Bacteremia in Young Children After Introduction of Conjugated Pneumococcal Vaccines

Prior to the widespread use of vaccines for pneumococcus and Haemophilus influenzae, occult bacteremia in healthy febrile children was not uncommon. Now, the rate of occult bacteremia, primarily caused by pneumococcus, is well below 1% in these children.

In a retrospective cohort study from Kaiser Permanente Northern California, researchers reviewed all cases of bacteremia in previously healthy children aged 3 to 36 months during three periods between 1998 and 2014: pre–7-valent pneumococcal conjugate vaccine (PCV-7); post–PCV-7/pre–PCV-13; and post–PCV-13.

Of nearly 58,000 cultures reviewed, 1% were positive for a pathogen. Over the study period, the rate of bacteremia dropped from 97 to 21 per 100,000 children per year and the rate of pneum…