Maine health officials have been sounding the alarm about the spread of COVID-19 in York County in recent weeks, saying the state could lose its grip on the disease if cases continue to grow in Maine’s southernmost county. State data over the past month tell the story of the virus’ accelerating spread in York County, which has been responsible for about 40 percent of the state’s new virus cases since mid-August, even though it’s home to only 15 percent of the state’s population.