He was interested in a disease called bacillary dysentery, which is a bacterial infection that causes severe diarrhea, and back then, was actually killing a lot of people, because after all, no cure for bacterial infections had been invented.
Han var interesseret i en sygdom,  som kaldes bacille dysenteri, som er en bakteriel infektion,  der forårsager alvorlig diarré, og som dengang, dræbte mange mennesker, fordi man ikke havde en behandling for bakterielle infektioner.