Bacteremia and bacterial meningitis occurred in 3.1% and 1.3% of infants </=28 days, respectively; 1.1% and 0.2% of infants 29-60 days, respectively. With a 1/500 chance of bacterial meningitis in infants 29-60 days, reasonable physicians may disagree on the merits of the lumbar puncture in this group.
Why does this matter?
Sometimes parents are reluctant to undergo the "full sepsis workup" in neonates 28 days or less, with lumbar puncture as the usual sticking point. One way to explain the risk to families is to say, "If you knew there was a >1/100 chance that walking out to your car your baby would be shot and killed or permanently brain damaged, would you take that chance?" Infants 29-60 days are a subject of intense debate and disagreement on the management.
Bad stuff growin' in there
This was a pre-planned secondary analysis of a prospective study in 26 EDs across the US of otherwise healthy infants >/= 36 weeks gestation with fever >/= 38 degrees C measured at home, in clinic, or in the ED. They examined 7335 infants <60 days; 4778 had blood cultures; 1.8% total were positive, 3.1% if </=28 days and 1.1% if 29-60 days. E. coli and group B streptococcus (GBS) were the two most common bacteria isolated. Infants </=28 days had bacterial meningitis in 1.1% (19/1,515); 0.2% (5/3,246) 29-60 days had bacterial meningitis.
Epidemiology of Bacteremia in Febrile Infants Aged 60 Days and Younger. Ann Emerg Med. 2018 Feb;71(2):211-216. doi: 10.1016/j.annemergmed.2017.07.488. Epub 2017 Oct 6.
Peer reviewed by Thomas Davis, MD.