NEW YORK – The geographic areas where Lyme disease is a bigger danger have grown dramatically, according to a new government study published Wednesday. U.S. cases remain concentrated in the Northeast and upper Midwest. But now more areas in those regions are considered high risk. “The risk is expanding, in all directions,” said the lead author, Kiersten Kugeler of the Centers for Disease Control and Prevention. There are now 260 counties where the number of Lyme disease cases is at least twice what’s expected, given the size of each county’s population.