COLORADO SPRINGS, Colo. (KXRM)— Top health officials are monitoring the worst mumps in the United States in 10 years.

Harvard University has been dealing with handfuls of infected students since the beginning of the school year and over at the University of Missouri, more than 200 people have come down with the virus.

The CDC says mumps cases have now surfaced in all but four states with nearly 4,300 infections reported.

Several public schools near Seattle have reported a growing number of cases.

Arkansas is the epicenter – with nearly 2,200 cases – in mostly school-aged children.

Mumps is extremely contagious and can be spread with a sneeze or cough.

Doctors say the best way to protect yourself is to get vaccinated.