DETECTION OF BORRELIA-BURGDORFERI DNA IN MUSEUM SPECIMENS OF PEROMYSCUS-LEUCOPUS

To determine whether Borrelia burgdorferi was enzootic within the Unit ed States at the beginning of the 20th century, ear skin samples taken from museum specimens of the white-footed mouse (Peromyscus leucopus) were examined for evidence of spirochetal DNA. In total, 280 samples from mice collected between 1870 and 1919 were analyzed by a nested po lymerase chain reaction protocol. Of these, 2 specimens from the vicin ity of Dennis, Massachusetts, during 1894 were reproducibly positive f or B. burgdorferi OspA sequences. The remaining 278, representing both currently endemic and nonendemic sites, were negative for spirochetal DNA. These studies suggest that the agent of Lyme disease was present in a suitable reservoir host in the United States before the turn of the century and provide evidence against a hypothesis of recent introd uction of this zoonotic agent to North America.