Forty years ago Lyme Disease didn't even have a name. Today, the tick-borne disease infects up to 300,000 people each year and has greatly expanded its range beyond the small Connecticut town where it was first identified in 1975. While the data doesn't go that far back, the numbers from the last 15 years paint a disconcerting picture of a disease on the rise.

The story of the growth of Lyme Disease is really the story of the deer tick, the primary vector for the disease and the beneficiary of a warming climate and increasingly fragmented forests. Where the deer tick and its small mammal hosts are found, so too is Lyme Disease.

NOTE: The below data represents only the reported cases, which the CDC estimates could be as few as 10 percent of all infections. For more information on this data, see this CDC explanation.