Slowly progressive, degenerative, neurologic disorder. See Morbus Parkinson and Parkinsonian Disorders programs. Also Use Chlamydia Pneumoniae, and see Nocardia Asteroides.Encyclopedia Entry for Parkinson's Disease :Parkinson's disease. Can be caused by Xenotropic Murine Leukemia Virus (XMRV), Influenza A virus, Toxoplasma gondii, Mycoplasma Fermentans, Chlamydia Pneumoniae, and Nocardia Asteroides.Information from Marcello Allegretti.