J Korean Pediatr Soc.  2002 Aug;45(8):967-972.

Usefulness of Low Risk Criteria for Serious Bacterial Infection Among Febrile Infants Younger than Three Months of Age

• Kim SH
• Jung JA
• Kim HS
• Yoo ES
• Sohn SJ
• Seo JW
• Lee SJ

Abstract

PURPOSE: A retrospective study was undertaken to evaluate the usefulness of low risk criteria for identifying febrile infants younger than three months unlikely to have serious bacterial infection.
METHODS
We conducted a retrospective study of 527 infants younger than three month with a axillary temperature >or=37.4degrees C. If they met the following all four criteria, appear well, WBC 5,000-20,000/mm3, urine stick WBC(-) and nitrite(-), CSF WBC <10/mm3, they were considered at low risk for serious bacterial infection(SBI). SBI was defined as a positive culture of urine, blood, or cerebrospinal fluid. The sensitivity, specificity, negative predictive value and positive predictive value of the low risk criteria were calculated.
RESULTS
Of 527 febrile infants, 110(21.0%) had serious bacterial infections. The 2.7% who met the low risk criteria had SBI and negative predictive value was 97.3%. SBI was diagnosed in 103 infants(38.6%) who didn't meet the low risk criteria including urinary tract infection(78.6%), most commonly, bacteremia(16.5%), bacterial meningitis(8.7%), Salmonella gastroenteritis(1%), osteomyelitis(1%), septic arthritis of hip joint(1%). There were no differences in the sensitivity and negative predictive value according to the monthly-age-group.
CONCLUSION
This low risk criteria to identify infants unlikely to have SBI early is available, however low risk infants must be carefully observed.

Keyword

Fever without source; Febrile infant; Bacteremia; Low risk criteria; Predictive; Serious bacterial infection

MeSH Terms

Arthritis, Infectious
Bacteremia
Bacterial Infections*
Cerebrospinal Fluid
Hip
Humans
Infant*
Retrospective Studies
Salmonella
Sensitivity and Specificity
Urinary Tract