Canada Loses Measles Elimination Status After 30 Years

Canada has officially lost its measles elimination status after nearly three decades, following an alarming outbreak that has seen over 5,000 cases reported nationwide. This declaration from the Pan American Health Organization (PAHO) on October 16, 2023, marks the first time since 1998 that Canada is no longer recognized as free from endemic measles, a development that has shocked public health officials and healthcare professionals alike.

Dr. Anne Pham-Huy, chair of Immunize Canada and a pediatric infectious disease specialist at CHEO, expressed her dismay, stating, “To lose this elimination status is devastating in many ways because it is so preventable. It is embarrassing and sad.” Many in the health sector see the loss as a significant setback, particularly for vulnerable populations who depend on herd immunity for protection against measles.

The ongoing outbreak has highlighted vulnerabilities within Canada’s public health system. University of Ottawa epidemiologist Raywat Deonandan described the situation as a wake-up call. “It is not a crisis in the sense an epidemic is at our doorstep but strongly indicative of fragility in our public health system,” he noted. Deonandan and others have called for an increase in vaccination efforts, urging the public to understand the importance of immunization to combat rising vaccine hesitancy.

The announcement from PAHO has sparked renewed discussions about the necessity of establishing a national vaccine registry in Canada. Currently, Canada stands out as the only G7 country lacking such a registry, which serves as a critical tool for tracking vaccination coverage and ensuring public health readiness.

In a statement, the Public Health Agency of Canada confirmed its commitment to collaborating with PAHO and engaging with federal, provincial, territorial, and community partners. The focus will be on enhancing vaccination rates, improving data sharing, and strengthening overall surveillance efforts.

Historically, Canada maintained its measles elimination status due to high vaccination rates. Measles is known to be the most contagious infectious disease, but it is also preventable through effective vaccination. For herd immunity to be effective, a coverage rate of at least 95 percent with two doses of the vaccine is required. However, vaccination rates have declined significantly, particularly since the onset of the COVID-19 pandemic. In Ontario, only approximately 70 percent of seven-year-olds were fully immunized against measles during the 2023-24 period, a marked drop from 86.1 percent in 2019-20.

The sustained transmission of measles for 12 months is considered a key indicator that endemic measles has re-established in a country. The PAHO officials noted that Canada’s loss of elimination status also affects the entire Pan American region. “This loss represents a setback,” said PAHO Director Dr. Jarbas Barbosa. He emphasized that countries like Venezuela and Brazil have previously regained their elimination status after similar challenges. “Elimination remains one of the greatest public health achievements of our region. It is an achievement we can and must recover,” he added.

While outbreaks of measles in the Americas account for less than 8 percent of global cases, the situation remains critical. Public health officials have traced the recent outbreak in Canada, which included nearly 2,400 cases in Ontario alone, to a gathering of Mennonites in New Brunswick last fall. Over 80 percent of the cases have been among unvaccinated individuals, prompting calls for tailored strategies to increase vaccine uptake in these communities.

The situation is compounded by the spread of disinformation regarding vaccines, often exacerbated by online platforms and, at times, even by health officials. Furthermore, public health units in Ontario are facing significant funding challenges, which hinder their ability to effectively monitor and control infectious diseases. Without a reliable vaccination registry, public health staff must manually check vaccination records, making it difficult to track immunization rates accurately.

In Ottawa, officials are currently monitoring several measles cases and have issued warnings about potential exposures at various locations. Additionally, the government of Nunavut has alerted residents to possible risks of exposure when traveling to Ottawa.

To regain its measles elimination status, Canada must now go 12 months without sustained transmission of the disease. As public health agencies work to address vaccination hesitancy and improve immunization coverage, the focus remains on ensuring that Canada does not experience further setbacks in its public health achievements.