Chickenpox - hospitalised cases (Varicella-zoster virus)

Clinical criteria
Any person with

  • Acute onset of a diffuse vesicular rash developing within 24–48 hours and forming crusts (or crusting over) within 5 days
  • Complications may include pneumonia, encephalitis, bacterial infections, haemorrhagic complications

Note: Only hospitalised cases should be notified.

Laboratory criteria
At least one of the following three in the absence of recent vaccination:

  • Detection of VZV DNA in clinical samples (CSF, lesion fluid, blood or respiratory secretions) by PCR
  • Isolation of VZV from a clinical specimen
  • Seroconversion to VZV IgG positive or significant rise in VZV IgG antibody

Epidemiological criteria
An epidemiological link by human to human transmission

Case classification
A. Possible case
Any person meeting the clinical criteria
B. Probable case
Any person meeting the clinical criteria and with an epidemiological link to laboratory confirmed case
C. Confirmed case
Any person meeting the clinical and the laboratory criteria

Laboratory confirmation is encouraged for vaccinated cases. If positive, samples should be referred to discriminate between vaccine or wild type strain. 

Current as of: 24 January 2019