Question

in accident Egypt they realized that some illnesses were the result of a specific occurrence or action

Answer 1

Egyptians were smarter about things when is came to illnesses. I believe that is would be action as in them doing something to be sick or getting hurt. Other wise if you are talking about the "occurrence" of a season or something like that. they believed that illnesses can be caused by a variety of different things. like eating certain foods or drinking contaminated water. They also to believe that gods have something to do with illnesses. All in all I think the answer you looking for is action.