Time to positivity of blood cultures for children with Streptococcus pneumoniae bacteremia

We report on a 3-year (1 January 1996 through 31 December 1999) retrospecti ve chart review of children with Streptococcus pneumoniae bacteremia to ide ntify the time to identification of growth of S. pneumoniae in blood cultur e and to attempt to identify clinical predictors of early versus late growt h of S. pneumoniae in culture. The time to detection of S. pneumoniae in bl ood culture for immunocompetent patients ranged from 4.4 to 25.9 hours (h), with a mean of 11.5 h (standard deviation, 2.8). There was no difference i n the time to detection for immunocompromised versus immunocompetent patien ts. The 10th and 90th deciles for time to detection among immunocompetent p atients were 9.2 and 14.0 h, respectively. There were no differences in whi te blood cell count, absolute neutrophil count, or height of fever between the lowest and highest decile groups. Ninety percent of blood cultures yiel ding S. pneumoniae are noted positive within 14 h, and no clinical or labor atory parameters accurately predicted early versus late growth of S. pneumo niae in blood culture.