{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,8,4]],"date-time":"2026-08-04T14:53:51Z","timestamp":1785855231545,"version":"3.56.0"},"reference-count":46,"publisher":"Oxford University Press (OUP)","issue":"8","license":[{"start":{"date-parts":[[2026,7,24]],"date-time":"2026-07-24T00:00:00Z","timestamp":1784851200000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/100004319","name":"Pfizer","doi-asserted-by":"publisher","id":[{"id":"10.13039\/100004319","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":[],"published-print":{"date-parts":[[2026,8,1]]},"abstract":"<jats:title>Abstract<\/jats:title>\n                  <jats:sec>\n                    <jats:title>Background<\/jats:title>\n                    <jats:p>The burden of pneumococcal disease in older adults remains high in the postpneumococcal conjugate vaccine (PCV) era. We hypothesized that older adults may represent a carriage reservoir of Streptococcus pneumoniae.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Methods<\/jats:title>\n                    <jats:p>Paired naso- and oropharyngeal (NP and OP) swabs and questionnaires were collected during 2019\u20132022 from adults \u226565 years of age. Pneumococcal carriage and serotype distribution were determined by phenotypical and molecular methods.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Results<\/jats:title>\n                    <jats:p>A total of 172\/1764 participants (9.8% [95% confidence interval {CI} 8.4\u201311.2]) were positive for carriage of S. pneumoniae by either culture (0.3%) or lytA\/piaB DNA in NP (2.0%) or OP (8.4%) samples. Overall, 118 serogroup- or serotype-specific carriage events were identified by multiplex polymerase chain reaction across 16 distinct serospecificities in 93 samples, while 79 samples were nontypeable. PCV13 types accounted for 8.0%, nonvaccine types for 11.0% and polysaccharide pneumococcal vaccine 23 (PPV23)\/non-PCV13 types for 81.0%. All carriage serotypes, except serotype 2, had been identified in invasive pneumococcal disease (IPD) isolates among adults \u226565 years during 2019\u20132022. Having young grandchildren was associated with increased odds of carriage (adjusted odds ratio [OR] 1.8, 95% CI 1.2\u20132.5, P = .0031). No association between PPV23 immunization and carriage was observed (OR 0.8, 95% CI .5\u20131.3).<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Conclusions<\/jats:title>\n                    <jats:p>Older adults were carriers of a wide range of IPD-causing serotypes. Both carriage and IPD serotypes were mainly comprised of non-PCV13 serotypes. Immunization with higher valency conjugated vaccines is likely required to reduce residual pneumococcal disease among older adults.<\/jats:p>\n                  <\/jats:sec>","DOI":"10.1093\/ofid\/ofag452","type":"journal-article","created":{"date-parts":[[2026,7,22]],"date-time":"2026-07-22T11:57:32Z","timestamp":1784721452000},"source":"Crossref","is-referenced-by-count":0,"title":["Prevalence, Serotype Distribution, and Risk Factors Associated With\n                    <i>Streptococcus pneumoniae<\/i>\n                    Carriage in Older Adults in Denmark, 2019\u20132022"],"prefix":"10.1093","volume":"13","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-8078-8867","authenticated-orcid":false,"given":"Michaela","family":"Tinggaard","sequence":"first","affiliation":[{"name":"Department of Infectious Diseases, Copenhagen University Hospital\u2014Amager and Hvidovre , Hvidovre ,","place":["Denmark"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-7294-4911","authenticated-orcid":false,"given":"Hans-Christian","family":"Slotved","sequence":"additional","affiliation":[{"name":"Department of Bacteria, Parasites and Fungi, Statens Serum Institut , Copenhagen ,","place":["Denmark"]},{"name":"Department of Natural and Environmental Science, Roskilde University , Roskilde ,","place":["Denmark"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-1678-6605","authenticated-orcid":false,"given":"Randi F\u00f8ns","family":"Petersen","sequence":"additional","affiliation":[{"name":"Department of Bacteria, Parasites and Fungi, Statens Serum Institut , Copenhagen ,","place":["Denmark"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Nichlas","family":"Hovmand","sequence":"additional","affiliation":[{"name":"Department of Infectious Diseases, Copenhagen University Hospital\u2014Amager and Hvidovre , Hvidovre ,","place":["Denmark"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-0698-9385","authenticated-orcid":false,"given":"Thomas","family":"Benfield","sequence":"additional","affiliation":[{"name":"Department of Infectious Diseases, Copenhagen University Hospital\u2014Amager and Hvidovre , Hvidovre ,","place":["Denmark"]},{"name":"Department of Clinical Medicine, Faculty of Health and Medical Sciences, University of Copenhagen , Copenhagen ,","place":["Denmark"]}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"286","published-online":{"date-parts":[[2026,7,24]]},"reference":[{"key":"2026080410183612800_ofag452-B1","doi-asserted-by":"crossref","first-page":"e0017524","DOI":"10.1128\/cmr.00175-24","article-title":"Update on the evolving landscape of pneumococcal capsule types: new discoveries and way forward","volume":"38","author":"Ganaie","year":"2025","journal-title":"Clin Microbiol Rev"},{"key":"2026080410183612800_ofag452-B2","first-page":"001483","article-title":"SeroBA(v2.0) and SeroBAnk: a robust genome-based serotyping scheme and comprehensive atlas of capsular diversity in Streptococcus pneumoniae","volume":"11","author":"Lorenz","year":"2025","journal-title":"Microb Genom"},{"key":"2026080410183612800_ofag452-B3","doi-asserted-by":"crossref","first-page":"e1000476","DOI":"10.1371\/journal.ppat.1000476","article-title":"Pneumococcal capsular polysaccharide structure predicts serotype prevalence","volume":"5","author":"Weinberger","year":"2009","journal-title":"PLoS Pathog"},{"key":"2026080410183612800_ofag452-B4","doi-asserted-by":"crossref","first-page":"e0177113","DOI":"10.1371\/journal.pone.0177113","article-title":"Serotype distribution of Streptococcus pneumoniae causing invasive disease in children in the post-PCV era: a systematic review and meta-analysis","volume":"12","author":"Balsells","year":"2017","journal-title":"PLoS One"},{"key":"2026080410183612800_ofag452-B5","doi-asserted-by":"crossref","first-page":"841","DOI":"10.1586\/erv.12.53","article-title":"The fundamental link between pneumococcal carriage and disease","volume":"11","author":"Simell","year":"2012","journal-title":"Expert Rev Vaccines"},{"key":"2026080410183612800_ofag452-B6","doi-asserted-by":"crossref","first-page":"1066","DOI":"10.1093\/cid\/ciu524","article-title":"Impact of 13-valent pneumococcal conjugate vaccination in invasive pneumococcal disease incidence and mortality","volume":"59","author":"Harboe","year":"2014","journal-title":"Clin Infect Dis"},{"key":"2026080410183612800_ofag452-B7","author":"Statens Serum Institute"},{"key":"2026080410183612800_ofag452-B8","doi-asserted-by":"crossref","first-page":"137","DOI":"10.3201\/eid2801.210734","article-title":"Serotype replacement after Introduction of 10-valent and 13-valent pneumococcal conjugate vaccines in 10 countries, Europe","volume":"28","author":"Hanquet","year":"2022","journal-title":"Emerg Infect Dis"},{"key":"2026080410183612800_ofag452-B9","doi-asserted-by":"crossref","first-page":"15258","DOI":"10.1038\/s41598-018-33583-9","article-title":"Probiotics and carriage of Streptococcus pneumoniae serotypes in Danish children, a double-blind randomized controlled trial","volume":"8","author":"Fjeldh\u00f8j","year":"2018","journal-title":"Sci Rep"},{"key":"2026080410183612800_ofag452-B10","doi-asserted-by":"crossref","first-page":"20155","DOI":"10.2807\/ese.17.17.20155-en","article-title":"The Danish vaccination register","volume":"17","author":"Grove Krause","year":"2012","journal-title":"Euro Surveill"},{"key":"2026080410183612800_ofag452-B11","doi-asserted-by":"crossref","first-page":"ofad365","DOI":"10.1093\/ofid\/ofad365","article-title":"Decreased pneumococcal carriage among older adults in Denmark during the COVID-19 lockdown","volume":"10","author":"Tinggaard","year":"2023","journal-title":"Open Forum Infect Dis"},{"key":"2026080410183612800_ofag452-B12","doi-asserted-by":"crossref","first-page":"1088.e1","DOI":"10.1016\/j.cmi.2019.11.024","article-title":"Differentiation between Streptococcus pneumoniae and other viridans group streptococci by matrix-assisted laser desorption\/ionization time of flight mass spectrometry","volume":"26","author":"Yahiaoui","year":"2020","journal-title":"Clin Microbiol Infect"},{"key":"2026080410183612800_ofag452-B13","volume-title":"Laboratory methods for the diagnosis of meningitis caused by Neisseria meningitidis, Streptococcus pneumoniae, and Haemophilus influenza: WHO manual","author":"Castillo DBCMLRLLRLSMJJJX","year":"2011","edition":"2nd ed"},{"key":"2026080410183612800_ofag452-B14","doi-asserted-by":"crossref","first-page":"e60520","DOI":"10.1371\/journal.pone.0060520","article-title":"Superiority of trans-oral over trans-nasal sampling in detecting Streptococcus pneumoniae colonization in adults","volume":"8","author":"Trzci\u0144ski","year":"2013","journal-title":"PLoS One"},{"key":"2026080410183612800_ofag452-B15","doi-asserted-by":"crossref","first-page":"e0195799","DOI":"10.1371\/journal.pone.0195799","article-title":"Pneumococcal carriage in children and their household contacts six years after introduction of the 13-valent pneumococcal conjugate vaccine in England","volume":"13","author":"Southern","year":"2018","journal-title":"PLoS One"},{"key":"2026080410183612800_ofag452-B16","doi-asserted-by":"crossref","first-page":"e2680","DOI":"10.1093\/cid\/ciaa1551","article-title":"Influenza-like illness exacerbates pneumococcal carriage in older adults","volume":"73","author":"Miellet","year":"2021","journal-title":"Clin Infect Dis"},{"key":"2026080410183612800_ofag452-B17","doi-asserted-by":"crossref","first-page":"614","DOI":"10.4161\/hv.23253","article-title":"Carriage of Streptoccoccus pneumoniae in healthy adults aged 60 years or over in a population with very high and long-lasting pneumococcal conjugate vaccine coverage in children","volume":"9","author":"Ansaldi","year":"2013","journal-title":"Hum Vaccin Immunother"},{"key":"2026080410183612800_ofag452-B18","doi-asserted-by":"crossref","first-page":"1590","DOI":"10.1093\/infdis\/jiaa558","article-title":"Dynamics of pneumococcal carriage in adults: a new look at an old paradigm","volume":"223","author":"Almeida","year":"2021","journal-title":"J Infect Dis"},{"key":"2026080410183612800_ofag452-B19","doi-asserted-by":"crossref","first-page":"2","DOI":"10.1186\/s12979-016-0057-0","article-title":"Pneumococcal colonization in older adults","volume":"13","author":"Esposito","year":"2016","journal-title":"Immun Ageing"},{"key":"2026080410183612800_ofag452-B20","doi-asserted-by":"crossref","first-page":"5398","DOI":"10.1016\/j.vaccine.2020.06.047","article-title":"Use of seasonal influenza and pneumococcal polysaccharide vaccines in older adults to reduce COVID-19 mortality","volume":"38","author":"Thindwa","year":"2020","journal-title":"Vaccine"},{"key":"2026080410183612800_ofag452-B21","doi-asserted-by":"crossref","first-page":"1473","DOI":"10.1007\/s10096-022-04513-5","article-title":"Effectiveness of the 23-valent pneumococcal polysaccharide vaccine against invasive pneumococcal disease among 948,263 individuals \u226565 years of age: a Danish cohort study","volume":"41","author":"Nielsen","year":"2022","journal-title":"Eur J Clin Microbiol Infect Dis"},{"key":"2026080410183612800_ofag452-B22","doi-asserted-by":"crossref","first-page":"292","DOI":"10.1097\/QCO.0b013e3283531b0f","article-title":"Use of pneumococcal polysaccharide vaccine in children","volume":"25","author":"Borrow","year":"2012","journal-title":"Curr Opin Infect Dis"},{"key":"2026080410183612800_ofag452-B23","doi-asserted-by":"crossref","first-page":"8373","DOI":"10.1038\/s41598-020-65399-x","article-title":"Re-evaluation of Streptococcus pneumoniae carriage in Portuguese elderly by qPCR increases carriage estimates and unveils an expanded pool of serotypes","volume":"10","author":"Almeida","year":"2020","journal-title":"Sci Rep"},{"key":"2026080410183612800_ofag452-B24","doi-asserted-by":"crossref","first-page":"5096","DOI":"10.1016\/j.vaccine.2019.06.052","article-title":"Pneumococcal carriage among adults aged 50 years and older with co-morbidities attending medical practices in Rome, Italy","volume":"37","author":"Valdarchi","year":"2019","journal-title":"Vaccine"},{"key":"2026080410183612800_ofag452-B25","doi-asserted-by":"crossref","first-page":"1094","DOI":"10.1016\/j.vaccine.2018.12.075","article-title":"Streptococcus pneumoniae colonization after introduction of 13-valent pneumococcal conjugate vaccine for US adults 65 years of age and older, 2015\u20132016","volume":"37","author":"Milucky","year":"2019","journal-title":"Vaccine"},{"key":"2026080410183612800_ofag452-B26","doi-asserted-by":"crossref","first-page":"34888","DOI":"10.1038\/srep34888","article-title":"Molecular surveillance on Streptococcus pneumoniae carriage in non-elderly adults; little evidence for pneumococcal circulation independent from the reservoir in children","volume":"6","author":"Wyllie","year":"2016","journal-title":"Sci Rep"},{"key":"2026080410183612800_ofag452-B27","doi-asserted-by":"crossref","first-page":"e335","DOI":"10.1097\/MD.0000000000000335","article-title":"A cross-sectional observational study of pneumococcal carriage in children, their parents, and older adults following the Introduction of the 7-valent pneumococcal conjugate vaccine","volume":"94","author":"Hamaluba","year":"2015","journal-title":"Medicine (Baltimore)"},{"key":"2026080410183612800_ofag452-B28","doi-asserted-by":"crossref","first-page":"540","DOI":"10.1016\/j.jinf.2020.06.028","article-title":"Upper airways colonisation of Streptococcus pneumoniae in adults aged 60 years and older: a systematic review of prevalence and individual participant data meta-analysis of risk factors","volume":"81","author":"Smith","year":"2020","journal-title":"J Infect"},{"key":"2026080410183612800_ofag452-B29","doi-asserted-by":"crossref","first-page":"2110","DOI":"10.1093\/aje\/kwz191","article-title":"Association of laboratory methods, colonization density, and age with detection of Streptococcus pneumoniae in the nasopharynx","volume":"188","author":"Sutcliffe","year":"2019","journal-title":"Am J Epidemiol"},{"key":"2026080410183612800_ofag452-B30","doi-asserted-by":"crossref","first-page":"859736","DOI":"10.3389\/fmicb.2022.859736","article-title":"It takes two to Tango: combining conventional culture with molecular diagnostics enhances accuracy of Streptococcus pneumoniae detection and pneumococcal serogroup\/serotype determination in carriage","volume":"13","author":"Miellet","year":"2022","journal-title":"Front Microbiol"},{"key":"2026080410183612800_ofag452-B31","doi-asserted-by":"crossref","first-page":"e0119875","DOI":"10.1371\/journal.pone.0119875","article-title":"Carriage of Streptococcus pneumoniae in aged adults with influenza-like-illness","volume":"10","author":"Krone","year":"2015","journal-title":"PLoS One"},{"key":"2026080410183612800_ofag452-B32","doi-asserted-by":"crossref","first-page":"4","DOI":"10.1016\/j.vaccine.2015.11.014","article-title":"Carriage of Streptococcus pneumoniae in asymptomatic, community-dwelling elderly in The Netherlands","volume":"34","author":"van Deursen","year":"2016","journal-title":"Vaccine"},{"key":"2026080410183612800_ofag452-B33","doi-asserted-by":"crossref","first-page":"4565","DOI":"10.1016\/j.vaccine.2016.07.031","article-title":"Unaltered pneumococcal carriage prevalence due to expansion of non-vaccine types of low invasive potential 8 years after vaccine introduction in Stockholm, Sweden","volume":"34","author":"Lindstrand","year":"2016","journal-title":"Vaccine"},{"key":"2026080410183612800_ofag452-B34","doi-asserted-by":"crossref","first-page":"e0194823","DOI":"10.1371\/journal.pone.0194823","article-title":"Increased carriage of non-vaccine serotypes with low invasive disease potential four years after switching to the 10-valent pneumococcal conjugate vaccine in The Netherlands","volume":"13","author":"Vissers","year":"2018","journal-title":"PLoS One"},{"key":"2026080410183612800_ofag452-B35","doi-asserted-by":"crossref","first-page":"1208","DOI":"10.1183\/13993003.01451-2015","article-title":"Effects of PCV7 and PCV13 on invasive pneumococcal disease and carriage in Stockholm, Sweden","volume":"47","author":"Galanis","year":"2016","journal-title":"Eur Respir J"},{"key":"2026080410183612800_ofag452-B36","doi-asserted-by":"crossref","first-page":"368","DOI":"10.1016\/j.jinf.2018.06.004","article-title":"The relative invasive disease potential of Streptococcus pneumoniae among children after PCV introduction: a systematic review and meta-analysis","volume":"77","author":"Balsells","year":"2018","journal-title":"J Infect"},{"key":"2026080410183612800_ofag452-B37","doi-asserted-by":"crossref","first-page":"421","DOI":"10.1186\/s12879-021-06103-w","article-title":"Molecular characterization and epidemiology of Streptococcus pneumoniae serotype 8 in Denmark","volume":"21","author":"Hansen","year":"2021","journal-title":"BMC Infect Dis"},{"key":"2026080410183612800_ofag452-B38","doi-asserted-by":"crossref","first-page":"613287","DOI":"10.3389\/fcimb.2020.613287","article-title":"Sugar-coated killer: serotype 3 pneumococcal disease","volume":"10","author":"Luck","year":"2020","journal-title":"Front Cell Infect Microbiol"},{"key":"2026080410183612800_ofag452-B39","doi-asserted-by":"crossref","first-page":"e0220453","DOI":"10.1371\/journal.pone.0220453","article-title":"Limited indirect effects of an infant pneumococcal vaccination program in an aging population","volume":"14","author":"van der Linden","year":"2019","journal-title":"PLoS One"},{"key":"2026080410183612800_ofag452-B40","doi-asserted-by":"crossref","first-page":"162","DOI":"10.1128\/CVI.00591-15","article-title":"Capsular polysaccharide (CPS) release by serotype 3 pneumococcal strains reduces the protective effect of anti-type 3 CPS antibodies","volume":"23","author":"Choi","year":"2016","journal-title":"Clin Vaccine Immunol"},{"key":"2026080410183612800_ofag452-B41","first-page":"1361","article-title":"Persistent circulation of vaccine serotypes and serotype replacement after 5 years of infant immunization with 13-valent pneumococcal conjugate vaccine in the United Kingdom","volume":"221","author":"Kandasamy","year":"2019","journal-title":"J Infect Dis"},{"key":"2026080410183612800_ofag452-B42","doi-asserted-by":"crossref","first-page":"647","DOI":"10.1093\/cid\/ciab1003","article-title":"Effect of oral streptococci expressing pneumococcus-like cross-reactive capsule types on World Health Organization recommended pneumococcal carriage detection procedure","volume":"75","author":"Ganaie","year":"2022","journal-title":"Clin Infect Dis"},{"key":"2026080410183612800_ofag452-B43","doi-asserted-by":"crossref","first-page":"13280","DOI":"10.1038\/s41598-017-13605-8","article-title":"External quality assurance for laboratory identification and capsular typing of Streptococcus pneumoniae","volume":"7","author":"Slotved","year":"2017","journal-title":"Sci Rep"},{"key":"2026080410183612800_ofag452-B44","doi-asserted-by":"crossref","first-page":"1366","DOI":"10.1093\/cid\/ciae383","article-title":"A phase 3 clinical study to evaluate the safety, tolerability, and immunogenicity of V116 in pneumococcal vaccine\u2013experienced adults 50 years of age or older (STRIDE-6)","volume":"79","author":"Scott","year":"2024","journal-title":"Clin Infect Dis"},{"key":"2026080410183612800_ofag452-B45","doi-asserted-by":"crossref","first-page":"e00478-20","DOI":"10.1128\/msphere.00478-20","article-title":"The challenges of using oropharyngeal samples to measure pneumococcal carriage in adults","volume":"5","author":"Boelsen","year":"2020","journal-title":"mSphere"},{"key":"2026080410183612800_ofag452-B46","doi-asserted-by":"crossref","first-page":"e97","DOI":"10.7717\/peerj.97","article-title":"Non-pneumococcal mitis-group streptococci confound detection of pneumococcal capsular serotype-specific loci in upper respiratory tract","volume":"1","author":"Carvalho M da","year":"2013","journal-title":"PeerJ"}],"container-title":["Open Forum Infectious Diseases"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/academic.oup.com\/ofid\/advance-article-pdf\/doi\/10.1093\/ofid\/ofag452\/69945214\/ofag452.pdf","content-type":"application\/pdf","content-version":"am","intended-application":"syndication"},{"URL":"https:\/\/academic.oup.com\/ofid\/article-pdf\/13\/8\/ofag452\/69945214\/ofag452.pdf","content-type":"application\/pdf","content-version":"vor","intended-application":"syndication"},{"URL":"https:\/\/academic.oup.com\/ofid\/article-pdf\/13\/8\/ofag452\/69945214\/ofag452.pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,8,4]],"date-time":"2026-08-04T14:31:28Z","timestamp":1785853888000},"score":1,"resource":{"primary":{"URL":"https:\/\/academic.oup.com\/ofid\/article\/doi\/10.1093\/ofid\/ofag452\/8741391"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2026,7,24]]},"references-count":46,"journal-issue":{"issue":"8","published-print":{"date-parts":[[2026,8,1]]}},"URL":"https:\/\/doi.org\/10.1093\/ofid\/ofag452","relation":{},"ISSN":["2328-8957"],"issn-type":[{"value":"2328-8957","type":"electronic"}],"subject":[],"published-other":{"date-parts":[[2026,8]]},"published":{"date-parts":[[2026,7,24]]},"article-number":"ofag452"}}