The measles outbreak in the United States continues to spread as individual cases of the contagious respiratory disease has been confirmed in 26 states.

On Monday, the U.S. Centers for Disease Control and Prevention (CDC) reported an additional 60 confirmed individual cases of measles. The total number of measles cases reached 940 in the week ended March 24.

It is the greatest numbers of measles cases recorded in the U.S. since 1994 and since 2000 when federal health officials declared that the disease was eliminated in the country.

Health officials blame misinformation about MMR vaccines for the recurrence of measles outbreak

Public health officials blamed the spread of misinformation regarding vaccines for the recurrence of measles in country. Many parents rejected the MMR vaccine against measles, mumps and rubella because of their false belief that it causes autism. Their belief contradicts scientific studies that the MMR vaccine is proven safe and effective and provides long-lasting protection against measles that has the potential to be deadly.

Prior to the U.S. measles vaccination program that started in 1963, between 3 million and 4 million people were infected with measles annually. Around 400 to 500 of those people died, 48,000 were hospitalized and 1,000 developed encephalitis (swelling of the brain), according to the CDC.

The widespread use of the MMR vaccine in the United States resulted to a 99 percent reduction in measles cases compared before 1963.

The CDC noted the measles outbreak linked to travelers who brought the disease back to the U.S. from countries such as Israel, Ukraine and the Philippines. Currently, large measles outbreaks are happening in these countries.

New York City ordered mandatory MMR vaccination to stop measles outbreak

Last month, the New York City Health Department ordered a mandatory MMR vaccination for unvaccinated individuals living in select areas in Williamsburg. The city’s health officials issued the order to prevent the measles outbreak, which infected hundreds of residents in Brooklyn and Queens. Most of the cases involved members of the Orthodox Jewish community.

A group of parents sued the NYC Health Department alleging that the order doesn’t have sufficient grounds to justify such drastic measure. A judge dismissed the lawsuit citing the reason that the MMR vaccine is necessary due to the “significant spike in incidence of measles across the country.” He noted that the Williamsburg section in Brooklyn is at the epicenter of the measles outbreak.

As of May 24, there have been 535 confirmed cases of measles in Brooklyn and Queens since September.

On Friday, Maine Governor Janet Mills signed into law a bill ending most non-medical exemptions for mandatory vaccines for children. She signed the bill a few days after the first confirmed case of measles was recorded in the state.