Laboratory diagnosis of common viral infections of the central nervous system by using a single multiplex PCR screening assay

Abstract

A multiplex PCR assay that detects the four commonest causes of viral meningitis and encephalitis in the United Kingdom (herpes simplex virus [HSV] type 1 [HSV-1], HSV type 2 [HSV-2], varicella-zoster virus [VZV], and enteroviruses) was developed, and its sensitivity was compared with those of similar assays described previously for this application. Compared to the previous assays, this single multiplex PCR assay had higher molecular sensitivities for the detection for each of the viruses and improved utility for routine use in a diagnostic laboratory. The assay was used to test a series of 1,683 consecutive cerebrospinal fluid (CSF) samples between June 1997 and March 1998 inclusively. Viral nucleic acid was detected in 138 (8.2%) of the CSF samples, including enteroviruses in 51 samples, HSV-2 in 33 samples, VZV in 28 samples, and HSV-1 in 25 samples. Compared to the accepted relative incidence of viral etiologies, aseptic meningitis due to HSV-2 infection was high, and in adult female patients with symptoms of aseptic meningitis, HSV-2 was the virus most commonly detected in the CSF.

FIG. 1

Screen 1-amplified viral nucleic acids from CSF samples and controls after agarose gel electrophoresis, ethidium bromide staining, and UV light transillumination. Lanes 1 and 12, 100- to 1,000-bp molecular ruler (Bio-Rad Laboratories Ltd., Hemel Hempstead, United Kingdom); lanes 2 and 11, control mixture containing HSV-1, VZV, and poliovirus type 2 nucleic acids at concentrations equivalent to those that give 10 PCRD₅₀s (HSV, 280 bp; VZV, 200 bp; and enterovirus, 144 bp); lanes 3, 6, and 10, negative nucleic acid extraction and amplification controls; lanes 4, 5, and 7 to 9, CSF samples containing HSV DNA (lane 4), VZV DNA (lane 7), enterovirus RNA (lane 8), or no detectable specific nucleic acid (lanes 5 and 9).