The number of measles cases across the USA rose for the third week in a row, bringing the total to 555 - the highest number in the past five years, the Centers for Disease Control and Prevention said Monday.
So far this year, 170 countries have reported 112,163 measles cases to the WHO.
Measles first became a notable disease in the United States in 1921, requiring US health care providers and laboratories to report all diagnosed cases. So far in 2019, there have been 555 measles cases across 20 states.
A sign warning people of measles in the ultra-Orthodox Jewish community of Williamsburg, two days after New York City Mayor Bill de Blasio declared a public health emergency in parts of Brooklyn in response to a measles outbreak, is seen in New York, U.S., April 11, 2019.
Most of the cases have been in NY, site of an outbreak among ultra-Orthodox Jews that started in the fall.
A state judge overturned the order, but Rockland is appealing that decision. Almost two-thirds of all cases have been in NY, and 85% of the latest week's cases came from the state.
While easily preventable with a vaccine, measles is highly contagious and can be risky, especially for small children. The city said those individuals who become infected with measles and chose not to get vaccinated since the mandatory order would be fined $1,000 dollars.
Public health officials say current measles outbreaks in the US are fueled by the anti-vaccination movement, which questions the safety of vaccines and frequently spreads false information on social media. His research was found to be based on fraudulent data, the study was retracted, and the doctor lost his medical license.
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.
The CDC recommends two doses of the measles mumps and rubella, or MMR, vaccine for children.
Video: Despite the massive evidence, the anti-vaccination movement is gaining strength.
Measles is a highly infectious viral illness that can sometimes lead to serious health complications, including infections of the lungs and brain.