Appropriate use of polymerase chain reaction for detection of herpes simplex virus 2 in cerebrospinal fluid of patients at an inner-city hospital

Polymerase chain reaction (PCR) tests that detect herpes simplex virus (HSV) DNA in cerebrospinal fluid (CSF) are increasingly used to diagnose central nervous system (CNS) infections caused by HSV. To determine proper utilization of this test at an inner-city hospital, we performed a case-control study of adult patients, with HSV detected in CSF by PCR. Retrospective review of characteristics of adult patients hospitalized between 1997 and 2000 with CSF positive for HSV was done and compared to control patients with suspected CNS infection and negative CSF PCR. CSF from 1174 patients was tested; 20 (1.7%) had HSV DNA detected, 19/20 were HSV-2 and 1 was HSV-1. The HSV-2 cases were females (74%), with a median age of 41 years, of African-American ethnicity (100%). Of the cases, 90% had acute aseptic meningitis versus 13% controls (P < .001). Recurrent meningitis occurred in 42% cases and 3% controls (P < .001). CSF parameters significantly associated with HSV-2 positivity was lymphocytic pleocytosis (median leukocyte, 475 cell/mm3, 90% lymphocytes) (P < .001). In conclusion, HSV-1 was rarely detected in CSF of patients with suspected CNS infection. HSV-2 is more frequent, predominantly in young African-American women with lymphocytic aseptic meningitis, and is often recurrent. PCR testing for HSV-2 in CSF at inner-city hospitals can be greatly reduced by the application of these parameters.