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Reflects distribution of Ixodes ricinus complex ticks Lyme disease
North America, Europe, Asia
U.S. Distribution
Most frequently reported vector-borne disease
Three principle region: 11,603 cases reported to CDC Lyme disease, lyme's disease, lime disease in 43 states and D.C. Overall 4.4 cases/100,000
CT, RI, NY, N J, PA, MD, WI, MN account for 92% of cases. Connecticut accounts for MN - 5.8 cases/100,000. Nantucket County, MA - 838.8 cases/100,000
U.S. Distribution
51% males
0 -14 years: 24%
35 - 49 years: 24%
Incidence steadily increasing from 1982 -1994
Increased recognition, increased reporting, true increase in incidence
Drop in incidence from 2006 to 2006
Decreased tick population because of environmental factors
Decreased reporting of non-Lyme disease from GA and MO
Lyme disease Lyme disease
Borrelia burgdorferi
Large spirochete, gram-negative, cell structure and motility is similar to other spirochetes, microaerophilic, can be grown on media; can be visualized with staining in histopathologic sections; can be visualized with light microscope,
Three genomic groups
Borrelia burgdorferi -- all North American cases, European Lyme disease arthritis
B. garinii - Bannwarth's syndrome (tick-borne meningopolyneuritis)
B. afzelii. Acrodermatitis chronica atrophicans
Lyme disease
Vector
· Ixodes ricinus complex ticks
· 3 Stages - larva, nymph, adult; each feeds once on a different
host; life cycle span of 2 years.
· Humans most often infected from