{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,10,21]],"date-time":"2026-10-21T03:43:28Z","timestamp":1792554208519,"version":"4.5.0"},"reference-count":22,"publisher":"Cambridge University Press (CUP)","license":[{"start":{"date-parts":[[2026,10,21]],"date-time":"2026-10-21T00:00:00Z","timestamp":1792540800000},"content-version":"unspecified","delay-in-days":0,"URL":"https:\/\/www.cambridge.org\/core\/terms"}],"content-domain":{"domain":["cambridge.org"],"crossmark-restriction":true},"short-container-title":["Infect. Control Hosp. Epidemiol."],"abstract":"Abstract<\/jats:title>\n \n Objectives:<\/jats:title>\n To investigate late-onset Group B Streptococcus (GBS) transmission dynamics in a neonatal intensive care unit (NICU) using whole-genome sequencing (WGS).<\/jats:p>\n <\/jats:sec>\n \n Setting:<\/jats:title>\n A 57-bed level III NICU in Toronto, Canada.<\/jats:p>\n <\/jats:sec>\n \n Patients:<\/jats:title>\n Neonates with late-onset GBS (LOGBS) identified, July 2023\u2013February 2024.<\/jats:p>\n <\/jats:sec>\n \n Methods:<\/jats:title>\n An outbreak management team oversaw the investigation, hygiene audits, and stakeholder communications. Canada\u2019s National Microbiology Laboratory performed WGS (Illumina) on outbreak and prior isolates. Core single nucleotide variant (SNV) phylogeny used SNVPhyl. Clinical data included age, infection type, maternal GBS status and outcome were reviewed. Three consecutive weekly point-prevalence surveys (PPS) were conducted using rectal and throat swabs.<\/jats:p>\n <\/jats:sec>\n \n Results:<\/jats:title>\n In August 2023, two LOGBS cases (bacteremia and meningitis) triggered the investigation. Two more LOGBS bacteremias occurred pending WGS results. Three of the 4 isolates matched a prior early-onset (day-1) case (0 SNVs; cluster 1, serotype Ia). The fourth was 1 SNV different from a conjunctivitis case detected a week later (cluster 2, serotype V). PPS revealed 5 asymptomatic cases genomically unrelated to either cluster. In February 2024, two further LOGBS cases (bacteremia; asymptomatic bacteruria) emerged. The first matched the mother\u2019s antepartum isolate with transmission to the second infant (0 SNVs; cluster 3, serotype IV). Hygiene audits identified gaps in hand and environmental safety; room proximity was the primary commonality. Following reinforcement of infection prevention measures, no further nosocomial GBS infections occurred through October 2025.<\/jats:p>\n <\/jats:sec>\n \n Conclusions:<\/jats:title>\n This prolonged NICU outbreak involved multiple serotypes. WGS was critical in distinguishing horizontal transmission from independent introductions, directly guiding targeted infection control interventions.<\/jats:p>\n <\/jats:sec>","DOI":"10.1017\/ice.2026.10503","type":"journal-article","created":{"date-parts":[[2026,10,21]],"date-time":"2026-10-21T03:27:51Z","timestamp":1792553271000},"page":"1-6","update-policy":"https:\/\/doi.org\/10.1017\/policypage","source":"Crossref","is-referenced-by-count":0,"title":["Leveraging whole-genome sequencing to manage a\n Streptococcus agalactiae<\/i>\n outbreak in a neonatal intensive care unit"],"prefix":"10.1017","author":[{"ORCID":"https:\/\/orcid.org\/0000-0001-9028-3195","authenticated-orcid":false,"given":"Halima","family":"Dabaja-Younis","sequence":"first","affiliation":[{"id":[{"id":"https:\/\/ror.org\/05deks119","id-type":"ROR","asserted-by":"publisher"}],"name":"Mount Sinai Hospital: Hospital Monte Sinai"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Allison","family":"McGeer","sequence":"additional","affiliation":[{"name":"Sinai Health System"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Vanessa G.","family":"Allen","sequence":"additional","affiliation":[{"name":"Sinai Health System"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-2682-8792","authenticated-orcid":false,"given":"Tony","family":"Mazzulli","sequence":"additional","affiliation":[{"name":"Sinai Health System"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Angelie","family":"Seguban","sequence":"additional","affiliation":[{"name":"Sinai Health System"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Andrea","family":"Morillo","sequence":"additional","affiliation":[{"name":"Sinai Health System"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-3941-5583","authenticated-orcid":false,"given":"Irene","family":"Martin","sequence":"additional","affiliation":[{"name":"Public Health Agency of Canada"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-1788-1794","authenticated-orcid":false,"given":"Alyssa R.","family":"Golden","sequence":"additional","affiliation":[{"name":"Public Health Agency of Canada"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Angela","family":"Neish","sequence":"additional","affiliation":[{"name":"Sinai Health System"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Yenge","family":"Diambomba","sequence":"additional","affiliation":[{"name":"Sinai Health System"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Jennie","family":"Johnstone","sequence":"additional","affiliation":[{"name":"Sinai Health System"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"56","published-online":{"date-parts":[[2026,10,21]]},"reference":[{"key":"S0899823X26105030_ref6","doi-asserted-by":"publisher","DOI":"10.1128\/Spectrum.01283-21"},{"key":"S0899823X26105030_ref21","first-page":"964","article-title":"Nosocomial transmission of bacteriophage type 7\/11\/12 Group B Streptococci in a special care nursery","volume":"134","author":"Boyer","year":"1980","journal-title":"Am J Dis Child"},{"key":"S0899823X26105030_ref8","doi-asserted-by":"publisher","DOI":"10.1111\/apa.17095"},{"key":"S0899823X26105030_ref9","doi-asserted-by":"publisher","DOI":"10.1093\/cid\/ciy174"},{"key":"S0899823X26105030_ref13","doi-asserted-by":"publisher","DOI":"10.1371\/journal.pone.0258030"},{"key":"S0899823X26105030_ref10","first-page":"e2","article-title":"Whole-genome sequencing for neonatal intensive care unit outbreak investigations: insights and lessons learned","volume":"1","author":"Sansom","year":"2021","journal-title":"Antimicrob Steward Healthc Epidemiol ASHE"},{"key":"S0899823X26105030_ref1","unstructured":"1. Group B Streptococcal Infections. Red Book: 2021\u20132024 Report of the Committee on Infectious Diseases, Red Book Online, American Academy of Pediatrics. https:\/\/publications.aap.org\/redbook\/book\/347\/chapter-abstract\/5756615\/Group-B-Streptococcal-Infections?redirectedFrom=fulltext. Accessed June 20, 2024."},{"key":"S0899823X26105030_ref4","doi-asserted-by":"publisher","DOI":"10.1016\/j.jinf.2019.11.008"},{"key":"S0899823X26105030_ref5","doi-asserted-by":"publisher","DOI":"10.1542\/peds.2019-1881"},{"key":"S0899823X26105030_ref19","doi-asserted-by":"publisher","DOI":"10.1097\/INF.0000000000001987"},{"key":"S0899823X26105030_ref11","volume-title":"Performance Standards for Antimicrobial Susceptibility Testing","year":"2024"},{"key":"S0899823X26105030_ref12","first-page":"e000116","article-title":"SNVPhyl: a single nucleotide variant phylogenomics pipeline for microbial genomic epidemiology","volume":"3","author":"Petkau","year":"2017","journal-title":"Microb Genom"},{"key":"S0899823X26105030_ref20","unstructured":"20. Verani, JR , McGee, L , Schrag, SJ. Division of Bacterial Diseases, National Center for Immunization and Respiratory Diseases, Centers for Disease Control and Prevention (CDC) (2010) Prevention of perinatal group B streptococcal disease--revised guidelines from CDC, 2010. MMWR Recomm reports Morb Mortal Wkly report Recomm reports. 2010;59:1\u201336."},{"key":"S0899823X26105030_ref2","doi-asserted-by":"publisher","DOI":"10.1097\/ANC.0000000000000769"},{"key":"S0899823X26105030_ref7","article-title":"Burden of infant group B Streptococcus disease and impact of maternal screening and antibiotic prophylaxis in Ontario, Canada: a population-based cohort study","author":"Fakhraei","year":"2024","journal-title":"Lancet Reg Health Am"},{"key":"S0899823X26105030_ref14","doi-asserted-by":"publisher","DOI":"10.1016\/j.vaccine.2020.08.052"},{"key":"S0899823X26105030_ref22","doi-asserted-by":"publisher","DOI":"10.3390\/microorganisms13071496"},{"key":"S0899823X26105030_ref15","doi-asserted-by":"publisher","DOI":"10.1128\/JCM.03554-13"},{"key":"S0899823X26105030_ref3","doi-asserted-by":"publisher","DOI":"10.1001\/jamapediatrics.2018.4824"},{"key":"S0899823X26105030_ref16","doi-asserted-by":"publisher","DOI":"10.1097\/00006454-200109000-00011"},{"key":"S0899823X26105030_ref17","doi-asserted-by":"publisher","DOI":"10.1128\/JCM.00355-16"},{"key":"S0899823X26105030_ref18","doi-asserted-by":"publisher","DOI":"10.1111\/apa.14558"}],"container-title":["Infection Control & Hospital Epidemiology"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.cambridge.org\/core\/services\/aop-cambridge-core\/content\/view\/S0899823X26105030","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,10,21]],"date-time":"2026-10-21T03:27:57Z","timestamp":1792553277000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.cambridge.org\/core\/product\/identifier\/S0899823X26105030\/type\/journal_article"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2026,10,21]]},"references-count":22,"alternative-id":["S0899823X26105030"],"URL":"https:\/\/doi.org\/10.1017\/ice.2026.10503","relation":{},"ISSN":["0899-823X","1559-6834"],"issn-type":[{"value":"0899-823X","type":"print"},{"value":"1559-6834","type":"electronic"}],"subject":[],"published":{"date-parts":[[2026,10,21]]},"assertion":[{"value":"\u00a9 The Author(s), 2026. Published by Cambridge University Press on behalf of The Society for Healthcare Epidemiology of America","name":"copyright","label":"Copyright","group":{"name":"copyright_and_licensing","label":"Copyright and Licensing"}}]}}