Interestingly, no spirochetes were isolated from a series of other small and medium-sized mammals from Georgia, including three marsh rice rats (Oryzomys palustris), 63 raccoons (Procyon lotor), 14 house mice (Mus musculus), eight golden mice (Ochrotomys nuttalli), three Norway rats (Rattus norvegicus), one eastern cottontail rabbit (Sylvilagus floridanus), 37 Virginia opossums (Didelphis virginiana), nine eastern gray squirrels (Sciurus carolinensis), two southern flying squirrels (Glaucomys volans), one black rat (Rattus rattus), one oldfield mouse (Peromyscus polionotus), one pine vole (Microtus pinetorum), and one southern short-tailed shrew (Blarina carolinensis).

Small and medium-sized mammals from Florida from which no spirochetes were isolated included 12 golden mice, one rice rat, one black rat, five house mice, eight eastern gray squirrels, one raccoon, and 49 Virginia opossums. Species that were cultured and negative from South Carolina included one golden mouse, 13 rice rats, two white-footed mice (Peromyscus leucopus), one black rat, and one eastern harvest mouse (Reithrodontomys humulis).