April 15 — The U.S. Centers for Disease Control and Prevention (CDC) on Monday reported a nearly 20 percent jump in the number of people confirmed with measles in the week since April 4.

From Jan. 1 to April 11, 555 individual cases of measles have been confirmed in 20 states, the second-highest number of cases reported in the United States since the disease was declared eliminated in 2000, the health agency said.

The CDC had reported 465 cases in 19 states between Jan. 1 and April 4.

In New York City there have been at least 285 reported cases of measles since October, the large majority among members of the Orthodox Jewish communities in Brooklyn. Mayor Bill de Blasio declared the outbreak a public health emergency last week and ordered unvaccinated people in the affected parts of Brooklyn to get the vaccine or face a fine.