Occult bacteraemia is uncommon in febrile infants who appear well, and close clinical follow-up is more appropriate than blood tests.

Abstract

The rate of paediatric occult bacteraemia after the introduction of the 13-valent pneumococcal conjugated vaccine is relatively unknown. We determined the rate, and identified isolated pathogens, in children aged three to 36months who presented to a paediatric emergency department with fever, but otherwise appeared well. We also analysed the yield of laboratory parameters traditionally considered risk factors for occult bacteraemia. Children aged three to 36months who were febrile, but otherwise appeared well, were included if they had blood tests in the paediatric emergency department between April 2010 and September 2012. Of the 591 patients, only six (1.0%) had a true bacterial pathogen and three of those were Streptococcus pneumoniae (0.5%). None of the children with pneumococcal bacteraemia had been immunised. The contaminant rate was 2.7%, and an elevated band count was the best predictor of occult bacteraemia, with positive and negative likelihood ratios of 10 and 0.4, respectively. The yield of the other laboratory parameters was very limited. In the era of the 13-valent pneumococcal conjugated vaccine, occult bacteraemia is an uncommon event in febrile children aged three to 36 who otherwise appear well and close follow-up should replace blood analysis in such cases.