Varicella-zoster viruses. Coloured Transmission Electron Micrograph (TEM) of Varicella-zoster viruses. They cause chickenpox and shingles in humans. The rounded viruses are sectioned through to show DNA genetic material (red) surrounded by a protein coat (green). At lower right is part of an infected cell (yellow). Chickenpox is a highly infectious illness mainly affecting children. A childhood attack of chickenpox produces immunity to the disease. The virus, however, remains latent and if reactivated produces shingles in adults. Shingles causes pain in locally infected nerves together with a blistering of the overlying skin. Magnification: x60,000 at 6x7cm size.