Spread of varicella-zoster virus DNA to the environment from varicella patients who were treated with oral acyclovir

Objective: The purpose of the present study was to determine the degree of spread of varicella-zoster virus to the environment (VZV) from varicella patients who received oral acyclovir treatment. Methods: Over a period of 8 months, seven healthy children (two girls and five boys, 23-64 months of age) with varicella who visited Fujita Health University School of Medicine were treated with routine doses of oral acyclovir (ACV) for 5 days, commencing within 24 h after onset of the disease. Swab samples from the throats of patients and their family members as well as from air purifier filters in their houses were collected for 7 days as frequently as possible after starting treatment for the disease. The VZV DNA in the samples was identified by a sensitive polymerase chain reaction amplification assay. Results: The VZV DNA was detected in 33-100% of throat swab samples from varicella patients by day 7 of the disease, in 17-32% of throat swab samples from family members by day 4 and in 29% of filters from air purifiers by day 3. Conclusions: The results suggest a broad spread of VZV, probably by the airborne route, from the patients with varicella even after the administration of oral ACV.