Background: In many academic centers it is standard practice to hospitalize all febrile infants younger than two months of age, whereas in community settings such infants are often cared for as outpatients.
Methods: We conducted a controlled study of 747 consecutive infants 29 through 56 days of age who had temperatures of at least 38.2 degrees C. After a complete history taking, physical examination, and sepsis workup, the 460 infants with laboratory or clinical findings suggestive of serious bacterial illness were hospitalized and treated with antibiotics. The screening criteria for serious bacterial illness included a white-cell count of at least 15,000 per cubic millimeter, a spun urine specimen that had 10 or more white cells per high-power field or that was positive on bright-field microscopy, cerebrospinal fluid with a white-cell count of 8 or more per cubic millimeter or a positive Gram's stain, or a chest film showing an infiltrate. The 287 infants who had unremarkable examinations and normal laboratory results were assigned to either inpatient observation without antibiotics (n = 148) or outpatient care without antibiotics but with reexaminations after 24 and 48 hours (n = 139).
Results: Serious bacterial illness was diagnosed in 65 infants (8.7 percent). Of these 65 infants, 64 were identified by our screening criteria for inpatient care and antibiotic treatment (sensitivity = 98 percent; 95 percent confidence interval, 92 to 100). Of the 287 infants assigned to observation and no antibiotics, 286 (99.7 percent) did not have serious bacterial illness. Only two infants assigned to outpatient observation were subsequently admitted to the hospital; neither was found to have a serious illness. Outpatient care without antibiotics of the febrile infants at low risk for serious illness resulted in a savings of about $3,100 per patient.
Conclusions: With the use of strict screening criteria, a substantial number of febrile one-to-two-month-old infants can be cared for safely as outpatients and without antibiotics.