North America
Continent comprising Canada, the United States, Mexico, Central America and the Caribbean.
H5N1 bird flu returned to Canadian poultry in September 2026, one of three live outbreaks across North America that autumn, alongside measles in the United States and Mexico and human screwworm spreading north through Mexico.
Last refreshed: 4 October 2026
Timeline for North America
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Pandemics and BiosecurityBackground
Three outbreaks define North America's 2026 health picture. The Pan American Health Organization counted 3,471 measles cases in the United States and 12,943 in Mexico by 19 September. Mexico recorded 575 human New World screwworm cases to 18 September as the fly moved north. In September H5N1 bird flu outbreaks resumed in Canadian poultry, alongside new outbreaks in France, Sweden and Bulgaria.
North America is the continent of Canada, the United States and Mexico, with Central America and the Caribbean usually counted in it.
The continent has also produced one of the most closely studied human H5N1 cases. A British Columbia teenager was critically ill with the virus in November 2024. A Nature Communications study led by Sriram Subramaniam of the University of British Columbia, reported on 28 September 2026, found two mutations in the teenager's virus that weakened its binding to both human-type and bird-type receptors.
H5N1 returns to Canadian poultry
Poultry outbreaks of H5N1 resumed in Canada in September 2026, alongside France, Sweden and Bulgaria, as the northern autumn season began. Mammal outbreaks across the Americas had fallen by 64.8% on the previous year by mid-July 2026, PAHO said. North America recorded none of the 11 human H5N1 infections logged worldwide in 2026 up to 1 October, according to Hong Kong's Centre for Health Protection.
North America's main contribution to the 2026 Science came from British Columbia. Researchers under Sriram Subramaniam at the University of British Columbia reported in Nature Communications on 28 September 2026 that two mutations in a critically ill teenager's November 2024 virus weakened its grip on human-type and bird-type receptors alike.