Featured Story #2 - Disease Prevention
Measles Outbreak Response
The Windsor-Essex County Health Unit’s (WECHU) Infectious Disease Prevention (IDP) Department oversees the Communicable Disease and Outbreak Management (CDOM) Program, which is responsible for the surveillance, investigation, and management of Diseases of Public Health Significance (DoPHS) reported in Windsor-Essex County (WEC).
In 2025, the CDOM team led local case and contact management throughout the multi- jurisdictional measles outbreak in Ontario, which resulted in 2,376 reported cases provincially between October 2024 to October 2025. Local transmission began in early March 2025 with the first laboratory-confirmed case identified in WEC. April represented the highest period of local transmission, with 82 confirmed cases reported during that month alone.
The WECHU team investigated and managed 150 confirmed measles cases and conducted extensive contact tracing to support timely public health follow‑up. This work included organizing mass post‑exposure prophylaxis clinics in collaboration with the multidisciplinary team to ensure exposed individuals received appropriate care. Multiple exposure sites were identified, and 163 public health alerts were issued to inform the community and reduce further transmission.
Comprehensive outreach and targeted educational materials were developed for key community partners, such as health care providers, schools, and childcare centres to support measles preparedness and outbreak response. Resources included a parent-focused guide to increase awareness of prevention strategies, symptom recognition, and recommended actions following exposure, as well as a measles risk assessment tool to support decision-making after potential exposure.
Key lessons from the 2025 measles response in WEC included the importance of maintaining high vaccination coverage, strengthening healthcare provider awareness, ensuring rapid public communication about exposure risks, and prioritizing timely case and contact management.
School Age Immunizations
Public health units in Ontario are required by law through the Immunization of School Pupils Act (ISPA) to maintain records and ensure children attending school have their required vaccines. Parents/guardians must report immunizations to their local health unit.
The WECHU offers immunization programs and services that protect school aged children and the community they live in from vaccine-preventable diseases like measles and chicken pox. In the fall of 2025, the immunization records of all enrolled elementary and secondary students in Windsor and Essex County (WEC) were reviewed (66,522 records). Of these, 13% had incomplete immunization records.
In 2025, the WECHU:
- Provided 448 student immunization clinics.
- Administered 22,771 doses of vaccines to WEC students.
- Immunized 10,442 WEC students.
Vaccine Management
The WECHU works year-round to ensure publicly funded vaccines are available to health care providers across WEC. This includes managing vaccine inventory and coordinating distribution to community providers, hospitals, and long-term care facilities.
The WECHU also conducts annual vaccine fridge inspections at provider sites across WEC to verify that vaccines are being stored in accordance with Ontario Ministry of Health guidelines. The WECHU also provide ongoing education and support to vaccine providers on proper storage and handling practices. These efforts help ensure that vaccines administered across WEC are safe and effective.
In 2025, the WECHU:
- Distributed 316,559 vaccine doses to WEC health care providers.
- Completed 393 vaccine fridge inspections.