Canadian health authorities report a sharp surge in influenza activity, with hospitalizations nearly doubling and overall case numbers rising by almost 30 per cent in the latest available data. The escalating situation, driven predominantly by the influenza A(H3N2) strain, particularly impacts the youngest and oldest demographics across the country, placing increasing strain on healthcare systems.

For the week ending December 13, Canada recorded 11,646 new influenza cases, reflecting a positivity rate of 27.7 per cent among all tests conducted. This marked a significant 71 per cent increase from the previous week, which saw 6,799 new cases and a positivity rate of 20.2 per cent, indicating a rapidly accelerating spread of the virus nationwide.

The rate of influenza-related hospitalizations climbed to 6.2 people per 100,000 population during this period, a substantial rise from 3.6 per 100,000 in the preceding week. Concurrently, the number of reported outbreaks across Canada more than doubled, soaring from 91 in the first week of December to 186 by the week ending December 13.

Influenza activity is now widespread, with 44 regions across 11 provinces and territories reporting increased viral circulation. Health Canada issued a statement confirming that “all indicators of influenza activity are high and increasing,” with every region throughout the country observing heightened levels of the illness.

The demographics most severely affected by the current influenza wave are adults aged 65 years and over, alongside children aged four years and younger, who exhibit the highest rates of weekly hospitalizations. Data further reveals that 44 per cent of the newly detected cases occurred in individuals aged 19 years or younger, underscoring the significant impact on pediatric and adolescent populations.

The World Health Organization identifies the influenza A(H3N2) strain, including a subvariant known as A(H3N2) subclade K, as the dominant strain circulating in both Canada and the United States. This particular strain is often associated with more severe outcomes, especially in vulnerable groups.

In Ottawa, the severity of the outbreak has been tragically highlighted by the deaths of three children, aged between five and nine years, due to influenza A-related complications. Local health officials are urgently advocating for all individuals over six months of age to receive their influenza vaccination as a critical preventative measure.

Children’s hospitals are particularly affected by the surge. The Children’s Hospital of Eastern Ontario (CHEO) reported an eight-fold increase in children testing positive for influenza in November compared to the same month last year, alongside a doubling of pediatric hospitalizations. CHEO officials emphasized the heightened risk for children under five, whose smaller airways and developing immune systems make them more susceptible to severe illness, noting the rapid spread in schools and childcare settings.

Across the country, emergency rooms are grappling with an influx of influenza patients. In Alberta, for instance, hospital emergency departments are experiencing a significant surge, with provincial case numbers jumping 70 per cent in a single week. This rapid increase strains healthcare resources and underscores the broader public health challenge posed by the current flu season.

The pronounced increase in flu cases and hospitalizations serves as a critical reminder of influenza’s potential severity, extending beyond that of a common cold. Public health authorities continue to monitor the situation closely and reinforce calls for vaccination, hand hygiene, and staying home when ill to mitigate transmission and protect vulnerable populations from severe outcomes.

Read Original