Hochul's administration said the emergency declaration was driven by a growing number of cases across rural areas of New York and neighbouring states, including Pennsylvania, which has recorded over 1,000 cases this year with five deaths and 198 hospitalisations. Ohio has also reported an increase. All three states have sizable Amish populations, which tend to be undervaccinated, a factor public health officials say is driving the spread of a disease that had been declared eliminated in the US in 2000.
Of New York's 108 cases, 101 have been reported outside New York City. Since 15 July, 92 cases have occurred in underimmunised rural communities. Nationwide, nearly 3,900 measles cases have been reported, the highest since 1991, according to the Centers for Disease Control and Prevention.
"No one should get seriously ill or die from a vaccine-preventable disease," Hochul said in a statement. "These emergency measures will protect New Yorkers and support our community partners as they work tirelessly to address the spread of this disease."
The outbreak has drawn attention to the Trump administration's health secretary, Robert F Kennedy Jr, a prominent former anti-vaccine activist who headlined an anti-vaccine conference in Washington in September as cases surged. Pennsylvania Governor Josh Shapiro has called Kennedy "incompetent", and the two have clashed over how to classify measles-related deaths.