Communicability of varicella before rash onset: a literature review Journal Article uri icon



  • AbstractVaricella poses an occupational risk and a nosocomial risk for susceptible healthcare personnel and patients, respectively. Patients with varicella are thought to be infectious from 1 to 2 days before rash onset until all lesions are crusted, typically 4–7 days after onset of rash. We searched Medline, Embase, Cochrane Library and CINAHL databases to assess evidence of varicella-zoster virus (VZV) transmission before varicella rash onset. Few articles (7) contributed epidemiologic evidence; no formal studies were found. Published articles reported infectiousness at variable intervals before rash onset, between <1 day to 4 days prior to rash, with 1–2 patients for each interval. Laboratory assessment of transmission before rash was also limited (10 articles). No culture-positive results were reported. VZV DNA was identified by PCR before rash onset in only one study however, PCR does not indicate infectivity of the virus. Based on available medical literature, VZV transmission before rash onset seems unlikely, although the possibility of pre-rash, respiratory transmission cannot be entirely ruled out.

publication date

  • January 1, 2021

has restriction

  • gold

Date in CU Experts

  • January 11, 2023 1:45 AM

Full Author List

  • Marin M; Leung J; Lopez AS; Shepersky L; Schmid DS; Gershon AA

author count

  • 6

Other Profiles

International Standard Serial Number (ISSN)

  • 0950-2688

Electronic International Standard Serial Number (EISSN)

  • 1469-4409

Additional Document Info


  • 149


  • e131