J Clin Microbiol. 1984 Dec;20(6):1099-101.
Johnson RC, Marek N, Kodner C.
QUOTE- "Although these spirochetes did not cause any outward signs of illness in these animals, they did cause a generalized infection. Spirochetemia was present during the first 6 days of infection. At 14 days postinfection, spirochetes could be isolated from one or more of the following organs: spleen, eyes, kidneys, liver, testes, and brain. Spirochetes were isolated from the eyes and kidneys of one animal 52 days postinfection, suggesting that these organisms may cause a persistent infection."
Link Here- https://www.ncbi.nlm.nih.gov/pubmed/6520220