{
  "abstract": "Background Febrile infants ≤90 days old with proven viral infections who may have concurrent serious bacterial infections (SBIs) remain a diagnostic dilemma. We aimed to compare the prevalence of SBIs and evaluate the performance of inflammatory markers in predicting SBIs, between infants with and without proven viral illness.Methods We conducted a secondary analysis of febrile infants ≤90 days old presenting with temperature ≥38°C to a tertiary paediatric emergency department in Singapore between 1 December 2017 and 31 July 2022. We compared SBI prevalence, performance of white blood cell (WBC), C-reactive protein (CRP), procalcitonin (PCT) and absolute neutrophil count (ANC), between infants with and without proven viral illness. We presented performance using sensitivity, specificity, positive and negative predictive values, and area under the receiver operating characteristic curve (AUC).Results Among 1783 infants, 261 (14.6%) had SBIs, and 653 (36.6%) had proven viral infections. The prevalence of SBI was lower in infants with proven viral illness compared with those without (5.05% vs 20.2%, p<0.001, OR=0.211, 95% CI 0.144 to 0.308). In both groups, CRP >20 mg/L had the highest sensitivity (60.6%, 95% CI 42.1% to 77.1% and 67.0%, 95% CI 60.4% to 73.0% for those with proven illness and those without) and ANC >10×10 9/L demonstrated the highest specificity (98.1%, 95% CI 96.7% to 99.1% and 93.1%, 95% CI 91.2% to 94.8%, for those with proven illness and those without), in predicting for SBIs. Using current thresholds, WBC, ANC, CRP and PCT performed with greater specificity but lower sensitivity among those with proven viral illness compared with those without. Differences in AUCs between both groups for the four inflammatory markers were only statistically significant with ANC >10×109/L.Conclusions Although febrile infants ≤90 days old with proven viral illnesses compared with those without were at lower risk of SBIs, current inflammatory markers thresholds may result in missed SBIs in this subgroup.Trial registration number NCT04103151.",
  "authors": [
    {
      "affiliations": [
        "Department of Paediatric Medicine, Kandang Kerbau Women's and Children’s Hospital, Singapore"
      ],
      "name": "Zhao Xiang Choa"
    },
    {
      "affiliations": [
        "Department of Children’s Emergency, Kandang Kerbau Women's and Children’s Hospital, Singapore"
      ],
      "name": "Gayatiri Raveentheran"
    },
    {
      "affiliations": [
        "Department of Paediatric Medicine, Kandang Kerbau Women's and Children’s Hospital, Singapore",
        "Singhealth-Duke NUS Paediatrics Academic Clinical Programme, Duke-NUS Medical School, Singapore"
      ],
      "name": "Zi Xean Khoo"
    },
    {
      "affiliations": [
        "Department of Children’s Emergency, Kandang Kerbau Women's and Children’s Hospital, Singapore",
        "Singhealth-Duke NUS Paediatrics Academic Clinical Programme and SingHealth-Duke NUS Emergency Medicine Academic Clinical Programme, Duke-NUS Medical School, Singapore"
      ],
      "name": "Gene Yong-Kwang Ong"
    },
    {
      "affiliations": [
        "Research Centre, Kandang Kerbau Women's and Children’s Hospital, Singapore"
      ],
      "name": "Lena Wong"
    },
    {
      "affiliations": [
        "Research Centre, Kandang Kerbau Women's and Children’s Hospital, Singapore"
      ],
      "name": "Rupini Piragasam"
    },
    {
      "affiliations": [
        "Department of Children’s Emergency, Kandang Kerbau Women's and Children’s Hospital, Singapore",
        "Singhealth-Duke NUS Paediatrics Academic Clinical Programme and SingHealth-Duke NUS Emergency Medicine Academic Clinical Programme, Duke-NUS Medical School, Singapore"
      ],
      "name": "Sashikumar Ganapathy"
    },
    {
      "affiliations": [
        "Department of Children’s Emergency, Kandang Kerbau Women's and Children’s Hospital, Singapore",
        "Singhealth-Duke NUS Paediatrics Academic Clinical Programme and SingHealth-Duke NUS Emergency Medicine Academic Clinical Programme, Duke-NUS Medical School, Singapore"
      ],
      "name": "Shu-Ling Chong"
    }
  ],
  "title": "Prevalence of serious bacterial infections and performance of inflammatory markers in febrile infants with and without proven viral illness",
  "uid": "dc048c38-1fb4-5054-b82b-acc7a8a467b8"
}