many cases, largely due to a lack of availability and the fact that such testing can take several days to perform.
These facts have led some authors to recom- mend that antigen testing be reserved for specific clinical circumstances. These include:1,2,4,6
• Negative initial Gram stain and CSF culture;
• Partially-treated patients with negative CSF culture; and
• Gram stain consistent with meningococcus, as identification of the serotype may guide vacci- nation programs in the setting of an outbreak. As technology improves and more rapid tech-
niques are developed, PCR may play a greater role in the diagnosis of bacterial meningitis. It has been suggested that PCR may be useful in establishing the diagnosis of viral meningitis in CSF culture- negative patients; therefore, shortening hospital stays and antibiotic therapy.2