New Delhi, Feb. 10 -- Mexico's most populous state said Monday it was stepping up health screening at schools and recommended the use of face masks for students and staff as the country confronts a growing measles outbreak.

The decision by Mexico state followed similar measures announced last week in the western state of Jalisco, site of the country's largest outbreak, where masks are now required in the schools of its capital Guadalajara, Mexico's second-largest city.

Through Feb. 6, there were 2,143 confirmed measles cases nationwide and nearly 6,000 suspected cases. Jalisco was home to more than half of Mexico's confirmed cases, but there are confirmed cases from Mexico's northern border to its southern border.

The health department...