Measles Is Returning to the Americas

The World Health Organization’s International Committee of Experts declared the Americas free of measles transmission in 2016 after 22 years of mass vaccination. However, in 2017, 4 countries in the region reported cases of measles: Argentina, Canada, the United States and Venezuela. So far this year, 9 countries have registered cases of measles, many of whom were travellers returning from countries where measles is still being transmitted. The affected countries include Antigua and Barbuda, Brazil, Canada, Colombia, the United States, Guatemala, Mexico, Peru and Venezuela. Infected travellers have caused local cases. In Brazil and Colombia, all of their local cases originated from Venezuelan travellers.

Advice

In the countries noted in this alert, there is a risk of further spread of measles due to the failure of national vaccination programs and, in some cases, anti-vaccination resistance in some segments of the population. Sporadic cases and outbreaks are often reported by many countries. All travellers are reminded that outbreaks of the highly contagious measles virus can occur anywhere in the world at any time. Travellers who have not been immunized may be at high risk. Travellers can reduce their risk of exposure to the highly contagious measles virus by ensuring that their childhood vaccinations, including measles, are up-to-date prior to travelling.