{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,11,10]],"date-time":"2026-11-10T12:25:25Z","timestamp":1794313525339,"version":"4.9.0"},"reference-count":24,"publisher":"American Academy of Pediatrics (AAP)","issue":"2","content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":[],"published-print":{"date-parts":[[2025,2,1]]},"abstract":"<jats:sec>\n                    <jats:title\/>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>BACKGROUND<\/jats:title>\n                    <jats:p>Febrile young infants are at risk of invasive bacterial infections (IBIs; bacteremia or bacterial meningitis). American Academy of Pediatrics (AAP) guidelines recommend that when procalcitonin testing is unavailable, C-reactive protein (CRP), absolute neutrophil count (ANC) and temperature should be used to identify low-risk infants. We sought to determine the optimal combination of these inflammatory markers to predict IBI when procalcitonin is unavailable.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>METHODS<\/jats:title>\n                    <jats:p>This was a secondary analysis of prospectively collected data for all febrile infants aged 60\u00a0days or younger evaluated at a tertiary pediatric emergency department (January 2018\u00a0to July 2023). Previously healthy term infants aged 8\u00a0to 60\u00a0days with rectal temperatures of 38.0\u00b0C or greater meeting AAP inclusion\/exclusion criteria were analyzed. A decision rule was derived by classification and regression tree analysis with 10-fold cross-validation then compared to AAP-recommended thresholds of ANC\u2009\u2264\u20095200\/mm3, CRP\u2009\u2264\u200920\u00a0mg\/L, and temperature\u2009\u2264\u200938.5\u00b0C.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>RESULTS<\/jats:title>\n                    <jats:p>Among 1987\u00a0infants, 38 (1.9%) had IBIs. The AAP-recommended thresholds missed no IBIs (sensitivity: 100.0% [95% CI, 88.6%\u2013100.0%]; negative predictive value (NPV): 100.0% [95% CI, 99.5%\u2013100.0%]; specificity: 50.7% [95% CI, 48.5%\u201353.0%]). Optimal derived thresholds were CRP\u2009\u2264\u200922.2mg\/L, temperature\u2009\u2264\u200939.0\u00b0C, and ANC\u2009\u2264\u20094500\/mm3; urinalysis and age were not selected. The derived rule also missed no IBIs (sensitivity: 100.0% [95% CI, 88.6%\u2013100.0%]; NPV: 100.0% [95% CI, 99.7%\u2013100.0%]); however, specificity improved to 83.8% (95% CI, 82.1%\u201385.4%). Area under the receiver operating curve for the cross-validated rule (91.9% [95% CI, 91.1%\u201392.7%]) was higher than at AAP-recommended thresholds (75.4% (95% CI, 74.3%\u201376.5%]).<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>CONCLUSIONS<\/jats:title>\n                    <jats:p>The combination of ANC, CRP, and temperature at statistically derived thresholds improved diagnostic accuracy for identifying infants at low risk of IBIs compared to AAP-recommended thresholds.<\/jats:p>\n                  <\/jats:sec>","DOI":"10.1542\/peds.2024-068200","type":"journal-article","created":{"date-parts":[[2025,1,3]],"date-time":"2025-01-03T08:22:26Z","timestamp":1735892546000},"source":"Crossref","is-referenced-by-count":12,"title":["Optimizing Management of Febrile Young Infants Without Serum Procalcitonin"],"prefix":"10.1542","volume":"155","author":[{"given":"Brett","family":"Burstein","sequence":"first","affiliation":[{"name":"1Montreal Children\u2019s Hospital, Division of Pediatric Emergency Medicine, McGill University Health Centre, and the Department of Biostatistics, Epidemiology and Occupational Health, McGill University, Montreal, Quebec, Canada"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Caroline","family":"Wolek","sequence":"additional","affiliation":[{"name":"2McGill University, Montreal, Quebec, Canada"},{"name":"3University of Connecticut, Farmington, Connecticut"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Cassandra","family":"Poirier","sequence":"additional","affiliation":[{"name":"4Department of Anesthesiology, Pharmacology & Therapeutics, University of British Columbia, Vancouver, British Columbia, Canada"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Alexandra","family":"Yannopoulos","sequence":"additional","affiliation":[{"name":"5Research Institute of the McGill University Health Centre, Montreal, Quebec, Canada"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"T.","family":"Charles Casper","sequence":"additional","affiliation":[{"name":"6Department of Pediatrics, University of Utah School of Medicine, Salt Lake City, Utah"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Mohammed","family":"Kaouache","sequence":"additional","affiliation":[{"name":"5Research Institute of the McGill University Health Centre, Montreal, Quebec, Canada"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Nathan","family":"Kuppermann","sequence":"additional","affiliation":[{"name":"7Departments of Pediatrics and Emergency Medicine, George Washington University School of Medicine and Health Sciences, Washington, 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