Laboratory aids in the diagnosis of bacterial meningitis.

Bacterial meningitis is a uncommon but serious infectious disease. Critical care personnel have a great deal of difficulty in differentiating aseptic meningitis from partially treated meningitis from bacterial meningitis. Such a differentiation has obvious implications for therapy and prognosis. This article provides guidelines in using clinical criteria as well as cerebrospinal fluid parameters to diagnosis the commonly encountered infectious causes of meningitis. The current interpretation of laboratory tests such as countercurrent immunoelectrophoresis, latex agglutination, enzyme-linked immunosorbent assays, limulus assays, and lactic acid levels are discussed.