The New York City Department of Health and Mental Hygiene is urging all Orthodox Jews who plan to make a trip to Israel to vaccinate their children against the measles virus.

An outbreak of measles believed to be caused by an unvaccinated child who contracted the disease in Israel led to 90 confirmed cases in Brooklyn, N.Y., between October and February 2019, a high number attributed to low vaccination rates in the ultra-Orthodox community.

The neighborhoods primarily affected were Borough Park and Williamsburg, which had 40 cases each.

Israel’s measles outbreak led to the death of two people, including an 18 month-old infant in 2018.