Scores more people have fallen ill in the village of Kiryas Joel in Orange County and hundreds are sick in Brooklyn.
Investigators have traced the U.S. outbreak to a Jewish summer camp in Sullivan County, and a boy who unknowingly carried the illness over from England.
Most of the people now being afflicted are in the state's tightly knit communities of Orthodox and Hasidic Jews.
Mumps is spread by coughing and sneezing.
Common symptoms include fever, headache and swollen salivary glands, but it can sometimes lead to more serious problems.