Clinical and Laboratory “Low Risk” Criteria for Children Younger Than 3 Months with Fever and No Focus of Infection

Clinical criteria

  • Born at term (gestational age >/= 37 weeks)with uncomplicated nursery stay
  • Previously healthy infants
  • No toxic manifestations
  • No focal bacterial infection (except otitis media)

Laboratory criteria

  • White blood cell count 5-15 x 109/l, < 1.5 x 109 band cells/l, or band/neutrophil ratio< 2
  • Normal urine analysis results (negative Gram stain of unspun urine, negative leucocyte esterase and nitrite, fewer than five white blood cells per high power field)
  • When diarrhoea is present, no haem and fewer than five white blood cells per high power field
  • Fewer than 8 x 106 white blood cells/l in cerebrospinal fluid, if lumbar puncture is performed, and negative Gram stain findings in cerebrospinal fluid
  • No infiltrate on chest radiograph



1. Brook I. Unexplained fever in young children: how to manage severe bacterial infection. BMJ. 2003 Nov 8;327(7423):1094-7. [Medline]

Created: July 21, 2005