Meningitis in older patients: how to diagnose and treat a deadly infection.

Studies of bacterial meningitis have documented a peak of incidence among persons age 60 and older. The most common bacterial pathogens in these patients differ from those seen in children. Presentation of meningitis in older patients may be atypical; fever is not a consistent finding, and nonspecific symptoms such as confusion are often seen. Nuchal rigidity is not as sensitive nor as specific a sign as in younger patients. Definitive diagnosis relies on interpretation of CSF studies. Ampicillin plus a third-generation cephalosporin should be administered for community-acquired meningitis until Gram's stain and culture results return. Cases of S pneumoniae meningitis may require varying strategies, based upon the degree of penicillin resistance.