{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,10,5]],"date-time":"2026-10-05T16:39:46Z","timestamp":1791218386610,"version":"4.1.0"},"reference-count":36,"publisher":"BMJ","issue":"8","content-domain":{"domain":["bmj.com"],"crossmark-restriction":true},"short-container-title":["BMJ Open"],"accepted":{"date-parts":[[2016,7,26]]},"published-print":{"date-parts":[[2016,8]]},"abstract":"<jats:sec>\n                    <jats:title>Background<\/jats:title>\n                    <jats:p>Genital chlamydia infection (chlamydia) is the most commonly reported sexually transmitted infection (STI) in Sweden. To guide prevention needs, we aimed to investigate factors associated with chlamydia.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Methods<\/jats:title>\n                    <jats:p>A cohort of visitors aged 20\u201340\u2005years at an urban STI clinic in Sweden was recruited. Behavioural data were collected using a self-administered questionnaire. Self-sampled specimens were tested for chlamydia by a DNA amplification assay. Statistically significant (p&lt;0.05) and epidemiologically relevant covariates were entered in a multivariate Poisson model adjusted for potential confounders (age and gender). Backward stepwise elimination produced a final model. Multiple imputation was used to account for missing values.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Results<\/jats:title>\n                    <jats:p>Out of 2814 respondents, 1436 were men with a chlamydia positivity rate of 12.6% vs 8.9% in women. Lifetime testing for chlamydia and HIV was high (82% and 60%, respectively). Factors significantly associated with chlamydia were: 20\u201324\u2005years old (adjusted risk ratio (ARR)=2.10, 95% CI 1.21 to 3.65); testing reason: contact with a chlamydia case (ARR=6.55, 95% CI 4.77 to 8.98) and having symptoms (ARR=2.19, 95% CI 1.48 to 3.24); 6\u201310 sexual partners (ARR=1.53, 95% CI 1.06 to 2.21); last sexual activity \u2018vaginal sex and oral sex and anal sex and petting\u2019 (ARR=1.84, 95% CI 1.09 to 3.10); alcohol use before sex (ARR=1.98, 95% CI 1.10 to 3.57); men with symptoms (ARR=2.09, 95% CI 1.38 to 3.18); tested for chlamydia (ARR=0.72, 95% CI 0.55 to 0.94).<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Conclusions<\/jats:title>\n                    <jats:p>Risk factors associated with chlamydia were consistent with previous reports in similar settings and suggest no major changes over time. Increased risk for chlamydia infection associated with high-risk behaviour (eg, alcohol use, increased number of sexual partners) supports the need for behavioural interventions in this population such as promotion of safer sex behaviour (condom use) and testing.<\/jats:p>\n                  <\/jats:sec>","DOI":"10.1136\/bmjopen-2016-011312","type":"journal-article","created":{"date-parts":[[2016,8,26]],"date-time":"2016-08-26T22:49:16Z","timestamp":1472251756000},"page":"e011312","update-policy":"https:\/\/doi.org\/10.1136\/crossmarkpolicy","source":"Crossref","is-referenced-by-count":21,"title":["Sexual and testing behaviour associated with\n                    <i>Chlamydia trachomatis<\/i>\n                    infection: a cohort study in an STI clinic in Sweden"],"prefix":"10.1136","volume":"6","author":[{"given":"Inga","family":"Veli\u010dko","sequence":"first","affiliation":[{"name":"Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, Stockholm, Sweden"},{"name":"Unit of Monitoring and Evaluation, Public Health Agency of Sweden, Stockholm, Sweden"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Alexander","family":"Ploner","sequence":"additional","affiliation":[{"name":"Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, Stockholm, Sweden"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"P\u00e4r","family":"Spar\u00e9n","sequence":"additional","affiliation":[{"name":"Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, Stockholm, Sweden"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Lena","family":"Marions","sequence":"additional","affiliation":[{"name":"Department of Clinical Science and Education, Karolinska Institutet, Stockholm, Sweden"},{"name":"Section of Obstetrics and Gynaecology, Stockholm South General Hospital, Stockholm, Sweden"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Bj\u00f6rn","family":"Herrmann","sequence":"additional","affiliation":[{"name":"Section of Clinical Microbiology, Department of Medical Sciences, Uppsala University, Uppsala, Sweden"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Sharon","family":"K\u00fchlmann-Berenzon","sequence":"additional","affiliation":[{"name":"Unit of Monitoring and Evaluation, Public Health Agency of Sweden, Stockholm, Sweden"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"239","published-online":{"date-parts":[[2016,8,26]]},"reference":[{"key":"2025121401345334000_6.8.e011312.1","unstructured":"Annual Epidemiological Report 2013. Reporting on 2011 surveillance data and 2012 epidemic intelligence data. Stockholm, European Centre for Disease Prevention and Control, 2013."},{"key":"2025121401345334000_6.8.e011312.2","unstructured":"Swedish Institute for Communicable Disease Control (Smittskyddsinstitutet). Epidemiological report 2012. Smittskyddsinstitutet. 2013 [In Swedish]. https:\/\/www.folkhalsomyndigheten.se\/pagefiles\/14963\/epidemiologisk-arsrapport-2012.pdf (accessed Aug 19, 2016)"},{"key":"2025121401345334000_6.8.e011312.3","doi-asserted-by":"publisher","DOI":"10.1095\/biolreprod.108.067835"},{"key":"2025121401345334000_6.8.e011312.4","doi-asserted-by":"publisher","DOI":"10.1086\/652395"},{"key":"2025121401345334000_6.8.e011312.5","unstructured":"The National Board of Health and Welfare of Sweden (Socialstyrelsen). The National Action Plan for Chlamydia Prevention with focus on young people aged 15-29 years. The National Board of Health and Welfare of Sweden, 2009. [In Swedish]. http:\/\/www.lafa.nu\/Documents\/Styrdokument\/Nationell%20handlingsplan%20f%C3%B6r%20klamydiaprevention.pdf (accessed Aug 19, 2016)."},{"key":"2025121401345334000_6.8.e011312.6","doi-asserted-by":"publisher","DOI":"10.1136\/sextrans-2014-051607"},{"key":"2025121401345334000_6.8.e011312.7","doi-asserted-by":"publisher","DOI":"10.1186\/1471-2334-12-150"},{"key":"2025121401345334000_6.8.e011312.8","first-page":"195","article-title":"Risk factors for genital chlamydial infection","volume":"13","author":"Navarro","year":"2002","journal-title":"Can J Infect Dis"},{"key":"2025121401345334000_6.8.e011312.9","doi-asserted-by":"publisher","DOI":"10.1177\/0956462413491732"},{"key":"2025121401345334000_6.8.e011312.10","doi-asserted-by":"publisher","DOI":"10.1016\/S0140-6736(13)61947-9"},{"key":"2025121401345334000_6.8.e011312.11","doi-asserted-by":"publisher","DOI":"10.1097\/01.olq.0000187908.42622.fd"},{"key":"2025121401345334000_6.8.e011312.12","doi-asserted-by":"publisher","DOI":"10.1258\/ijsa.2011.010481"},{"key":"2025121401345334000_6.8.e011312.13","doi-asserted-by":"crossref","first-page":"241","DOI":"10.1097\/00007435-199705000-00001","article-title":"Sexual behavior risk factors associated with bacterial vaginosis and Chlamydia trachomatis infection","volume":"24","author":"Nilsson","year":"1997","journal-title":"Sex Transm Dis"},{"key":"2025121401345334000_6.8.e011312.14","doi-asserted-by":"publisher","DOI":"10.1177\/095646249200300208"},{"key":"2025121401345334000_6.8.e011312.15","doi-asserted-by":"crossref","first-page":"458","DOI":"10.3109\/13625187.2012.729624","article-title":"Risk of self-reported Chlamydia trachomatis infection by social and lifestyle factors: a study based on survey data from young adults in Stockholm, Sweden","volume":"17","author":"Deogan","year":"2012","journal-title":"Eur J Contracept Reprod Health Care"},{"key":"2025121401345334000_6.8.e011312.16","doi-asserted-by":"crossref","first-page":"23","DOI":"10.1016\/j.srhc.2012.11.004","article-title":"Risk factors for Chlamydia trachomatis infection among users of an internet-based testing service in Sweden","volume":"4","author":"Novak","year":"2013","journal-title":"Sex Reprod Healthc"},{"key":"2025121401345334000_6.8.e011312.17","doi-asserted-by":"publisher","DOI":"10.1071\/SH08095"},{"key":"2025121401345334000_6.8.e011312.18","doi-asserted-by":"crossref","first-page":"198","DOI":"10.1186\/1471-2458-9-198","article-title":"Repeat infection with Chlamydia trachomatis: a prospective cohort study from an STI-clinic in Stockholm","volume":"9","author":"Edgardh","year":"2009","journal-title":"BMC Public Health"},{"key":"2025121401345334000_6.8.e011312.19","unstructured":"Tsoumanis A , Velicko I , K\u00fchlmann-Berenzon S . 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