Chronic Uveitis in Guinea Pigs Infected with Varicella‐Zoster Virus ExpressingEscherichia coliβ‐Galactosidase

There is no small animal model that replicates chickenpox and herpes zoster, which are caused by varicella-zoster virus (VZV). Therefore, to detect VZV in tissues of infected animals, the Escherichia coli beta-galactosidase gene was inserted into the viral genome. Intravitreal inoculation of guinea pigs with virus-infected cells resulted in a chronic uveitis, with mononuclear cells in the vitreous cavity of the eye of nearly all animals. Staining with X-gal demonstrated the presence of VZV in the ciliary body or iris of approximately 40% of the animals and in retinal pigmented epithelial cells in 4 animals. X-gal staining showed VZV in the eye of 1 animal 140 days after inoculation. These experiments indicate that VZV expressing beta-galactosidase is useful for detecting virus in tissues and that VZV can cause a chronic uveitis in which virus can be detected in some animals for up to 4 months.