Selection: Infant < 3 months of age with fever (defined as rectal temperature >= 38°C or >= 100.4°F)
Clinical findings:
(1) born at term (>= 37 weeks gestation) with uncomplicated nursery stay
(2) previously healthy
(3) no toxic manifestations
(4) no focal bacterial infection (except otitis media)
Laboratory findings:
(1) WBC count 5,000 - 15,000 per µL with < 1,500 band per µL or band-to-neutrophil ratio < 2
(2) Normal urinalysis (negative Gram stain on unspun urine, negative leukocyte esterase, negative nitrite, < 5 WBC per high power field)
(3) If diarrhea present, there is no haem and < 5 WBC per high power field on stool smear
(4) If lumbar puncture performed, CSF WBC count < 8 per µL and Gram stain negative
(5) No infiltrate on chest X-ray.
If all of these findings are present, then the infant is considered low risk and can be managed conservatively.
where:
• Premature infants have a high risk of serious bacterial infections during the first month after delivery.
• I assume that the "except otitis media" means that the child would be low risk if that is the only finding present.
• I assume the number of WBC in urine is on a spun urine sediment.
• I think that the WBC count criteria should use AND instead of OR.
• A band to segmented neutrophils ratio of 2 seems to indicate a fairly marked left shift.
