I also have an ancestor who died along with three of his children. Mine was in 1806 in Connecticut. It is my understanding that this disease is caused when infected rat fleas contaminate fresh skin wounds or the flea bite site. Even though it isn't spread from person to person, I suppose it could be considered an epidomic it the problem were widespread. Perhaps something like the Junta Virus that caused so many deaths among Native Americans a few years ago.