Measles Outbreaks Spread Across North America in Canada, Mexico, and the United States

In recent months, North America has experienced a significant resurgence of measles outbreaks impacting Canada, Mexico, and the United States. The situation highlights ongoing challenges in controlling this highly contagious disease despite the availability of effective vaccines. The outbreaks began in Ontario, Canada, in the fall, with cases rising sharply in late January in Texas and New Mexico. Since then, the number of cases has continued to grow, particularly in Chihuahua state, Mexico, with over 786 confirmed cases since mid-February. These regions host communities with notable Mennonite populations, whose historical migration patterns across Canada, Mexico, and Texas have been linked to the spread of the virus.

In Texas, the city of El Paso has seen its highest measles case count outside West Texas, with 38 reported cases, a number that has grown due to the extensive cross-border movement with Mexico. Neighboring Ciudad Juarez has also reported 14 cases. The early cases in El Paso originated from a child at Fort Bliss, and unexpectedly, many cases are among adults. Public health officials have responded with free vaccination clinics, emphasizing the importance of immunization, as many cases are linked to unvaccinated or under-vaccinated populations.

The outbreaks are not confined to specific regions; they are part of a broader pattern seen across North and South America. More than 2,500 cases have been confirmed across the continent, resulting in fatalities—three in the US and one in Mexico. Experts warn that the virus’s genetic strains in Canada match those found in other parts of the continent, indicating that international travel continues to play a significant role in the spread.

The persistent challenge remains the low vaccination coverage in some areas, failing to meet the 95% vaccination threshold necessary for herd immunity. The World Health Organization reports an elevenfold increase in measles activity in the Americas compared to last year, with the risk level now deemed "high." Countries like Argentina, Belize, Brazil, Canada, Mexico, and the US are actively investigating and managing cases, which can be costly—estimated at $30,000 to $50,000 per case in the US.

Border regions, particularly between the US and Mexico and between Canada and the US, are focal points for the outbreak. Health authorities continue to coordinate, with vaccination efforts in border communities, awareness campaigns, and surveillance to contain the spread. The situation underscores the critical need for improved vaccination coverage and robust public health responses to prevent further outbreaks.

Source: https://medicalxpress.com/news/2025-05-measles-borders-north-america-outbreaks.html