As you undoubtedly know, epidemics and pandemics are as old as civilization. Ohio had it's share of epidemics in the 19th century. One way to find out what and when the worst of these were is to google "epidemics in Ohio" (in quotes) several sites come up. One at http://ohshelby.ancestralsites.com/epidemics.html
tells us that in 1882-1883 there was a smallpox epidemic in Ohio.