The city Health Department says three new cases of measles have been discovered in the city.
They now say 19 people, including nine children, have contracted the highly contagious disease.
They range in age from three months to 63 years.
Five of them have been hospitalized.
Measles symptoms include a rash, high fever, coughing, red eyes and a runny nose.
It typically lasts five to six days, but in some cases can be fatal.
The Health Department says the outbreak is centered in northern Manhattan but residents of the Bronx and Brooklyn have also been affected.
Health officials are urging New Yorkers to protect themselves by getting vaccinated.