What You Thought You Knew about Borrelia and Borreliosis

摘要

Lyme borreliosis, commonly called Lyme disease, is an infectious disease caused by the spiro-chete Borrelia burgdorferi.1 Its reservoirs in nature are different species of rodents, which may harbor a large number of organisms without apparent ill effects. The vector tick, Ixodes scapularis, commonly called the black-legged or deer tick, becomes infected when the larval or nymph stages feed on infected rodents. The infected nymph or adult may subsequently infect a dog, human, or other mammalian host during feeding (transstadial transmission). Although Lyme disease has great regional importance in parts of the northeastern and midwestern United States, it is also present in other regions of the United States and in Europe. In the western United States, B. burgdorferi is transmitted transstadially by the western black-legged tick, Ixodes pacificus. The disease is of both veterinary and public health significance because both dogs and humans are susceptible to Lyme borreliosis. Another species, Borrelia lonestari, causes a unique form of borreliosis called STARI (southern tick-associated rash illness) in humans in the southeastern United States. B. lonestari is transmitted by the lone star tick, Amblyomma americanum.