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Clinical features and diagnosis of acute bacterial meningitis in adults

Allan R Tunkel, MD, PhD, MACP
Section Editor
Stephen B Calderwood, MD
Deputy Editor
Anna R Thorner, MD


Meningitis is an inflammatory disease of the leptomeninges, the tissues surrounding the brain and spinal cord, and is defined by an abnormal number of white blood cells in the cerebrospinal fluid (CSF). The meninges consist of three parts: the pia, arachnoid, and dura maters. Bacterial meningitis reflects infection of the arachnoid mater and the CSF in both the subarachnoid space and the cerebral ventricles.

Approximately 1.2 million cases of bacterial meningitis occur annually worldwide [1]. Meningitis is among the 10 most common infectious causes of death and is responsible for approximately 135,000 deaths throughout the world each year. Neurologic sequelae are common among survivors.

The clinical and laboratory features of acute bacterial meningitis in adults will be reviewed here. The pathogenesis, epidemiology, treatment, prognosis, and prevention of acute bacterial meningitis in adults and issues related to acute bacterial meningitis in children and to chronic and recurrent meningitis are discussed separately. (See "Pathogenesis and pathophysiology of bacterial meningitis" and "Epidemiology of bacterial meningitis in adults" and "Initial therapy and prognosis of bacterial meningitis in adults" and "Treatment of bacterial meningitis caused by specific pathogens in adults" and "Bacterial meningitis in children older than one month: Clinical features and diagnosis" and "Bacterial meningitis in children older than one month: Treatment and prognosis" and "Approach to the patient with chronic meningitis" and "Approach to the adult with recurrent infections", section on 'Meningitis'.)


The epidemiology of and risk factors for bacterial meningitis are discussed in detail elsewhere, but the major epidemiologic issues in adults can be summarized as follows (see "Epidemiology of bacterial meningitis in adults"):

Bacterial meningitis can be community acquired or healthcare associated.

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Literature review current through: Nov 2017. | This topic last updated: Aug 17, 2016.
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