Lyme Disease

Abstract

Over the past 20 years since Lyme disease was first diagnosed, it has been identified as the most common vector-borne disease in the United States. The repopulation of white-tailed deer in the United States has been associated with the emergence of this disease. The tick vector, Ixodes scapularis, harbors Borrelia burgdorferi (B.b.), the organism responsible for Lyme disease.² The larval and nymphal stages feed on intermediate hosts, which are mostly small mammals and birds. Occasionally they will feed on carnivores such as dogs and humans. The adult tick prefers to feed on deer, but will also feed on dogs and people. The main intermediate host in the northeastern United States is the white-footed mouse. In the Midwest, however, it has been determined that the eastern chipmunk may be equally important as an intermediate host. The ticks appear to follow the migration of deer. Deer appear to be only an amplification host for the tick population since they are able to clear infection from B.b. within a few days. Mice and chipmunks may serve as reservoirs for B.b. in nature since they maintain active infections for at least 3 to 4 months.

The best laid schemes o’ Mice an’ Men,/Gang aft agley. —Robert Burns, To a Mouse

Thanks to M. Roberto Cortinas for helping develop the model of this chapter.