Lyme Disease Consultations at a Mid-Atlantic Referral Center, 2000-2013

Background: Lyme disease is a serious disease, causing more than 36,000 confirmed and probable cases in the United States annually.  However, many patients diagnosed with Lyme disease do not meet traditional diagnostic criteria.  Previous studies have shown that many patients referred to infectious disease specialists for Lyme disease (LD) did not have Borrelia burgdorferi (Bb) infection.  We compared characteristics of patients as to whether they had illness compatible with LD.

Methods: We retrospectively reviewed 654 patients referred between 2000 and 2013 for a presumptive diagnosis or concern for LD.  Persons age 12 or greater were included.  Subjective symptoms, laboratory tests, treatment at other facilities, and final diagnosis at our facility were abstracted from medical charts.  Diagnosis of LD followed CDC criteria.

Results: Of the total 654 patients, 181/654 (27.7%: 71 active LD, 81 prior LD, and 29 post treatment Lyme syndrome) met criteria for Lyme disease.  The 71 active LD were categorized as 24 early localized LD, 25 early disseminated LD, 17 late disseminated LD, and 5 persistent Lyme arthritis.  463/654 (70.8%) appeared not to have LD, and 10/654 (1.53%) were diagnosed with possible LD.  Patients with symptoms more than 6 months (OR = 0.26, [95% CI: 0.18-0.39]), those who have previously received 3 or more anti-infective medications  (OR = 0.52, [CI: 0.31-0.85]), patients who have received these medications for more than 6 months (OR = 0.17, [CI: 0.07-0.45]), those who have been diagnosed with tickborne co-infections (OR = 0.19, [CI: 0.08-0.48]), and female gender (OR = 0.51, [CI: 0.36-0.71]) are significantly less associated with having LD.  In 495 patients referred for symptoms greater than 6 months, 360/495 (72.7%) had neither serologic nor objective clinical evidence implicating Bb infection. For these 360 patients without evidence of LD, 313/360 (86.9%) have previously received treatment for LD. 

Conclusion: For a referred population to an academic medical center for consideration of LD, symptom duration of more than 6 months, previous use of more than 2 anti-infective medications, duration of therapy over 6 months, history of co-infection, and female gender are less likely to suggest LD.  A significant number of patients without evidence of LD received unneeded anti-infective therapy.