Laboratory Testing for Tick-Borne Infections in a Large Northeastern Academic Medical Center: An 11-Year Experience.
We evaluated changes in the testing menu, volume, and positivity rates for tick-borne illnesses in a New England medical center over an 11-year time frame. Testing data were obtained by a retrospective review utilizing searchable data from a laboratory information system archive. Testing for tick-borne infections (TBI) increased 5.3-fold over an 11-year time period and the number of positive test results increased threefold. Annual rates for Lyme serology positivity varied from 14% to 29% and for western blot confirmation from 26% to 48%. Test volumes and the number of positive results increased for all TBI endemic to our region. Our results confirm national trends suggesting increasing rates of TBI and substantially increased testing. This may reflect a greater incidence of TBI in our region and/or increased awareness of these infections.