National surveillance of Lyme disease, 1987-1988.

In 1987 and 1988, 6876 Lyme disease cases from 43 states were reported to the Centers for Disease Control. The 4507 cases reported in 1988 was nearly double the case number reported in 1987, and ninefold the number reported in 1982, when a systematic system of national surveillance was established. The average annual incidence of reported Lyme disease in the United States in 1987-1988 was 1.4/100,000. New York led the nation in reported cases in 1988 with 57% of the cases reported nationally. Eight states, New York, New Jersey, Pennsylvania, Connecticut, Massachusetts, Rhode Island, Wisconsin, and Minnesota, reported 92% of the nation's cases. The state reporting the highest incidence rate in 1987-88 was Rhode Island, with 9.9 cases/100,000. Regionally, incidence rates were highest in Northeastern and Mid-Atlantic states, intermediate in North Central and Pacific states, lower in the Southeast, and lowest in the Great Plains and Mountains states. The seven remaining states in which Lyme disease has not been transmitted all lie west of the 100th meridian.