Varicella zoster virus Varicella zoster virus Varicella zoster virus or varicella-zoster virus (VZV) is one of eight herpesviruses known to infect humans. It causes chickenpox (varicella), a disease most commonly affecting children, teens, and young adults, and shingles (herpes zoster) in adults; shingles is rare in children. VZV is a worldwide pathogen known by many names: chickenpox virus, varicella virus, zoster virus, and human herpesvirus type 3 (HHV-3). VZV infections are species-specific to humans, but can survive in external environments for a few hours, maybe a day or two. VZV multiplies in the lungs, and causes a wide variety of symptoms. After the
Zymotic disease Zymotic disease Zymotic disease was a 19th-century medical term for acute infectious diseases, especially "chief fevers and contagious diseases (e.g. typhus and typhoid fevers, smallpox, scarlet fever, measles, erysipelas, cholera, whooping-cough, diphtheria, &c.)". Zyme or microzyme was the name of the organism presumed to be the cause of the disease. As originally employed by Dr W. Farr, of the British Registrar-General's department, the term included the diseases which were "epidemic, endemic and contagious," and were regarded as owing their origin to the presence of a morbific principle in the system, acting in a manner analogous to, although not identical with,