Cerebrospinal fluid pleocytosis in children in the era of bacterial conjugate vaccines: distinguishing the child with bacterial and aseptic meningitis.

Although bacterial meningitis remains an important cause of childhood morbidity and mortality, the incidence of bacterial meningitis has greatly decreased with the advent of polysaccharide-protein conjugate vaccines in the past 2 decades. Most children with cerebrospinal fluid pleocytosis have aseptic rather than bacterial meningitis, raising the possibility that some patients may be managed as outpatients. In this article, we review the changing epidemiology of bacterial meningitis as well as the available clinical decision rules that may assist the clinician in distinguishing aseptic from bacterial meningitis in patients with cerebrospinal fluid pleocytosis.