The Unvaccinated Child with Fever

This episode of PEM Currents: The Pediatric Emergency Medicine Podcast focuses on the approach to unvaccinated or undervaccinated children aged 3–36 months presenting to the ED with fever. Host Brad Sobolewski reviews differences in immune response, risk for serious and invasive bacterial infections, and outlines evaluation strategies including labs, imaging, and empiric antibiotics. He highlights data showing increased interventions in this population and calls for local guideline development. The episode emphasizes thoughtful, individualized care in the context of rising vaccine hesitancy and declining immunization rates.

Learning Objectives

• Compare the clinical presentation of bacterial infections in unvaccinated and undervaccinated children versus fully immunized children in the Emergency Department
• Assess the need for empiric antibiotics and diagnostic testing in an unvaccinated or undervaccinated child presenting with fever without source

Connect with Brad Sobolewski

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References

Curtis M, Kanis J, Wagers B, et al. Immunization status and the management of febrile children in the pediatric emergency department: what are we doing? Pediatr Emerg Care. 2023;39(1):1-5. doi:10.1097/PEC.0000000000002864

Finkel L, Ospina-Jimenez C, Byers M, Eilbert W. Fever without source in unvaccinated children aged 3 to 24 months: what workup is recommended? Pediatr Emerg Care. 2021;37(12):e882-e885. doi:10.1097/PEC.0000000000002249

Herz AM, Greenhow TL, Alcantara J, et al. Changing epidemiology of outpatient bacteremia in 3- to 36-month-old children after the introduction of the heptavalent-conjugated pneumococcal vaccine. Pediatr Infect Dis J. 2006;25(4):293-300. doi:10.1097/01.inf.0000207485.39112.bf

Kaufman J, Fitzpatrick P, Tosif S, et al. Faster clean catch urine collection (Quick-Wee method) from infants: randomised controlled trial. BMJ. 2017;357:j1341. doi:10.1136/bmj.j1341

Kuppermann N, Fleisher GR, Jaffe DM. Predictors of occult pneumococcal bacteremia in young febrile children. Ann Emerg Med. 1998;31(6):679-687. doi:10.1016/S0196-0644(98)70225-2

Rutman MS, Bachur R, Harper MB. Radiographic pneumonia in young, highly febrile children with leukocytosis before and after universal conjugate pneumococcal vaccination. Pediatr Emerg Care. 2009;25(1):1-7. doi:10.1097/PEC.0b013e318191dab2

Trippella G, Galli L, De Martino M, Lisi C, Chiappini E. Procalcitonin performance in detecting serious and invasive bacterial infections in children with fever without apparent source: a systematic review and meta-analysis. Expert Rev Anti Infect Ther. 2017;15(11):1041-1057. doi:10.1080/14787210.2017.1400907

Van den Bruel A, Thompson MJ, Haj-Hassan T, et al. Diagnostic value of laboratory tests in identifying serious infections in febrile children: systematic review. BMJ. 2011;342:d3082. doi:10.1136/bmj.d3082

Transcript

Note: This transcript was partially completed with the use of the Descript AI

 Welcome to PEM Currents: The Pediatric Emergency Medicine P odcast. As always, I’m your host, Brad Sobolewski, and this episode is gonna focus on a challenging yet. Unfortunately, timely clinical question, what do we do with the UN or under vaccinated child who presents to the emergency department with fever? So what are we gonna go over in this episode?

Well, we’re gonna compare the clinical presentation of bacterial infections in unvaccinated and unvaccinated children versus fully immunized children in the emergency department, and we will assess the need for empiric antibiotics and diagnostic testing in this challenging population. Now, before you listen to this episode, I will presume that you are all familiar with the recommended child and adolescent immunization schedule for children ages 18 and younger in the United States or wherever you live.

So I’ll pause for a moment so that you can review that. Great. Welcome back, and there’s a few definitions that I will use. Unvaccinated or unm. Immunized means that you have no vaccines. Unvaccinated or under immunized means that you have some but not all of your vaccines, and you should always verify vaccine status via history EMR records and state registries.

So I think the first important question to answer is, when is a child immunocompetent? And honestly, competency is sort of on a sliding scale, and a child is immunocompetent if they have a normally functioning immune system capable of m