trachomatis ◽  
Neisseria Gonorrhoeae ◽  
Nucleic Acid Amplification ◽  
Anatomic Site ◽  
Number Needed To Screen ◽  
Sex With Men ◽  
Study Participants ◽  
Asymptomatic Men

We report positivity rates of Chlamydia trachomatis (CT) and Neisseria gonorrhoeae (NG) infection at each anatomic site among asymptomatic men who have sex with men (MSM). We calculated the number needed to screen (NNS) to detect CT and NG infection at each anatomic site. From 2006 to 2010, we enrolled Thai MSM, age ≥ 18 years into the Bangkok MSM Cohort Study. Participants underwent physical examination and had rectal, urethral, and pharyngeal screening for CT and NG infection using nucleic acid amplification tests (NAATs). Of 1744 enrollees, 1696 (97.2%) had no symptoms of CT and NG infection. The positivity rates of CT and NG infection at any site were 14.3% (rectum, urethra, pharynx) and 6.4% (rectum, urethra), respectively. The NNS to detect rectal CT and rectal NG infections was 10 and 16, respectively (p < 0.05). For urethral infection, the NNS of CT was lower than the NNS of NG (22, 121: p < 0.05). The lowest NNS found for rectal CT infection was in HIV-infected MSM (6, 5–8). Asymptomatic CT and NG infection were common among MSM in Bangkok, Thailand and frequently detected in the rectum. In setting where screening in all specimens using NAAT is not feasible, rectal screening should be a priority.

scholarly journals The Netherlands Chlamydia cohort study (NECCST) protocol to assess the risk of late complications following Chlamydia trachomatis infection in women

2017 ◽  
Vol 17 (1) ◽  
Author(s):  
B. M. Hoenderboom ◽  
A. A. M. van Oeffelen ◽  
B. H. B. van Benthem ◽  
J. E. A. M. van Bergen ◽  
N. H. T. M. Dukers-Muijrers ◽  
...  
Keyword(s):  
Cohort Study ◽  
Chlamydia Trachomatis ◽  
The Netherlands ◽  
Late Complications ◽  
Chlamydia Trachomatis Infection

scholarly journals Cohort profile: LIFEWORK, a prospective cohort study on occupational and environmental risk factors and health in the Netherlands

BMJ Open ◽  
2018 ◽  
Vol 8 (2) ◽  
pp. e018504 ◽  
Author(s):  
Marije Reedijk ◽  
Virissa Lenters ◽  
Pauline Slottje ◽  
Anouk Pijpe ◽  
Petra H Peeters ◽  
...  
Keyword(s):  
Cohort Study ◽  
The Netherlands ◽  
Mobile Phone ◽  
Prospective Cohort ◽  
Weighted Kappa ◽  
Cancer Registries ◽  
Self Report ◽  
Base Stations ◽  
Mobile Phone Use

PurposeLIFEWORK is a large federated prospective cohort established in the Netherlands to quantify the health effects of occupational and environmental exposures. This cohort is also the Dutch contribution to the international Cohort Study of Mobile Phone Use and Health (COSMOS). In this paper, we describe the study design, ongoing data collection, baseline characteristics of participants and the repeatability of key questionnaire items.Participants88 466 participants were enrolled in three cohort studies in 2011–2012. Exposure information was collected by a harmonised core questionnaire, or modelled based on occupational and residential histories; domains include air pollution (eg, nitrogen dioxide (NO2), particulate matter with diameter ≤2.5 µm (PM2.5)), noise, electromagnetic fields (EMF), mobile phone use, shift work and occupational chemical exposures. Chronic and subacute health outcomes are assessed by self-report and through linkage with health registries.Findings to dateParticipants had a median age of 51 years at baseline (range 19–87), and the majority are female (90%), with nurses being over-represented. Median exposure levels of NO2, PM2.5, EMF from base stations and noise at the participants’ home addresses at baseline were 22.9 µg/m3, 16.6 µg/m3, 0.003 mWm2and 53.1 dB, respectively. Twenty-two per cent of participants reported to have started using a mobile phone more than 10 years prior to baseline. Repeatability for self-reported exposures was moderate to high (weighted kappa range: 0.69–1) for a subset of participants (n=237) who completed the questionnaire twice.Future plansWe are actively and passively observing participants; we plan to administer a follow-up questionnaire every 4–5 years—the first follow-up will be completed in 2018—and linkage to cause-of-death and cancer registries occurs on a (bi)annual basis. This prospective cohort offers a unique, large and rich resource for research on contemporary occupational and environmental health risks and will contribute to the large international COSMOS study on mobile phone use and health.

scholarly journals Chlamydia trachomatis Whole-Proteome Microarray Analysis of The Netherlands Chlamydia Cohort Study

2019 ◽  
Vol 7 (12) ◽  
pp. 703 ◽  
Author(s):  
Katrin Hufnagel ◽  
Bernice Hoenderboom ◽  
Christoph Harmel ◽  
Juliane K. Rohland ◽  
Birgit H.B. van Benthem ◽  
...  
Keyword(s):  
Cohort Study ◽  
Chlamydia Trachomatis ◽  
The Netherlands ◽  
Ectopic Pregnancy ◽  
Inflammatory Disease ◽  
Chronic Pelvic Pain ◽  
Serum Samples ◽  
Tubal Factor Infertility ◽  
Tubal Factor ◽  
Infection Markers

Chlamydia trachomatis (Ct) whole-proteome microarrays were utilized to identify antibody patterns associated with infection; pelvic inflammatory disease (PID), tubal factor infertility, chronic pelvic pain (CPP) and ectopic pregnancy in a subsample of the Netherlands Chlamydia cohort study. Serum pools were analyzed on whole-proteome arrays. The 121 most reactive antigens identified during whole-proteome arrays were selected for further analysis with minimized microarrays that allowed for single sera analysis. From the 232 single sera; 145 (62.5%) serum samples were reactive for at least one antigen. To discriminate between positive and negative serum samples; we created a panel of in total 18 antigens which identified 96% of all microarray positive samples. Antigens CT_858; CT_813 and CT_142 were most reactive. Comparison of antibody reactivity’s among women with and without Ct related sequelae revealed that the reactivity of CT_813 and CT_142 was less common among women with PID compared to women without (29.0% versus 58.6%, p = 0.005 and 25.8% versus 50.6%, p = 0.017 respectively). CT_858 was less common among CPP cases compared to controls (33.3% versus 58.6; p = 0.028). Using a whole-proteome array to select antigens for minimized arrays allows for the identification of novel informative antigens as general infection markers or disease associated antigens

scholarly journals Seroprevalence of SARS-CoV-2 antibodies in children: a prospective multicentre cohort study

2020 ◽  
pp. archdischild-2020-320558 ◽  
Author(s):  
Thomas Waterfield ◽  
Chris Watson ◽  
Rebecca Moore ◽  
Kathryn Ferris ◽  
Claire Tonry ◽  
...  
Keyword(s):  
Cohort Study ◽  
Multivariable Analysis ◽  
Gastrointestinal Symptoms ◽  
Final Analysis ◽  
Molecular Testing ◽  
Antibody Testing ◽  
Sense Of Smell ◽  
Antibody Titres ◽  
Previous Infection ◽  
Antibody Positivity

BackgroundStudies based on molecular testing of oral/nasal swabs underestimate SARS-CoV-2 infection due to issues with test sensitivity, test timing and selection bias. The objective of this study was to report the presence of SARS-CoV-2 antibodies, consistent with previous infection.DesignThis multicentre observational cohort study, conducted between 16 April to 3 July 2020 at 5 UK sites, recruited children of healthcare workers, aged 2–15 years. Participants provided blood samples for SARS-CoV-2 antibody testing and data were gathered regarding unwell contacts and symptoms.Results1007 participants were enrolled, and 992 were included in the final analysis. The median age of participants was 10·1 years. There were 68 (6.9%) participants with positive SARS-CoV-2 antibody tests indicative of previous SARS-CoV-2 infection. Of these, 34/68 (50%) reported no symptoms prior to testing. The presence of antibodies and the mean antibody titre was not influenced by age. Following multivariable analysis four independent variables were identified as significantly associated with SARS-CoV-2 seropositivity: known infected household contact OR=10.9 (95% CI 6.1 to 19.6); fatigue OR=16.8 (95% CI 5.5 to 51.9); gastrointestinal symptoms OR=6.6 (95% CI 3.0 to 13.8); and changes in sense of smell or taste OR=10.0 (95% CI 2.4 to 11.4).DiscussionChildren demonstrated similar antibody titres in response to SARS-CoV-2 irrespective of age. Fatigue, gastrointestinal symptoms and changes in sense of smell or taste were the symptoms most strongly associated with SARS-CoV-2 antibody positivity.Trial registration numberNCT0434740.

scholarly journals O04.4 The netherlands chlamydia cohort study (NECCST): risks of long-term complications following chlamydia trachomatis infections in women

2017 ◽  
Author(s):  
Hoenderboom Bm ◽  
Van Benthem Bhb ◽  
Van Oeffelen Aam ◽  
Van Bergen Jeam ◽  
Morré Sa ◽  
...  
Keyword(s):  
Cohort Study ◽  
Chlamydia Trachomatis ◽  
The Netherlands
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