-Few subjects displayed a rash. Although all subjects were infected, only one of the 10 displayed a rash with central clearing, the classical bulls-eye rash. The subject that developed this rash, interestingly, never mounted an immune response to five borrelia antigens throughout the study period, prior to and following treatment.
-Organs may be infected even if antibody tests are negative. One subject which tested negative for B. burgdorferi by skin biopsy cultures, PCR and in vivo cultures, was found to have B. burgdorferi infecting the heart. Another untreated subject, who was ultimately shown to have residual Lyme bacteria in the bladder, showed a decrease in immune response over the course of infection, with a negative xenodiagnosis test in the late stage, which would signal that the animal self-cured.
Intact spirochetes were found in three of five treated and four of five untreated subjects based on xenodiagnosis results 12 months after the tick bite.
-Immune responses to B. burgdorferi varied greatly post-treatment, with one subjects antibody levels dropping to pre-bite levels for three antigens while another subject experienced elevated antibodies for the same antigens throughout the study period. This is significant because it demonstrates that subjects infected with the same strain of B. burgdorferi may have different immune responses to the same antigen. And, because humans, like primates, are genetically diverse, it underscores that testing antibody responses may be inherently unreliable as a singular diagnostic modality for Lyme disease.
-Widespread and variable microscopic disease was observed in all infected subjects, despite antibiotic treatment. Compared to uninfected subjects of the same age, infected subjects in this study (treated and untreated) demonstrated Inflammation in and around the heart, in skeletal muscles, joints, and the protective sheath that covers the brain, and near peripheral nerves.
-Rare, but intact B. burgdorferi spirochetes were found in the tissues of both the treated and untreated subjects. In two subjects treated with doxycycline, multiple Lyme bacteria were observed in the brain tissue. Others organs in which the spirochetes were observed included the heart, joints, bladder, skeletal muscle and adjacent to peripheral nerves.