Epidemiological data point to the involvement of a cow milk factor in the etiology of multiple sclerosis (MS). Eleven circular DNA molecules closely related to transmissible spongiform encephalopathy (TSE)-associated isolate Sphinx 1.76 were isolated from healthy cattle serum, cow milk, and serum and brain tissue from MS patients.
Whitley, C., Gunst, K., Müller, H., Funk, M., zur Hausen, H., & de Villiers, E. M. (2014). Novel replication-competent circular DNA molecules from healthy cattle serum and milk and multiple sclerosis-affected human brain tissue. Genome Announcements, 2(4). https://doi.org/10.1128/genomeA.00849-14