I delegated reading that article to my alternate ego, parasite man. He liked the article enough that he printed it out and saved it to the hard drive.
Parasite man says that the article you provided and other ms histories have always put him in a quandry. Parasite Man suspects that ms and the other autoimmune diseases might have existed to some small degree through entire human history in royalty and the rich because those people have always eaten the best quality food, wore shoes and probably made a point not to walk through other people's poopie.
Conspicuously any documented and suspected ms cases in history always involve royalty or the wealthy. Parasite Man doesn't dare raise the issue that the royal and rich likely got ms because, unlike the general public, their more sterile living conditions didn't allow the parasites to survive.
Therein lies Parasite Man's quandry, it's just as believable to consider the poor didn't have access to medical care and besides, who would go to the effort to document ms in a poor person?
What is well documented is the alarming rise in ms incidence beginning in the mid 19th century which led to our current incidence levels, despite the fact that incidence rates remain rare as ever in the third world countries.