Question From the Clinician: Fever and Bacteremia

Eric Biondi, MD* 2. Jennifer Murzycki, MD, PhD* 3. Shawn Ralston, MD† 4. Francis Gigliotti, MD* 1. *Golisano Children’s Hospital at Strong Memorial Hospital, Department of Pediatrics, University of Rochester Medical Center, Rochester, NY. 2. †Director of Hospital Medicine at Children's Hospital at Dartmouth, Hanover, NH. Is it necessary to monitor blood cultures for a full 48 hours to consider a febrile infant to be free of serious bacterial infection? Fever that could be due to bacteremia in infants is a common and serious problem faced by pediatricians. Because of their immature immune systems and nonspecific signs, infants are more susceptible to serious bacterial infections (SBIs) than adults. A wide variety of strategies have been developed for the assessment of febrile but well-appearing children younger than age 90 days, known collectively as the “rule out sepsis” evaluation. This clinical presentation is a common reason for infant hospitalization. However, it remains unclear how long blood cultures from this population need to be monitored and how long infants need to be hospitalized. The literature is inconclusive, and there is variability in current practice. A review of currently published data did not identify a clear-cut observational period. Randhawa et al suggest a 96-hour observational period, although it was not obvious from this study what type of culture detection system was used or whether the patients were symptomatic. (1) In 2011, Guerti et al demonstrated support for an evaluation period of more than 36 hours. (2) They found that 56% of blood cultures were positive for bacteremia after an incubation time of 24 hours, 89% after 48 hours, and 97% after 72 hours. Another large study by Kumar et al demonstrated similar results. (3) Interestingly, if all coagulase-negative Staphylococcus are removed in these …