Blood Cultures in Pediatric Practice

Abstract

Occult pneumococcal bacteremia in infants was recognized as an entity a decade ago, 1.2 but the frequency of its occurrence was not appreciated until Klein and his associates at the Boston City Hospital (BCH) studied 600 consecutive febrile outpatients younger than 2 years of age. 3 They documented bacteremia in 3.2% of them, with Streptococcus pneumoniae the pathogen in nearly 80%. Subsequently, they documented the development of meningitis in 4% of the infants with unsuspected pneumococcemia. 4 Two risk factors, a rectal temperature ≥ 38.9 °C and a WBC count > 15,000/cu mm, present together in only 28% of the patients, were recognized to identify 79% of those with positive blood cultures. The following display presents rates from the BCH data: Of 1,000 febrile infants younger than 2 years of age, 769 have rectal temperature ≥ 38.9 °C. Of these 769 infants, 287 have WBC counts > 15,000/cu