Why the US, Mexico and Guatemala may lose their measles-free status

A independent commission is meeting to review whether countries in the Americas still meet its measles elimination criteria. International health experts are meeting in Washington, DC, this week to determine which countries in the Americas have endemic measles transmission. The outcome could decide whether the United States, Mexico and Guatemala retain their “measles elimination status”: a designation that the virus has not spread uncontrolled domestically for at least 12 months.

The Pan American Health Organization’s (PAHO) Regional Monitoring and Re-Verification Commission (RVC) began its annual conference on Tuesday to assess the countries’ status. The conference will adjourn on Friday. The review comes as a sharp resurgence of the virus has spread across the Americas, with the US experiencing its largest and deadliest measles outbreak in nearly 30 years.

The US has held its elimination status since 2000, but it risks losing it this year.