Fifteen measles cases — mostly in school-aged children — have been confirmed in a small county in West Texas with one of the highest rates of vaccine exemptions in the state. Some of the cases appear to be connected to private religious schools in the district, said Holbrooks, who cautioned that the investigation is ongoing.

After two measles cases were identified in Houston; an outbreak has been reported in West Texas. Doctors say it's a concerning trend.

A measles outbreak is growing in a Texas county with dangerously low vaccination rates. In late January, two school-age children from Gaines County were hospitalized with measles. Since an estimated 1 in 5 people with the disease end up in the hospital, the two cases suggested a larger outbreak.

It's the latest outbreak of a disease that had been virtually eliminated in the U.S., and it comes as vaccination rates are declining — jeopardizing the country's herd immunity from widespread outbreaks.

A measles outbreak is growing in a rural area of West Texas where vaccination rates are well below the recommended level.

Texas Health and Human Services reports that seven children have been hospitalized with the disease. All were unvaccinated.