The virus has been spreading for nearly a year in the U.S. — a key factor in determining whether a country loses its measles elimination status.

Canada is no longer measles-free, health authorities have declared, after 5,000 cases were recorded in a year. The country lost its measles elimination status more than one year after the highly contagious virus started spreading,

With nearly 800 cases and rising concern across the Southwest, experts warn the U.S. could lose measles eradication status without higher immunization rates.

The Louisiana Department of Health on Monday reported the state's third measles case of the year and warned that those who were at the New Orleans airport the night before may have been exposed.

A commission in charge of monitoring efforts to eliminate measles from the Americas has decided that the region can no longer be considered free of the highly contagious disease.The decision not to reverify the entire region as being measles-free was based on a large outbreak in Canada that began last October,