EPIDEMIOLOGY

Of the total vector-borne illnesses found in the United States, Lyme disease is by far the most prominent; it accounts for more than 95% of the vector borne cases of illness in the United States.[3] Approximately 15,000 cases of Lyme disease are reported annually, though it is believed to be vastly underreported. [4] An estimated 150,000 cases have been reported since 1976.

In the United States, Lyme disease is localized in northeastern, mid-Atlantic and upper north-central states. [5] Though Lyme has been reported in 49 of the 50 states, there are 12 states in which it is particularly prevalent: Connecticut, Delaware, Rhode Island, Maine, Maryland, Massachusetts, Minnesota, New Jersey, New Hampshire, New York, Pennsylvania, and Wisconsin. In endemic areas the incidence of Lyme Disease is as high as 3%.

Lyme disease incidence by county in 2000. (Link)

The insect vectors that spread Lyme Disease, Ixodes Scapularis and Ixodes Pacificus, are most prominent in forested and grassy areas, and their populations are greatest during the the summer months.

Incidence of Lyme disease infection by month. (Link)

Prevalence of Tick populations in by county in 1907-1996. (Link)

Lyme disease is most common in children under 15 and adults between 39 and 59 and has no gender preference. High-risk groups include people who work or spend time outdoors such as: farmers, ranchers, scientific researchers, hikers, trail workers, runners, and vacationers. [6]

Number of new cases of Lyme disease reported from 1991 to 2002. (Link)

The recent increase in deer populations across the country, have increased the number of ticks and therefore the prevalence Lyme disease.