"Many countries are in the midst of sizeable measles outbreaks, with all regions of the world experiencing sustained rises in cases", WHO further said.
The number of measles cases reported worldwide in the first three months of 2019 has tripled compared with the same time a year ago, according to the World Health Organization (WHO).
In 2014, the United States reported a record 667 cases, including one large outbreak primarily among unvaccinated Amish communities in OH that accounted for more than half of the cases.
In the first quarter of the year, 170 countries reported some 112,000 infections, up from 28,000 in the first quarter of 2018. So far in 2019, there have been 555 measles cases across 20 states.
Measles killed almost 110,000 people in 2017.
Last week, New York City officials declared a public health emergency and ordered mandatory measles vaccinations to halt the outbreak concentrated among ultra-Orthodox Jews in Brooklyn, putting in place the broadest vaccination order in the United States in almost three decades. If the outbreaks aren't brought under control, public health experts worry that the cases in 2019 will hit a record almost two decades after measles's "elimination" in the United States.
A state judge overturned the order, but Rockland is appealing that decision.
While easily preventable with a vaccine, measles is highly contagious and can be unsafe, especially for small children.
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.
NY health officials said they were working with orthodox Jewish leaders to combat anti-vaccination campaigns. However, the claim spread fear among parents, leading to a small but vocal faction that makes up the current anti-vax movement.
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.
Measles can be serious for all age groups, but it is most risky for children under 5 and adults over 70.
Measles is a highly infectious viral illness that can sometimes lead to serious health complications, including infections of the lungs and brain.