Bird viruses in multiple sclerosis: combination of viruses or Marek's alone?

This is a short report confirming recent articles that birds are very likely involved as vectors of the exogenous causative agent of multiple sclerosis (MS). It also critically reviews the most recent article (MacGregor, H. and Latiwonk, Q., Neurol. Res., 15 (1993) 391-394.) in which a high percentage of serums from MS patients reacted positively with Marek's antigen and it was accidentally discovered that Epstein-Barr virus antibodies also cross-react positively with Marek's antigen. This discovery might help explain the complex epidemiology of MS (an infectious mononucleosis infection would immunize a person against future mononucleosis and a Marek's infection). A table comparing the similarities between MS and Marek's is included. Other possible avian viral candidates are entertained plus the possibility of various viral combinations within a protective chlamydial plasmid including Marek's and avian retroviruses.