The Windsor-Essex County Health Unit (WECHU) has identified an increase in measles activity in Windsor-Essex County through wastewater surveillance. Although the provincial measles outbreak was declared over last October, wastewater surveillance continues to detect a measles signal in the community. Localized peaks in the wastewater viral signal were observed throughout spring 2026, with the most notable increase occurring during the week of April 5, 2026. According to WECHU’s Infectious Disease Data Dashboard, the average weighted measles wastewater signal increased during the last week of June.1
In light of this increase, WECHU is reminding healthcare providers to encourage clients to remain up to date with recommended immunizations, including measles-containing vaccine when eligible, and to consider measles in patients presenting with compatible symptoms. Symptoms may include high fever, severe cough, runny nose, and red, watery eyes. Individuals at highest risk for severe outcomes from measles include people who are immunocompromised, people who are pregnant, and infants and children under 5 years of age.2
Healthcare providers are encouraged to take the following actions:
- Review patient immunization records and identify those who are not up to date with measles-containing vaccine.
- Counsel patients on the importance of vaccination before potential exposure, particularly those at higher risk for severe outcomes.
- Recommend and administer measles-containing vaccine (MMR/MMRV) to eligible patients.
- Consider measles as a differential diagnosis for patients with compatible signs and symptoms, especially if they are unvaccinated, under-immunized, or have had potential exposure.
- Ensure appropriate measles testing is completed, including a nasopharyngeal swab/aspirate or throat swab for PCR, blood specimen for serology, and clean-catch urine for PCR.
- Report suspected or confirmed diseases of public health significance (DOPHS) promptly to WECHU.
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