Varicella zoster virus and safe in adults with Human Immunodeficiency Virus. Chickenpox-like rashes were recognised and described by ancient civilizations; the relationship between zoster and chickenpox was not realized until 1888. It was in 1943 that Ruska noticed the similarity between virus particles isolated from the lesions of zoster and those from chickenpox. In 1974 the first vaccine was introduced for chickenpox. 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
Contagious disease illustrated classically by tuberculosis, which is clearly transmissible from person to person, but was not classically considered a contagious disease. In the present day, most sexually transmitted diseases are considered contagious, but only some of them are subject to medical isolation. Originally, the term referred to a "contagion" (a derivative of 'contact') or disease transmissible only by direct physical contact. In the modern day, the term has sometimes been broadened to encompass "any" communicable or infectious disease. Often the word can only be understood in context, where it is used to emphasise very infectious, easily transmitted, or especially severe communicable