Spread of varicella in hospitalized children having no direct contact with an indicator zoster case and its prevention by a live vaccine.

Varicella spread from a child with zoster to a total of 3 susceptible infants in another room in a children's ward, although they had been strictly isolated. To prevent spread of the disease, the staffs and patients were doing their own washing and no source of natural infection could be found. The cases indicate that it is difficult to predict nosocomial varicella infection or to prevent spread of the disease simply by isolation in a children's ward. A total of 11 other children without history of varicella in the ward were given live varicella vaccine before or immediately after this event. None of these children developed symptoms of varicella and all the susceptible children who were vaccinated showed an antibody response.