Chickenpox

• Case counts (2016-2025), population estimates (2016-2023), & population projections (2024-2025): Public Health Ontario.
• Query: Case counts of reportable diseases by public health unit and year. Toronto, ON: Ontario Agency for Health Protection and Promotion; extracted on March 9, 2026.

North Bay Parry Sound District Health Unit

• Chickenpox (varicella) fact sheet
• See also: Shingles

Schools and childcare centres should report cases daily, using the Chickenpox (Varicella) – Daily Reporting Form.

Report to the Health Unit within one business day by fax (705-482-0670) or phone at 705-474-1400 or toll free at 1-800-563-2808, ext. 5229 if chickenpox (varicella) is confirmed as per Ontario Regulation 135/18 and amendments under the Health Protection and Promotion Act, R.S.O., c.H.7.

For childcare and schools, no exclusion necessary, unless too ill to participate in activities or has a fever with behavioural change.

Follow the direction of your healthcare provider, public health case manager, or occupational health at your workplace.

Note: Exclusion guidelines may differ for healthcare workers.

Severe chickenpox (varicella) is preventable by vaccination. Check your vaccination records or call the Vaccine Preventable Diseases program at 705-474-1400 or toll free at 1-800-563-2808, ext. 5252 to book a vaccination appointment or to obtain additional information.

Immunizing patients

The routine immunization schedule for varicella is found in the Publicly Funded Immunization Schedules for Ontario.

Additional vaccine resources

Public Health Agency of Canada

• Varicella (chickenpox) vaccines: Canadian Immunization Guide

Immunize Canada

• Pocket Guide for Immunizers: Varicella (chickenpox)

Treatment of cases where indicated is under the direction of the attending healthcare provider. Varicella infection in pregnancy requires prompt treatment initiated within 24-48 hours of rash onset to prevent maternal and fetal sequelae.

For hospitalized cases, in addition to routine practices, airborne and contact precautions are recommended for a minimum of five days after onset of rash and until all lesions are crusted, which can be ≥ one week for immunocompromised patients. Airborne and contact precautions are recommended for neonates born to mothers with varicella infection.

Public Health Ontario

• Herpes simplex (HSV) and varicella zoster (VZV) viruses molecular testing
• Varicella - Serology
  • Serology for varicella zoster (IgG) may be indicated to determine immune status following a natural infection or post-vaccination and assess infants suspected of having congenital varicella syndrome.

Susceptible individuals (no history of varicella infection or vaccination) who are exposed to chickenpox may benefit from post-exposure prophylaxis to prevent or reduce severity of disease. Significant exposure includes close, indoor, or household contact with a person during their infectious period (one to two days before rash onset until all lesions are crusted).

Recommended PEP options:

Varicella vaccine

• For healthy, non-pregnant, susceptible individuals
• Administer one dose ASAP, ideally within 72 hours of exposure (effective up to five days)
• If the individual has had one previous dose, offer the second dose (if under age 50)
• MMRV not recommended for PEP use

Varicella zoster immune globulin (VarIg)

• For high-risk individuals when varicella vaccine is contraindicated, such as:
  • Immunocompromised persons
  • Pregnant individuals
  • Newborns of non-immune mothers exposed around delivery
• Administer within 96 hours of exposure (can be given up to 10 days)

For full guidelines, refer to the Canadian Immunization Guide - Varicella Chapter

Ministry of Health - Ontario Public Health Standards

• Infectious Disease Protocol: Appendix 1: Case Definitions and Disease-Specific Information: Chickenpox (varicella)

Public Health Agency of Canada

• Varicella (chickenpox)

Public Health Ontario

• Varicella (chickenpox)
• Surveillance report - Varicella in Ontario: Jan 1 to Dec 31, 2025