Viable herpes simplex virus type 1 and varicella‐zoster virus in the trigeminal ganglia of human cadavers

Abstract

Human herpes simplex virus type 1 (HSV-1) and varicella-zoster virus (VZV) were isolated in the bilateral trigeminal ganglia of 12 human cadavers with no history of herpes-related symptoms within 1-5 days of death. Sixteen trigeminal ganglia were subjected to explant culture by using Vero cells, but no cytopathogenic effects (CPE) were observed. However, when another eight trigeminal ganglia were placed in a cell strainer and kept from direct contact with Vero cells during culture, CPE were clearly apparent in all cultures. The amount of DNA in the culture supernatants of 16 trigeminal ganglia decreased over time; 12 and 9 of these samples were PCR-positive for HSV-1 and VZV, respectively. In new Vero cells inoculated with supernatants collected 2 days after culture initiation, immunofluorescence staining revealed HSV-1 and VZV in 6 and 5 of 8 trigeminal ganglia, respectively. HSV-1 and VZV DNA was detected in supernatants collected 3 and 7 days after culture initiation and in Vero cells collected after culture completion, but real-time PCR revealed the DNA amounts decreased over time. There was less VZV DNA than HSV-1 DNA. These results demonstrate that infective HSV-1 and VZV can be isolated in culture, and confirm that viable HSV-1 and VZV persist in human trigeminal ganglia for some time after death.