People walk through an ultra-Orthodox Jewish community in Williamsburg on April 10, 2019 in New York City.

Almost 400 people in New York City have contracted measles since the outbreak began in October, according to new data from the New York City Health Department.

Thirty one new cases have been confirmed in the last week, health officials said Wednesday, bringing the city's total to 390 over the last several months. Two pregnant women have also contracted the infection, including one in the past month, city officials said.

Most cases are still coming out of an outbreak in Brooklyn's Williamsburg and Borough Park neighborhoods. Williamsburg, where 323 cases have been reported, is home to a tightly-knit Orthodox Jewish population, where vaccine hestitancy is rising.

"These cases are stark reminders of why New Yorkers must get vaccinated against the measles as soon as possible. When we do not get vaccinated, we put our friends, our relatives, our neighbors, our classmates and other fellow New Yorkers at risk," Health Commissioner Dr. Oxiris Barbot said in a statement.

New York City Mayor Bill de Blasio declared a public health emergency April 9 and ordered all people in certain neighborhoods to get vaccinated or face a $1,000 fine. The city has issued summonses to 12 people for failing to comply with the city's order.

Experts worried the start of Passover this past weekend could increase the risk of spreading measles as families gathered for the eight-day holiday.

"Currently, the outbreak remains intensely focused in Williamsburg where vaccination rates must continue to improve," Deputy Commissioner Dr. Demetre Daskalakis said in a statement.