Experimental animal studies have shown that Borrelia burgdorferi, the agent of Lyme borreliosis, consistently establishes persistent infections in a variety of immunocompetent hosts, including laboratory mice [1], white-footed mice (Peromyscus leucopus) [2], [3], [4], rats [5], hamsters [6], guinea pigs [7], gerbils [8], dogs [9], and nonhuman primates, including rhesus macaques (Macaca mulatta) [10] and baboons (Papio spp.