This transmission electron microscopic (TEM) image depicts numbers of cytomegalovirus (CMV) virions that were present in an unknown tissue sample.
CMV is one of the herpesviruses. This group of viruses includes the herpes simplex viruses (HSV), varicella-zoster virus (VZV), which causes chickenpox and shingles, and Epstein-Barr virus (EBV), which causes infectious mononucleosis, also known as mono. CMV is a common infection that is usually harmless. Once CMV is in a person's body, it stays there for life. Among every 100 adults in the United States, 50–80 are infected with CMV by the time they are 40 years old.