An outbreak of varicella-zoster virus infection among cancer patients.

An outbreak of varicella-zoster infection occurred among patients of the Medicine Branch, National Cancer Institute, National Institutes of Health. Epidemiologic investigation suggested that the outbreak was due to two distinct types of disease. One type was acquired without previous exposure to other diseased patients and invariably associated with dermatomal lesions. The other, an a typical form, was associated with person-to-person transmission and equivocal initial dermatomal distribution and had an incubation period of approximately 11 to 25 days. Despite the diagnosis of zoster, the latter probably was varicella, occurring in patients who were immunodeficient because of disease, debility, and chemotherapy.