Comparison of Lyme Disease in the United States and Europe

Abstract

Lyme disease, or Lyme borreliosis, is the most common tickborne disease in the United States and Europe. In both locations, Ixodes species ticks transmit the Borrelia burgdorferi sensu lato bacteria species responsible for causing the infection. The diversity of Borrelia species that cause human infection is greater in Europe; the 2 B. burgdorferi s.l. species collectively responsible for most infections in Europe, B. afzelii and B. garinii, are not found in the United States, where most infections are caused by B. burgdorferi sensu stricto. Strain differences seem to explain some of the variation in the clinical manifestations of Lyme disease, which are both minor and substantive, between the United States and Europe. Future studies should attempt to delineate the specific virulence factors of the different species of B. burgdorferi s.l. responsible for these variations in clinical features.

Keywords: Borrelia burgdorferi; Borrelia burgdorferi group; Europe; Lyme borreliosis; Lyme disease; Lyme disease spirochete; United States; bacteria; tick-borne diseases; vector-borne infections.

Figure 1

Erythema migrans skin lesions from patients in Europe (A, B) and the United States (C, D).

Figure 2

Southern tick-associated rash illness skin lesions. Adapted from Centers for Disease Control and Prevention, National Center for Emerging and Zoonotic Infectious Diseases, Division of Vector-Borne Diseases.

Figure 3

A) Borrelial lymphocytoma on nipple, showing local swelling and a remnant of erythema migrans on chest; at the time of diagnosis, the lesions had been noticed for 6 weeks. B) Acrodermatitis chronica atrophicans involving the right hand, showing red-purple discoloration, swelling, and skin atrophy; at the time of diagnosis, the lesions had been noticed for ≈2.5 years.

Figure 4

Standard 2-tier and modified 2-tier algorithms for serodiagnosis of Lyme disease. The US Centers for Disease Control and Prevention recommended a standard 2-tier algorithm (A) and the modified 2-tier algorithm (B). *For patients with signs or symptoms consistent with Lyme disease for <30 days, the provider may treat and follow up with a convalescent-phase serum sample. Patients with erythema migrans should receive treatment on the basis of the clinical diagnosis. WB, Western blot.