Canada has officially reverted to experiencing endemic measles, marking a significant setback in public health efforts. The Pan American Health Organization (PAHO) announced this week that the country no longer maintains its measles elimination status, a milestone it achieved in 1998.

This change follows a thorough review by PAHO experts, who analyzed recent outbreak data and transmission patterns across the Americas. Canada now joins the US and Mexico, where measles transmission is also resuming, reflecting growing challenges in maintaining vaccination coverage.

Measles is considered eliminated when no continuous local transmission occurs for 12 months. However, sporadic imported cases can still trigger limited outbreaks. Endemic status is declared when the virus sustains transmission over a full year, as is now the case in Canada.

Experts warn that declining vaccination rates and vaccine hesitancy contribute to the resurgence of measles. According to the World Health Organization, maintaining high immunization coverage—above 95%—is crucial to prevent the virus from becoming endemic again.

David Nield

Dave is a freelance tech journalist with over 20 years covering gadgets, apps, and the web. From Stockport, England, he covers news, features, and reviews for TechRadar, focusing on phones, tablets, and wearables. He ensures top weekend breaking news and has bylines at Gizmodo, T3, PopSci, and others. He edited PC Explorer and The Hardware Handbook for years. Read me on x.com or linkedin.