The Centers for Disease Control and Prevention is reporting an increase of more than 300 cases of the mumps in April.
The CDC reported 736 cases of the mumps across the U.S. as of April 26, 2019. 436 cases were reported at the end of March.
Cases have been reported in 41 states, including in Mississippi.
2,251 cases of the mumps were reported last year in the United States.
The virus is spread through saliva and mucus.
The CDC says a vaccine is the best defense from the virus.