Bacteremia in Children

1. Definition
   1. Age under 36 months old
   2. Highest risk in younger infants (esp. <29 days)
   3. Fever (38 C or 100.4 F) without localizing signs
   4. Acute onset of fever persisting <1 week
   5. Assess for Occult Bacteremia
2. Causes: Common etiologies of Occult Bacteremia
   1. Newborns and first 1-3 months
      1. Group B Beta-hemolytic Streptococcus (Group B Strep)
      2. Escherichia coli K1 (ECK1)
      3. Listeria monocytogenes
         1. Rare in the United States
         2. Predominant in Spain
      4. Also consider Herpes Simplex Virus
   2. Children 3-36 months
      1. Most common prior to vaccines (much fewer cases now)
         1. Streptococcus Pneumoniae (covered by Prevnar)
         2. HaemophilusInfluenzae (covered by Hib Vaccine)
      2. Group A Beta-hemolytic Streptococcus
      3. Neisseria Meningitidis
3. Causes: Common conditions assoc. with Occult Bacteremia
   1. Otitis Media
   2. Bacterial Pneumonia
   3. Streptococcal Pharyngitis
   4. Meningitis
4. Signs: Toxic Findings suggestive of Occult Bacteremia
   1. See Yale Observation Scale
   2. See Rochester Criteria for Febrile Infants
   3. Cyanosis or other signs of poor perfusion
   4. Decreased activity
   5. Hyperventilation or Hypoventilation
   6. Does not interact with parents or environment
   7. Irritability
   8. Lethargy
   9. Hypotonic
   10. Tachycardia
   11. Weak eye contact
5. Diagnosis: Predictors of Occult Bacteremia
   1. Pre-Hib Era: Fever in non-toxic child ages 3-36 months
      1. Temperature <39.5 C: 1.6% Positive Blood Culture
      2. Temperature <34.0 C: 2.1% Positive Blood Culture
      3. Temperature <41.0 C: 3.5% Positive Blood Culture
      4. Temperature >41.0 C: 9.3% Positive Blood Culture
   2. Post-Hib Era: Fever in non-toxic child ages 3-36 months
      1. Temperature <39.5 C: 0.9% Positive Blood Culture
      2. Temperature <34.0 C: 1.1% Positive Blood Culture
      3. Temperature <40.5 C: 1.7% Positive Blood Culture
      4. Temperature <41.0 C: 2.4% Positive Blood Culture
      5. Temperature >40.9 C: 2.8% Positive Blood Culture
   3. Post-Hib Era: WBC in non-toxic child ages 3-36 months
      1. WBC <5k C: 0.0% Positive Blood Culture
      2. WBC <10k C: 0.1% Positive Blood Culture
      3. WBC <15k C: 0.5% Positive Blood Culture
      4. WBC <20k C: 3.5% Positive Blood Culture
      5. WBC <25k C: 6.8% Positive Blood Culture
      6. WBC <30k C: 7.2% Positive Blood Culture
      7. WBC >30k C: 18.3% Positive Blood Culture
6. Diagnosis: Findings suggestive of Occult Bacteremia
   1. Fever > 40 degrees Celsius
   2. White Blood Cell Count
      1. Leukopenia <5000
      2. Leukocytosis >15,000
   3. Absolute Neutrophil Count (ANC) > 10,000
   4. History of exposure to serious infection
   5. Rapid urine pneumococcal antigen assay
      1. Currently being researched for clinical application
      2. Test Sensitivity in pneumococcal bacteremia: 96%
      3. High false positive rate
      4. Neuman (2003) Pediatrics 112:1279-82
7. Pitfalls
   1. Urinalysis alone is insufficient
      1. Urine Culture in all cases
      2. Catheter or suprapubic specimen preferred
8. Management
   1. Age 0 months to 3 months
      1. See Fever Without Focus Management Birth to 3 Months
   2. Age 3 months to 36 months
      1. See Fever Without Focus Management 3 to 36 months
9. References
   1. Baraff (2000) Ann Emerg Med 36:611
   2. Baraff (1993) Pediatrics 92(1): 1-12
   3. Daaleman (1996) Am Fam Physician 54(8):2503
   4. Kimmel (1996) Fam Pract Recert 18(7):69-85
   5. Lee (1998) Arch Pediatr Adolesc Med 152:624-8
   6. Lopez (1997) Postgrad Med 101(2):241-52
   7. (1993) Ann Emerg Med 22(3):628-37