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

The purpose of a new study published in Revista Chilena de Pediatria was to characterize serious bacterial infections (SBI) in children younger than three months of age, 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.

This was a prospective study in infants below 3 months, hospitalized due to FUO syndrome, between January 2014 and November 2015—in two pediatric hospitals in the Metropolitan Region.

The results showed that 32% of the patients were discharged with a 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 values, altered WBCs counts or toxic aspect or hours of fever at admission, when comparing groups with and without SBI. The combination of clinical and laboratory parameters showed 27% of sensitivity, 90% of specificity, 60% of PPV and 71% of NPV.

It was concluded that it was not possible to establish clinical and laboratory parameters that allow the identification of children younger than 3 months of age, at high risk of SBI—yet, they maintain their value as low risk indicators. Further investigation of other clinical and laboratory elements that allow discriminating SBI from viral infections are necessary.

Source: Revista Chilena de Pediatria. 2020 Apr;91(2):199-208. doi: 10.32641/rchped.v91i2.1261.