Higher rates of the preventable but highly contagious disease, which can kill a child or leave it disabled for life, have been recorded in all regions, the United Nations agency said in a statement. Last month, Rockland County, a New York City suburb that's confirmed 184 cases so far this year, issued an emergency order banning unvaccinated children from public places.
The number of confirmed cases of measles in the United States this year jumped by almost 20 percent in the week ended April 11, in the country's second-worst outbreak in almost two decades, federal health officials reported on Monday.
A spike in case numbers was, in addition, reported for countries including the U.S. and Thailand with high levels of vaccination coverage.
The states that have reported measles cases to the CDC include Arizona, California, Colorado, Connecticut, Florida, Georgia, Illinois, Indiana, Kentucky, Maryland, Massachusetts, Michigan, Missouri, Nevada, New Hampshire, New Jersey, New York, Oregon, Texas and Washington, bringing the total number of U.S. states affected to 20.
The CDC recommends two doses of the measles mumps and rubella, or MMR, vaccine for children.
It said the number of measles cases worldwide rose to 112,163 against the same period past year, citing provisional data.
Experts say overall vaccination rates of 90 to 95 percent are needed to provide "herd immunity", which helps keep outbreaks at bay and protect babies who are too young to be vaccinated and others who can't get the vaccine for medical reasons.
Most of the cases have been in NY, site of an outbreak among ultra-Orthodox Jews that started in the fall. However, the claim spread fear among parents, leading to a small but vocal faction that makes up the current anti-vax movement. According to the CDC, there was an average of 6,000 measles-related deaths each year within the first decade of the disease being reported.
Measles can be an extremely serious disease.
In an opinion piece for CNN, WHO heads Henrietta Fore and Tedros Adhanom Ghebreyesus said the world was "in the middle of a measles crisis" and that "the proliferation of confusing and contradictory information" about vaccines was partly to blame. "When measles was rampant before the vaccines were available, it was one of the most devastating diseases globally and in the United States".
About 1 out of every 1,000 children who gets measles will develop encephalitis or swelling of the brain, according to the CDC.
Health officials there announced last week that in the neighborhoods affected by the outbreak, anyone who has not had been vaccinated against measles or cannot show evidence of immunity could face a $1,000 fine. The Ukraine has recorded about 37,000 cases this year.