Reverse transcriptase-linked PCR was used to determine the prevalence of varicella-zoster virus (VZV) gene 21 transcription in latently infected human ganglia. Under conditions wherein reverse transcriptase-linked PCR detected > or = 1,000 transcripts, VZV gene 21 RNA, but not VZV gene 40 RNA, was found in ganglia but not other tissues from five of seven humans.