Distribution of varicella-zoster virus DNA and gene products in tissues of a first-trimester varicella-infected fetus.

Precise information about varicella-zoster virus (VZV) infection in first-trimester fetuses remains sketchy. After varicella infection was diagnosed in a woman, her 12-week-old fetus was aborted and was investigated, by histological examination, virus culturing, polymerase chain reaction, in situ hybridization (ISH), and immunohistochemistry (IHC), for the presence of VZV infection. Only the results of the histological examination suggested the presence of alpha -herpesvirus infection, in the gastrointestinal tract and liver; results of ISH were positive for VZV, and results of IHC staining were positive for intermediate early protein 63 (IE63) but negative for glycoprotein E (gE), in the dorsal root ganglia (DRG), meninges, gastrointestinal tract, pancreas, smooth muscle, liver, and placental trophoblast, indicating the presence of a nonproductive, latency-like VZV infection. Only the gastrointestinal tract and liver exhibited simultaneous staining for IE63 and gE, a result suggesting that active replication of VZV was present. In conclusion, widespread nonproductive VZV infection in the absence of histological clues is an early event in VZV infection in fetuses. The observed gene-expression pattern in most tissues resembles that of latent VZV infection in DRG. Latency-like infection in nonneural cell types may potentially reactivate, leading to multifocal necrosis, fibrosis, and dystrophic calcifications, as observed in advanced congenital varicella syndrome.