The 19 "blue states" those won by Senator John Kerry account for 95 percent of the cases of Lyme disease reported in 2002, they wrote. The disease, caused by bacteria that are carried by deer ticks, is concentrated in the Northeast and Midwest states.

An accompanying letter, from Robert Nadelman and Gary Wormser, epidemiologists at the New York Medical College at Valhalla, also pointed out that many of the cases reported in "red states" were probably something else. The illness there is usually preceded by the bite of the Lone Star tick, which cannot transmit the bacteria that causes Lyme disease, although it produces a rash that is identical. The two doctors suggest naming the disorder Stari, for southern tick-associated rash illness. Lyme disease is spreading faster than Stari, Nadelman said. The last three Democrats elected to the White House were from states where Stari is dominant, while three of the four most recent losing candidates came from Lyme disease states.