The Lexington-Fayette County Health Department says the four cases are linked to a previous outbreak in Woodford and Fayette counties, but there is no known additional risk to the public.
For now, Kentucky's total number of measles cases this year stands at 11 — a far cry from the hundreds recorded in the hardest hit state, Texas.
But health officials warn a national snapshot of the outbreaks shows the country at its peak since 2000.
We had declared eliminated measles in The United States twenty five years ago. We've now had more than twelve hundred cases in the United States this year alone," Cabinet for Health and Family Services Secretary Steven Stack. "It's going to get hard real soon to be able to claim anymore that it's eliminated in the United States."
The CDC defines an outbreak as three or more related cases.
Although the numbers may sound small in Kentucky so far, health officials warn that declining vaccination rates and the highly contagious nature of the illness make for a worrying combination.