Utility of basic clinical and laboratory parameters to predict Serious Bacterial Infection in children younger than 3 months old hospitalized for Febrile Syndrome without Source

Abstract

In 20% of children with febrile syndrome, it appears as fever of unknown origin (FUO) syndrome. Management strategies in this group have high sensitivity but low specificity.

Objectives: To characterize serious bacterial infections (SBI) in children younger than three months old hospitalized because of FUO syndrome and to evaluate the utility of clinical and laboratory parameters in the identification of patients that are at high risk of SBI.

Patients and Method: Prospective study in patients aged < 3 months hospitalized due to FUO syndrome between January 2014 and November 2015 in two pediatric hospitals in the Metropolitan Region. Inclusion criteria: age 4 days - 3 months, fever > 38ºC longer than 72 hours after onset without demonstrable cause. Exclusion criteria: antimicrobial use up to 7 days before admission, preterm infants < 34 weeks, birth weight < 2 kg, and immunocompromised. Demographic, clinical, and laboratory tests data were recorded as well as blood count and CRP, discharge diagnosis, and ruled out, probable or confirmed SBI.

Results: 32% of the patients were discharged with diagnosis of SBI, 28% with diagnosis of viral or probably viral infection, 34% with diagnosis of not specified FUO syndrome, and 6% due to other causes. There were no significant differences in the CRP value, altered WBCs count, toxic aspect, or hours of fever at the admission when comparing groups with and without SBI (p < 0.05). The combination of clinical and laboratory parameters showed 27% of sensitivity, 90% of specificity, 60% of PPV, and 71% of NPV.

Conclusion: It was not possible to establish clinical and laboratory parameters that allow the identification of children younger than 3 months old at high risk of SBI, however, they maintain their value as low risk indicators. It is necessary further investigation of other clinical and laboratory elements that allow discriminating SBI from viral infections.