Fetal varicella syndrome: disruption of neural development and persistent inflammation of non-neural tissues

Primary varicella tester virus (VZV) infection during pregnancy is rare. If it occurs between the 8th and 20th week of gestation, fetal varicella syndrome results in 1-2% of the fetuses. We report about a varicella infection that affected a pregnant mother in the 12th week of gestation. At 33 weeks, a premature girl was born with destruction of neurons in spinal cord, spinal ganglia and plexus myentericus, and secondary developmental disturbance including mummification of one arm and segmental intestinal atresia. The brain did not show any abnormalities. However, VZV DNA could be detected by PCR in tissues from the brain and spinal ganglia. Chronic necrotizing inflammation was found in the placenta, fetal membranes, and one ovary. These locations showed nuclear inclusions which by in-situ-hybridization were proven to be VZV derived. This case demonstrates that in the fetal age, 'neurotropism' of VZV signifies severe destruction but not necessarily persistent inflammation of neural tissue. However, due to the inefficient fetal immune system, inflammation can go on for weeks, preferentially in non-neural tissues.