Amplification of the six major human herpesviruses from cerebrospinal fluid by a single PCR

We used a novel type of primer system, a system that uses stair primers, in which the primer sequences are based on consensus sequences in the DNA pol ymerase gene of herpesvirus to detect herpesviruses by PCR. A single PCR in a single tube detected the six major herpesviruses that infect the central nervous system: herpes simplex virus type 1 (HSV-1), and type 2 (HSV-2), c ytomegalovirus (CMV), Epstein-Barr virus (EBV), varicella-zoster virus (VZV ), and human herpesvirus 6 (HHV-6). We used the technique to analyze 142 ce rebrospinal fluid (CSF) samples that had been stored at -80 degrees C and c ompared the results with those obtained previously for the same samples by standard, targeted PCR. Four hundred one targeted PCR tests had been run wi th the 142 samples to detect HSV-1, HSV3, CMV, and VZV; screening for EBV a nd HHV-6 was not prescribed when the samples were initially taken, Eighteen CSF samples tested positive by classic targeted PCR. The herpesvirus conse nsus PCR detected herpesviruses in 37 samples, including 3 samples with coi nfections and 17 viral isolates which were not targeted. Two samples identi fied as infected by the targeted PCR tested negative by the consensus PCR, and eight samples that tested positive by the consensus PCR were negative b y the targeted PCR. One hundred three samples scored negative by both the t argeted and the consensus PCRs. This preliminary study demonstrates the val ue of testing for six different herpesviruses simultaneously by a sensitive and straightforward technique rather than screening only for those viruses that are causing infections as suggested by clinical signs.