Those infected could develop symptoms as late as January 23.
Public health officials are warning that people who were in Newark Liberty International Airport on January 2 may have been exposed to the measles.
The New Jersey Department of Health said a woman with an infectious case of measles arrived at the airport that day on an international flight, and later flew to Indianapolis.
Anyone who was at the airport between 6:30 a.m. and 5:30 p.m. "may have been exposed to measles, and if infected could develop symptoms as late as January 23," the department said in a statement.
Measles symptoms include rash, high fever, cough, runny nose and red, watery eyes.
The infected woman is a student at Indiana University. The school issued an advisory to students and staff on Wednesday about their potential exposure.
