• The febrile infants aged 0-90 days are vulnerable to serious illness.
• Well appearing infants, even those who have a viral source for their fever, have a disproportionately high rate of serious bacterial illness.
• Rectal temperature is the best method to confirm fever in infants. A fever (>/= 38°C) measured at home is considered febrile.
• Some febrile infants need a partial septic work-up (blood and urine cultures) and others require a full septic work-up (blood, urine, and CSF cultures).

Recently published decision aids (‘Step-by-step,’ ‘PECARN’) utilized pro-calcitonin testing – a test not widely available in British Columbia currently – will not be included in the discussion.

• Step-by-step.
• PECARN.
• Rochester.

Fever in infants 0-28 days and ill-appearing infants 29-60 days of age:

• Full-septic work-up should be performed, including blood, urine, and CSF cultures.
  • Admit for IV antibiotics and further monitoring.
  • Empiric antibiotics: Ampicillin and Cefotaxime is preferred over gentamicin.
  • Consider adding acyclovir in infants with:
    • A maternal history of HSV infection.
    • Presence of lesions suspicious for HSV.
    • A coagulopathy or elevated liver enzymes.
    • History of seizures or focal neurologic deficits.

Well-appearing, febrile infants age 29-60 days of age with no source:

• For infants who present with no viral source, a partial septic work-up including blood and urine cultures should be performed.
• Consider chest x-ray, stool culture, and nasopharyngeal swab.
• Once the partial septic work-up is completed, an additional decision aid (Rochester Criteria) can be used to determine whether these patients require intravenous antibiotics and admission to hospital.
• Well-appearing febrile infants aged 29-60 days who meet ALL of the following criteria may be discharged home with a follow-up appointment in 24 hours:
  • Infant > 37 weeks gestation.
  • No history of prior hospitalization.
  • No prolonged newborn nursery care or NICU admission.
  • WBC between 5 and 15×109/L (with bands less than 1.5×109/L).
  • Urine WBC of less than 5/HPF, (and urinalysis negative for nitrites or leukocyte esterase).
  • CRP less than 20 mg/L (if available).
  • Procalcitonin than 0.5 mcg/L (if available).
  • No prior antibiotics.
  • No unexplained jaundice.
  • No history of chronic illness.
• If the patient has a positive urinalysis (+leukocyte esterase, +nitrite, or WBC >5-10/hpf), the infant should be treated with antibiotics (typically intravenous). Well-appearing infants with access to close follow-up who have a UTI may be treated with oral antibiotics (broad-spectrum).

Bronchiolitis (rhinorrhea, cough):

The rate of urinary tract infection is still significant. If fever > 39C, or prolonged illness, a partial septic work-up should be completed, at minimum.

Infants 60-90 days of age:

Maintain a high index of suspicion for urinary tract infection in this population and consider urinalysis and culture in patients presenting without a clear viral source.

Consider further investigations if unwell, unimmunized, or has a prolonged illness.

1. Baraff, L. Management of Infants and Young Children with Fever without Source. Pediatric Annals 37:10, October 2008.

   
   

2. Aronson PL, Wang ME, Shapiro ED, Shah SS, DePorre AG, McCulloh RJ, et al. Risk stratification of febrile infants </=60 days old without routine lumbar puncture. Pediatrics. 2018;142(6):e20181879.

   
   

3. Levine D.A., Platt S.L., Dayan P.S. Risk of serious bacterial infection in young febrile infants with respiratory syncytial virus infections. Pediatrics. 2004;113:1728–1734.

   
   

4. Gomez B, Mintegi S, Bressan S, et al. Validation of the “step-by-step” approach in the management of young febrile infants. Pediatrics. 2016;138(2):e20154381

   
   

5. https://publications.aap.org/pediatrics/article/148/2/e2021052228/179783/Clinical-Practice-Guideline-Evaluation-and?autologincheck=redirected

   
   

6. EB Medicine – Evaluation and Management of the Febrile Young Infant in the Emergency Department (Infectious Disease CME)

   
   

7. CPS Position Statement – Urinary tract infection in infants and children: Diagnosis and Management.