Value of temperature for predicting invasive bacterial infection in febrile infants. A Spanish Pediatric Emergency Research Group (RISeuP-SPERG) Study
Infants ≤90 days old with fever without source (FWS) are in a higher risk of having an invasive bacterial infection (IBI) and a more aggressive management is usually recommended for this population. Few is known about the value of the fever degree for predicting the risk of IBI. Although most of the guidelines do not recommend modifying the management of these patients according to the fever degree, some authors recommend a different approach in well-appearing infant >28 days old depending on the maximum temperature detected.
Our objective was to analyze the value of temperature for predicting an IBI or and herpes infection in well-appearing infants 29-90 days old with FWS.
METHODS
Subanalysis of a prospective multicenter study including febrile infants ≤90 days old with FWS, carried out in 19 hospitals included in the Spanish Pediatric Emergency Research Group (RISeuP-SPERG) between October-2011 and September-2013. Axillary or rectal temperature ≥38°C at home or in the emergency department was considered fever. An IBI was diagnosed when a single pathogen was isolated in blood or cerebrospinal fluid (CSF). Herpes infection was diagnosed when there was a positive chain polymerase reaction (CPR) for Herpes virus in blood or CSF.
RESULTS
We recruited 3,401 infants. Of them, 2,253 were well-appearing infants >28 days old. In this subgroup, 43 (1.9%) were diagnosed with an IBI (39 positive blood culture, 3 positive CSF cultures and 1 patient with both positive cultures). One patient presented a positive CPR for herpes in CSF.
Area under the ROC curve for temperature for predicting an IBI was 0.623 (0.603-0.643) and for predicting specifically a bacterial positive culture or a herpes CRP in CSF was 0.651 (0.631-0671).
There were 17 IBI among well-appearing patients with less than 38.6ºC. There were no differences in rate of meningitis between patients with <38.6ºC and ≥38.6ºC (0.34% vs 0.31%, p=0.9).
Results were similar when analyzing specifically infants 29-60 days old and 61-90 days old.
CONCLUSION
Temperature itself has a low accuracy for ruling out an IBI in well-appearing infants 29-90 days old with FWS. Considering the prevalence in patients with lowest temperatures, we do not recommend modifying the management of these patients according to the maximum registered temperature.
