OCHCA confirmed that she is considered infectious between April 23 and May 1.
The New Jersey Department of Health says a New York City resident with a confirmed case of the virus may have exposed other people in Middlesex and Ocean counties, CBS New York reports.
The woman, who had just returned from an worldwide trip, didn't know she had the very contagious virus.
The U.S.is now experiencing the highest number of measles cases since 1994, with more than 700 cases confirmed across the nation as of Monday, according to the Centers for Disease Control and Prevention.
Although this is the first case confirmed in Orange County this year, an increase in incidents has been reported across the United States and the globe.
The patient is now under voluntary isolation inside her home, authorities said. "And of the nine jurisdictions now experiencing outbreaks in the United States, three of them are in California-and the disease has turned up in 11 counties so far".
Avengers: Endgame had the a historic opening at the box office - with $350 million in North America - and people flocked to theaters to see it.
Measles is highly contagious and can cause complications, especially for young children and adults.
In California, 14 of 38 people with measles this year became sick while visiting other countries, including India, Thailand, the Philippines, Vietnam, Cambodia and the Ukraine, according to state health officials.
An Allegheny County resident - an unvaccinated adult who recently traveled overseas - was treated for measles Monday in UPMC Shadyside's emergency room and is recovering at home.
People who haven't been vaccinated and those with weakened immune systems are at the highest risk.