Pneumococcal bacteremia in febrile infants presenting to the emergency department 8 years after the introduction of pneumococcal conjugate vaccine in the Basque Country of Spain

Abstract

We included 3088 well-appearing infants aged between 3 and 36 months with fever without a source with a blood culture done as part of their study of fever. Rate of positive blood cultures for Streptococcus pneumoniae occult bacteremia (OB) was 0.58%. Rate of OB caused by PCV7-serotypes and nonvaccine serotypes were 0.16% and 0.42%, respectively. A total of 18 cases of S. pneumoniae OB were identified between January 1, 2006 and December 31, 2009. None of the 5 infants who had S. pneumoniae OB caused by vaccine serotypes had received PCV7. The decline in pneumococcal OB rates observed after PCV7 introduction in our area (Basque Country, Spain) continues 8 years later. There is no evidence of an OB rate increase caused by non-PCV7 serotypes.