Changing Epidemiology of Bacteremia in Infants Aged 1 Week to 3 Months
Pediatrics, 03/08/2012
Greenhow TL et al. – These study indicates bacteremia in young infants occurs infrequently and in only 2.2% of those who had a blood culture drawn. On the basis of the epidemiology of pathogens found in this large cohort, these data suggest a change in currently recommended presumptive antibiotic coverage in 1–week to 3–month–old infants with suspected bacteremia.
Methods- The authors conducted a retrospective analysis of all blood cultures collected at Kaiser Permanente Northern California on full–term, previously healthy infants presenting for care between 1 week to 3 months of age for whom a blood culture was drawn from January 1, 2005, through December 31, 2009.
- During the study period, 4255 blood cultures were collected from 160818 full–term infants.
- Only 2% of all blood cultures were positive for pathogens (93/4255), whereas 247 positive cultures were due to contaminants.
- The incidence rate of true bacteremia was 0.57 in 1000 full–term births.
- The most common pathogen was Escherichia coli (56%). Ninety–eight percent of infants with E coli bacteremia had a urinary tract infection.
- Group B Streptococcus and Staphylococcus aureus were the second and third most common pathogens, respectively.
- There were no cases of Listeria monocytogenes bacteremia or meningococcemia and only 1 case of enterococcal bacteremia.
- Ampicillin resistant pathogens accounted for 36% of organisms.



