DEER, TICKS, and LYME DISEASE Deer Management as a Strategy for the Reduction of Lyme Disease

In Connecticut and the northeastern United States, the blacklegged tick, Ixodes scapularis (commonly known as the deer tick) is the vector for four disease agents; Borrelia burgdorferi, Anaplasma phagocytophilum, Babesia microti, and the deer tick virus (DTV) that cause Lyme disease, human granulocytic anaplasmosis, human babesiosis, and Powassan encephalitis, respectively. There are around 3,000 human cases of Lyme disease reported in Connecticut each year, which likely represents only about 10% of physician-diagnosed cases. Surveys have found that up to a quarter of residents in Lyme disease endemic areas have been diagnosed with the disease and that many residents perceive the disease as a serious or very serious problem. Managing or treating white-tailed deer, Odocoileus virginianus, the principal host for adult blacklegged ticks, has been studied as a method for controlling tick abundance since the mid-1980s after Lyme disease was recognized from a cluster of cases in Lyme, Connecticut in 1975. Overabundance of deer has been linked to a number of safety, environmental, and agricultural issues, but Lyme disease and other tick-borne illnesses has been the primary motive for the call to manage or reduce deer populations. This fact sheet will explain the tick-host relationship and why deer reduction has been examined as a method to manage tick abundance and tick-borne diseases.