The Pan American Health Organization (PAHO) is urging countries in the Americas to strengthen immunization activities, enhance disease surveillance and rapid response interventions, as measles cases continue to rise in the region. As of 8 August 2025, a total of 10,139 confirmed measles cases and 18 related deaths have been reported across ten countries, representing a 34-fold increase compared to the same period in 2024.

The outbreaks are linked primarily to low vaccination coverage, with 71% of cases occurring in unvaccinated individuals and a further 18% in people whose vaccination status is unknown. In 2024, coverage with the first dose of the measles, mumps, and rubella (MMR) vaccine in the region reached 89% (two percentage points higher than in 2023), while the second dose increased from 76% to 79%. However, these levels remain below the 95% recommended to prevent outbreaks.

“Measles is preventable with two doses of a vaccine, which is proven to be very safe and effective. To stop these outbreaks, countries must urgently strengthen routine immunization and conduct targeted vaccination campaigns in high-risk communities,” said Dr. Daniel Salas, Executive Manager of the Special Program for Comprehensive Immunization at PAHO.

Countries with the highest case numbers include Canada (4,548 cases), Mexico (3,911 cases), and the United States (1,356 cases). Other countries reporting confirmed cases are Bolivia (229), Argentina (35), Belize (34), Brazil (17), Paraguay (4), Peru (4), and Costa Rica (1). Paraguay is the latest country to report an outbreak this year. Deaths have been reported in Mexico (14), the United States (3), and Canada (1). In Mexico most deaths have occurred in indigenous people between 1 and 54 years of age. Canada reported a fatal congenital measles infection in a newborn.

The current outbreaks are associated with two genotypes of the measles virus. One genotype has been identified in outbreaks across eight countries, particularly among Mennonite communities in Canada, the United States, Mexico, Belize, Argentina, Bolivia, Brazil, and Paraguay. Given that measles is a highly contagious viral disease, it spreads rapidly among unvaccinated populations, especially children. However, recent data suggests an increasing number of cases outside of these groups.

Countries highlights

• In Canada, national trends shows that transmission is persisting, particularly in Alberta, British Columbia, Manitoba, and Ontario, following an outbreak that began in New Brunswick in October 2024.
• In Mexico, a mass vaccination campaign targeting people aged 6 months to 49 years is underway in 14 priority municipalities that have active measles transmission in Chihuahua, which accounts for 93% of the country’s cases. Indigenous communities have been hardest hit, with a case-fatality rate 20 times higher than in the general population.
• The United States has reported outbreaks in 41 jurisdictions, mainly among under-vaccinated Mennonite populations, though no new cases have been reported in Texas or New Mexico since late July.
• In Bolivia, most cases are concentrated in Santa Cruz, with additional cases reported in seven other departments, affecting both the general population and Mennonite communities.
• Argentina and Belize have seen no new cases since late June.
• Brazil has reported 16 cases in Tocantins, linked to the regional outbreak and affecting members of a small Russian Orthodox community.

PAHO response and recommendations

PAHO is providing direct technical cooperation across the region to support surveillance, case investigation, outbreak response, laboratory diagnostics, and vaccination efforts. This includes deploying experts to countries such as Mexico, Argentina, and Bolivia; monitoring importation risks in Brazil and Paraguay; strengthening surveillance systems; and working with communities and health workers to counter misinformation and promote vaccine uptake.

The Organization urges countries to:

• Achieve and sustain high immunization coverage (at least 95% with two doses of measles-containing vaccine),
• reinforce rapid response systems to contain outbreaks quickly,
• scale up vaccination strategies from selective approaches (such as ring or mop-up vaccination) to mass campaigns in outbreak and high-risk areas, based on the epidemiological situation and population movement.
• ensure timely detection and laboratory confirmation of cases,
• and engage at-risk communities to improve health literacy and address vaccine hesitancy.

PAHO does not recommend travel restrictions but advises travelers to ensure they are vaccinated, especially when visiting areas with active outbreaks. This includes children aged 6 to 11 months, who are not usually covered by routine immunization programs but should receive early protection in outbreak contexts.

Regional and global context

The Americas interrupted endemic transmission of measles in 2016, a milestone unique at the global level. Although endemic transmission reappeared in Venezuela and Brazil in 2018 and 2019, both countries regained their elimination status in 2023 and 2024, respectively. However, keeping measles at bay in the Americas remains a challenge, as the virus continues to circulate widely in other parts of the world and vaccine-hesitant groups are spread throughout the region.

Globally, surveillance data from the World Health Organization (WHO) has recorded 239,816 suspected cases and 108,074 confirmed cases in all WHO Regions, as of July 2025. The Eastern Mediterranean Region accounts for the highest share (35%), followed by the African Region (21%) and the European Region (21%).