Thirteen cases of mumps have now been confirmed at the State University of New York at New Paltz.
The Daily Freeman of Kingston reports that the 13 cases include one athletics staff member at the Hudson Valley school and several swim team members.
County health officials learned of the outbreak a month ago.
The affected students, who have been immunized against mumps, have been isolated for the recommended period of time.
Twenty students who have not been immunized have been sent home until December.