Large outbreaks of measles are ongoing in both the United States and Canada.

A total of 164 cases have been notified across 9 jurisdictions of the United States (for 2025, to February 27th). Texas has the highest number of cases (> 100).

According to CDC, 95% of cases were unvaccinated or unknown and more than 50% were in age groups known to have more serious side effects (under 5 years and over 20 years). Twenty percent were hospitalized for either isolation or for medical complications attributed to measles. There has been 1 death.

The number of imported cases contributing to the outbreak has not been reported.

In 2024, 285 measles cases were reported to CDC.

In Canada, 106 cases have been reported in 2025, to February 15th. Most cases come from Ontario (69) and Quebec (20). Of the verified cases (96), 83% were unvaccinated or unknown. Ten cases were under 12 months of age. Four cases were exposed outside Canada (Cambodia, Pakistan, Romania and Vietnam).

In 2024, there were 147 cases of measles and one death.

What outbreaks in these countries tell us

Outbreak news is very important for travel medicine providers, but we must also consider both Canada and the United States are countries with excellent disease surveillance systems. What they are reporting must be happening in many other international destinations.

Measles-Free status and the role of importation

Canada and the United States were declared “free” of measles in 1998 and 2000 respectively. This means that cases only arise from the importation of the disease. While non travel cases occur, they can be linked back to an exposure of a case from overseas.

Australia's Measles-Free Status and COVID-19 Impact

Australia was declared “free” of measles in 2014. Cases result from importation of the disease.

No cases of measles were reported for the year 2021, a period of COVID-19 restrictions when our international borders were closed.

Preventable Cases in Returning Travellers

Researchers from CDC investigated all measles cases in the USA over a 16-year period from 2001 to 2016. They found that 553 cases were imported out of a total of 2098 confirmed cases.

Of these, 344 were returned residents. An analysis of this group found that over 90% of the cases were preventable if CDC vaccination recommendations for travellers were followed. Preventing the importation of measles in returning residents is therefore possible.

Measles Vaccine Recommendations for Travellers

Measles vaccine should be considered in all travellers:

• Who are unvaccinated or have had just one dose
• Who are aged between 6 and 12 months and have not had a first dose
• Who are born between 1966 and 1980 (presumably had 1 dose)

The destination is largely irrelevant given the surge in cases internationally.