Yeah the psychological is interesting.. and autoimmune, right. I wasn't really thinking a disease like diabetes which is caused by lifestyle. I was thinking germs. The bacterias make sense, but I don't know if they have been pandemic scale. But I guess basically over the last century the population increase makes "pandemics" possible whereas before not so much maybe... But in that time I don't think there has been a national-level bacterial contagen. Maybe because that easier to fight with antibiotics and containment.