5 Best of 2019: Most-Read Pediatrics Viewpoints

William T. Basco, Jr, MD, MS


January 21, 2020

#1: Bacterial Infections in Infants: The Times They Are A-Changin'

The organisms involved in serious bacterial infections in infants are changing—the result of improved screening, better treatment of women during pregnancy, and immunizations. Do our go-to drugs to treat suspected sepsis or meningitis also need to change?

A recent study conducted from 2011 to 2016 involving over 400 infants documented by culture to have an invasive bacterial infection (IBI) sought to answer this question. Most febrile infants seen in one of the participating EDs were found to have a viral illness. But 2%-5% had bacteremia and/or bacterial meningitis, with the peak incidence found in the second week of life. Whereas 80% of the infants were febrile at the time of presentation, only about one third were obviously ill-appearing and fewer than 1 in 10 had a clinically apparent infection on examination—a good reminder, should we need it, to treat every febrile infant as potentially serious.

About 1 in 5 of the infants with an IBI was determined to have bacteremia without meningitis. An additional 15% had bacterial meningitis with bacteremia, and just under 6% had bacterial meningitis without bacteremia. Group B streptococcus was the most common pathogen identified (36.7%), followed by Escherichia coli (30.8%), Staphylococcus aureus (9.7%), and Enterococcus species (6.6%).

Resistance to ampicillin occurred in approximately 29% of isolates. Virtually all (96%) infants with bacteremia without meningitis had pathogens susceptible to a combination of ampicillin plus either gentamicin or a third-generation cephalosporin. However, across sites, the median proportion of infants with a pathogen resistant to a third-generation cephalosporin alone was 13.3%, most frequently Enterococcus species.

The authors concluded that for most infants ≤ 60 days of age, a combination of ampicillin plus gentamicin or a third-generation cephalosporin would provide sufficient coverage, but treatment with cephalosporins alone would be insufficient for as many as 1 in 10 infants.


Probably the most important take-home point of this study is the fact that, potentially, 11% of the infants with a serious bacterial infection would not have been well served by treating empirically with only a third-generation cephalosporin. If practitioners can remember only one thing from this study, that is probably the most important. The other key take-home point is that while knowing what you're treating is always a great idea, adjusting medications as needed once isolates and their sensitivities are finalized may be even more important.

William T. Basco, Jr, MD, MS, is a professor of pediatrics at the Medical University of South Carolina and director of the Division of General Pediatrics. He is an active health services researcher and has published more than 60 articles in the peer-reviewed literature.

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