(Reuters) – A New York suburb has banned children not vaccinated against measles from public spaces, such as schools and shopping malls, as it fights the state’s worst outbreak in decades of the potentially deadly disease.

Rockland County declared a state of emergency on Tuesday and said the ban would remain in place for 30 days or until unvaccinated children get the measles, mumps and rubella (MMR) shot.

The Rockland announcement follows measles outbreaks in California, Illinois, Texas and Washington and is part of a global resurgence of the viral infection, according to the U.S. Centers for Disease Control and Prevention.

“We will not sit idly by while children in our community are at risk,” County Executive Ed Day said in a statement. “This is a public health crisis, and it is time to sound the alarm.”

There have been 153 confirmed cases of measles in Rockland County, about 11 miles (18 km) north of Manhattan, mostly among children who have not been vaccinated.

The ban begins at midnight after which unvaccinated children will not be permitted in locations such as places of worship, schools and shopping malls. Outdoor spaces like playgrounds are excluded from the ban. People medically unable to get vaccinated are exempt.

The outbreak began when a traveler visited Israel and returned to a predominantly ultra-Orthodox Jewish neighborhood of Rockland County. There have also been at least 181 confirmed cases of measles in the New York boroughs of Brooklyn and Queens since October, mostly among Orthodox Jews, according to the city’s health department.

The New York and Washington outbreaks began after U.S. travelers picked up measles in foreign countries, where the disease was running rampant and brought it back to places where vaccination rates were too low by U.S. public health standards.

The disease has spread mostly among school-age children whose parents declined to get them vaccinated, citing reasons such as philosophical or religious beliefs, or concerns the MMR vaccine could cause autism, authorities said.

Large scientific studies have demonstrated that there is no link between vaccines and autism.

Officials say the measles outbreaks offer a lesson about the importance of maintaining a minimum 95 percent “herd” level of immunization against dangerous, preventable diseases such as measles. Rates as low as 60 percent were found in parts of New York where measles spread, State Health Commissioner Howard Zucker said in February.

(Reporting by Andrew Hay in New Mexico; Editing by Bill Tarrant and Bill Berkrot)