As I scour forums on the internet, I find a number of people with MS have a connection to dairy farms. I have an uncle who died of MS and he was a milk man. Numbers of others say they either worked on a dairy farm, lived near one, etc. I struggle to find my own link. My next door neighbor growing up also has MS now, so I wonder if our subdivision was built on old farm lands. Maybe there is a connection with milk and schools. I remember an older study that found teachers were at a high risk along with construction workers. Teachers would likely drink fresh milk served in the cafeteria (our school got it delivered from the farm), while construction workers would be in contact with soil on new work sites. This could also explain clusters among certain schools in Ohio or clusters in small farming towns. I read about one cluster among people who worked together on a single farm.
I also wondered if it could be transmitted by raw apple cider that we would drink every fall since they pick up rotting apples on the ground to make cider, and this bug apparently likes wet, decaying, soil based environments. I saw a publication a few months back where insurance companies found unusually large numbers of MS disability claims came from agricultural workers, and then dairy farms as a subset of that. Even Dr. Swank noted that MS was more common in farm lands. (that could also explain the mystery of low MS in Japan--very few grazing lands).