{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,3,4]],"date-time":"2026-03-04T19:37:20Z","timestamp":1772653040053,"version":"3.50.1"},"reference-count":31,"publisher":"Public Library of Science (PLoS)","issue":"3","license":[{"start":{"date-parts":[[2026,3,4]],"date-time":"2026-03-04T00:00:00Z","timestamp":1772582400000},"content-version":"vor","delay-in-days":0,"URL":"http:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":["www.plosone.org"],"crossmark-restriction":false},"short-container-title":["PLoS One"],"abstract":"<jats:sec id=\"sec001\">\n                    <jats:title>Background<\/jats:title>\n                    <jats:p>Despite decades of study, the characteristics of infants with invasive group B streptococcus (GBS) late onset disease (LOD) (onset day 7\u201389 of life) and in particular very late onset disease (VLOD) (after day 89 of life) are not well described.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec id=\"sec002\">\n                    <jats:title>Materials and methods<\/jats:title>\n                    <jats:p>This was a retrospective cohort study of infants hospitalized in four Edmonton hospitals April 1, 1994 through June 30, 2022 with LOD or VLOD GBS invasive disease. Data were collected on demographics, day of onset of infection, clinical manifestations and outcomes.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec id=\"sec003\">\n                    <jats:title>Results<\/jats:title>\n                    <jats:p>There were 115 episodes of LOD in 111 infants of which 50 infants (45%) were preterm. Onset of initial LOD infection was on median day 27 (IQR 19\u201340.5) of life. All but one infant was bacteremic while 38\/111 (34%) had proven and 17\/111 (15%) had possible GBS meningitis. Five of 111 (5%) died before hospital discharge with all deaths probably due to GBS. There were 11 episodes of VLOD in 11 infants (8 [73%] preterm) presenting on median day 116 (IQR 103\u2013138) (range 93\u2013207) of life. Three (27%) had GBS meningitis. All 11 survived to discharge. As compared with infants with LOD, those with VLOD were less likely to be born vaginally (n\u2009=\u20093\/11 [27%] versus n\u2009=\u200972\/111 [65%] p\u2009=\u20090.036), more likely to be mechanically ventilated during their birth hospitalization (n\u2009=\u20095\/11 [45%] versus n\u2009=\u200917\/111 [15%]; p\u2009=\u20090.039), and more likely to have serious infection with other pathogens during their GBS admission (n\u2009=\u20093\/11 [27%] versus n\u2009=\u20094\/111 [4%]); p\u2009=\u20090.032). Serotype III accounted for 78% of LOD and 64% of VLOD cases.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec id=\"sec004\">\n                    <jats:title>Conclusion<\/jats:title>\n                    <jats:p>GBS remains a significant cause of infant morbidity and mortality. Infants with VLOD appear to have more complex medical histories prior to GBS infection than those with LOD. There is increasing evidence that GBS may sometimes be an opportunistic pathogen in infants over 89 days of age. This speaks of the need for increased surveillance for VLOD with further research into its epidemiology and underlying immunologic determinants.<\/jats:p>\n                  <\/jats:sec>","DOI":"10.1371\/journal.pone.0336839","type":"journal-article","created":{"date-parts":[[2026,3,4]],"date-time":"2026-03-04T18:29:31Z","timestamp":1772648971000},"page":"e0336839","update-policy":"https:\/\/doi.org\/10.1371\/journal.pone.corrections_policy","source":"Crossref","is-referenced-by-count":0,"title":["Shifting from an expected to an opportunistic pathogen: Comparison of cases of infant late and very late onset group B streptococcal (GBS) infection in a Canadian city over a 27-year period"],"prefix":"10.1371","volume":"21","author":[{"given":"Isoken","family":"Isah","sequence":"first","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Sneha","family":"Suresh","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-5276-2416","authenticated-orcid":true,"given":"Gregory J.","family":"Tyrrell","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Manoj","family":"Kumar","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-9831-5681","authenticated-orcid":true,"given":"Joan L.","family":"Robinson","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"340","published-online":{"date-parts":[[2026,3,4]]},"reference":[{"issue":"2","key":"pone.0336839.ref001","doi-asserted-by":"crossref","first-page":"63","DOI":"10.1542\/pir.2023-006154","article-title":"Neonatal Group B Streptococcus Disease","volume":"45","author":"SA Coggins","year":"2024","journal-title":"Pediatr Rev"},{"issue":"1","key":"pone.0336839.ref002","doi-asserted-by":"crossref","DOI":"10.1128\/cmr.00154-22","article-title":"Group B streptococcal infections in pregnancy and early life","volume":"38","author":"G Manuel","year":"2025","journal-title":"Clin Microbiol Rev"},{"issue":"4","key":"pone.0336839.ref003","doi-asserted-by":"crossref","DOI":"10.1016\/j.jpeds.2013.05.064","article-title":"Group B streptococcal colonization in 160 mother-baby pairs: a prospective cohort study","volume":"163","author":"A Berardi","year":"2013","journal-title":"J Pediatr"},{"issue":"3","key":"pone.0336839.ref004","doi-asserted-by":"crossref","DOI":"10.1542\/peds.2020-049561","article-title":"Breastfeeding and Risk of Late-Onset Group B Streptococcal Disease","volume":"148","author":"NS Ching","year":"2021","journal-title":"Pediatrics"},{"issue":"6","key":"pone.0336839.ref005","doi-asserted-by":"crossref","first-page":"521","DOI":"10.1016\/j.jinf.2019.11.008","article-title":"Hospital clusters of invasive Group B Streptococcal disease: A systematic review","volume":"79","author":"SM Collin","year":"2019","journal-title":"J Infect"},{"key":"pone.0336839.ref006","first-page":"751","article-title":"Statement on the prevention of early-onset group B streptococcal infections in the newborn","volume":"19","author":"Society of Obstetricians and Gynaecologists of Canada","year":"1997","journal-title":"J SOGC"},{"issue":"9","key":"pone.0336839.ref007","doi-asserted-by":"crossref","first-page":"826","DOI":"10.1016\/S1701-2163(16)30157-8","article-title":"RETIRED: The prevention of early-onset neonatal group B streptococcal disease","volume":"26","author":"Canadian Paediatric Society, Infectious Diseases Commitee","year":"2004","journal-title":"J Obstet Gynaecol Can"},{"issue":"2","key":"pone.0336839.ref008","doi-asserted-by":"crossref","first-page":"257","DOI":"10.1542\/peds.2009-1181","article-title":"Defining cerebrospinal fluid white blood cell count reference values in neonates and young infants","volume":"125","author":"LA Kestenbaum","year":"2010","journal-title":"Pediatrics"},{"issue":"3","key":"pone.0336839.ref009","article-title":"Epidemiological Characterization of Group B Streptococcus Infections in Alberta, Canada: An Update from 2014 to 2020","volume":"9","author":"A Ma","year":"2021","journal-title":"Microbiol Spectr"},{"issue":"7","key":"pone.0336839.ref010","doi-asserted-by":"crossref","first-page":"1774","DOI":"10.1128\/JCM.00355-16","article-title":"Epidemiology of Invasive Group B Streptococcal Disease in Alberta, Canada, from 2003 to 2013","volume":"54","author":"A Alhhazmi","year":"2016","journal-title":"J Clin Microbiol"},{"issue":"1","key":"pone.0336839.ref011","doi-asserted-by":"crossref","first-page":"165","DOI":"10.1084\/jem.142.1.165","article-title":"Multiple mouse-protective antibodies directed against group B streptococci. 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