First Human Case of West Nile Virus Confirmed in Waterloo Region

The Region of Waterloo Public Health has confirmed the first human case of West Nile virus in the area for 2024. This marks the second reported human case since the virus was first detected locally last year. The unusual warmth experienced in the region has contributed to a thriving mosquito population, extending their activity well into October.

According to Dr. Rabia Bana, Associate Medical Officer of Health, the persistent warm temperatures have led to a longer life cycle for mosquitoes in both the region and across Ontario. She emphasizes the importance of vigilance and protective measures against mosquito bites as residents enjoy outdoor activities.

Although most individuals infected with West Nile virus do not exhibit symptoms, those who do may experience mild fever, muscle aches, stiff neck, swollen glands, and skin rash following a mosquito bite. Health officials advise anyone experiencing these symptoms to seek medical attention promptly.

Dr. Bana urges the community to remain cautious as the season progresses: “As we wait for cooler fall weather and the first frost, residents should continue to take precautions to protect themselves from mosquito bites while spending time outdoors.” She also recommends checking properties for standing water where mosquitoes can breed.

The Public Health Agency of Canada (PHAC) notes that less than one percent of human cases develop severe symptoms. The virus was first detected in the region in late August when testing of mosquito pools in Cambridge, Kitchener, and Wilmot Township returned positive results.

Historically, the number of West Nile virus cases in Canada has fluctuated significantly since PHAC began tracking infections in 2003. Annual reports have ranged from a handful of cases to a high of 2,401 cases in 2007. Preliminary data from PHAC indicates that there were 166 cases reported in 2024.

As the community navigates the remainder of the mosquito season, health officials remain vigilant and encourage residents to stay informed and proactive in protecting their health.