External Validation of an Invasive Bacterial Infection Score for Young Febrile Infants

La prise en charge des nourrissons de 90 jours ou moins, fiévreux mais dans un bon état général

On constate des pratiques très variées en matière d'évaluation et de prise en charge des jeunes nourrissons fiévreux. Bien que la plupart des jeunes nourrissons fiévreux mais dans un bon état général soient atteints d'une maladie virale, il est essentiel de détecter ceux qui sont à risque de présenter des infections bactériennes invasives, notamment une bactériémie et une méningite bactérienne. Le présent document de principes porte sur les nourrissons de 90 jours ou moins dont la température rectale est de 38,0 °C ou plus, mais qui semblent être dans un bon état général. Il est conseillé d'appliquer les récents critères de stratification du risque pour orienter la prise en charge, ainsi que d'intégrer la procalcitonine à l'évaluation diagnostique. Les décisions sur la prise en charge des nourrissons qui satisfont aux critères de faible risque devraient refléter la probabilité d'une maladie, tenir compte de l'équilibre entre les risques et les préjudices potentiels et faire participer les parents ou les proches aux décisions lorsque diverses options sont possibles. La prise en charge optimale peut également dépendre de considérations pragmatiques, telles que l'accès à des examens diagnostiques, à des unités d'observation, à des soins tertiaires et à un suivi. Des éléments particuliers, tels que la mesure de la température, le risque d'infection invasive à Herpes simplex et la fièvre postvaccinale, sont également abordés.

Management of well-appearing febrile young infants aged ≤90 days

The evaluation and management of young infants presenting with fever remains an area of significant practice variation. While most well-appearing febrile young infants have a viral illness, identifying those at risk for invasive bacterial infections, specifically bacteremia and bacterial meningitis, is critical. This statement considers infants aged ≤90 days who present with a rectal temperature ≥38.0°C but appear well otherwise. Applying recent risk-stratification criteria to guide management and incorporating diagnostic testing with procalcitonin are advised. Management decisions for infants meeting low-risk criteria should reflect the probability of disease, consider the balance of risks and potential harm, and include parents/caregivers in shared decision-making when options exist. Optimal management may also be influenced by pragmatic considerations, such as access to diagnostic investigations, observation units, tertiary care, and follow-up. Special considerations such as temperature measurement, risk for invasive herpes simplex infection, and post-immunization fever are also discussed.

Prevalence of Invasive Bacterial Infection in Hypothermic Young Infants: A Multisite Study

OBJECTIVE

To determine the prevalence of bacteremia and meningitis (invasive bacterial infection [IBI]) in hypothermic young infants, and also to determine the prevalence of serious bacterial infections (SBI) and neonatal herpes simplex virus and to identify characteristics associated with IBI.

STUDY DESIGN

We conducted a retrospective cohort study of infants ≤90 days of age who presented to 1 of 9 hospitals with historical or documented hypothermia (temperature ≤36.0°C) from September 1, 2017, to May 5, 2021. Infants were identified by billing codes or electronic medical record search of hypothermic temperatures. All charts were manually reviewed. Infants with hypothermia during birth hospitalization, and febrile infants were excluded. IBI was defined as positive blood culture and/or cerebrospinal fluid culture treated as a pathogenic organism, whereas SBI also included urinary tract infection. We used multivariable mixed-effects logistic regression to identify associations between exposure variables and IBI.

RESULTS

Overall, 1098 young infants met the inclusion criteria. IBI prevalence was 2.1% (95% CI, 1.3-2.9) (bacteremia 1.8%; bacterial meningitis 0.5%). SBI prevalence was 4.4% (95% CI, 3.2-5.6), and neonatal herpes simplex virus prevalence was 1.3% (95% CI, 0.6-1.9). Significant associations were found between IBI and repeated temperature instability (OR, 4.9; 95% CI, 1.3-18.1), white blood cell count abnormalities (OR, 4.8; 95% CI, 1.8-13.1), and thrombocytopenia (OR, 5.0; 95% CI, 1.4-17.0).

CONCLUSIONS

IBI prevalence in hypothermic young infants is 2.1%. Further understanding of characteristics associated with IBI can guide the development decision tools for management of hypothermic young infants.

Performance of AAP Clinical Practice Guideline for Febrile Infants at One Pediatric Hospital

BACKGROUND

In the absence of procalcitonin, the American Academy of Pediatrics' clinical practice guideline (CPG) for evaluating and managing febrile infants recommends using previously untested combinations of inflammatory marker thresholds. Thus, CPG performance in detecting invasive bacterial infections (IBIs; bacteremia, bacterial meningitis) is poorly understood.

OBJECTIVE

To evaluate CPG performance without procalcitonin in detecting IBIs in well-appearing febrile infants 8 to 60 days old.

METHODS

For this cross-sectional, single-site study, we manually abstracted data for febrile infants using electronic health records from 2011 to 2018. We used CPG inclusion/exclusion criteria to identify eligible infants and stratified IBI risk with CPG inflammatory marker thresholds for temperature, absolute neutrophil count, and C-reactive protein. Because the CPG permits a wide array of interpretations, we performed 3 sensitivity analyses, modifying age and inflammatory marker thresholds. For each approach, we calculated area-under-the-receiver operating characteristic curve, sensitivity, and specificity in detecting IBIs.

RESULTS

For this study, 507 infants met the inclusion criteria. For the main analysis, we observed an area-under-the-receiver operating characteristic curve of 0.673 (95% confidence interval 0.652-0.694), sensitivity of 100% (66.4%-100%), and specificity of 34.5% (30.4%-38.9%). For the sensitivity analyses, sensitivities were all 100% and specificities ranged from 9% to 38%.

CONCLUSION

Findings suggest that the CPG is highly sensitive, minimizing missed IBIs, but specificity may be lower than previously reported. Future studies should prospectively investigate CPG performance in larger, multisite samples.