The Texas Department of Health said a person with mumps attended the National Cheerleaders Association All-Star National Championship in Dallas, and may have exposed children to the viral illness.
Health officials said children could be infected with the mumps and not even know they are sick.
The health department said most people develop symptoms two weeks after contracting the virus.
In some cases, you won't even know you are sick until a month later.
Competitors from 29 states were present at the NCA competition in Dallas.
What are mumps? Signs and symptoms