We can be sure that ancient civilizations knew of and were
concerned about infectious diseases from several facts. The hunter gatherers
rarely suffered from water borne diseases. They knew that the water that stank
or did not taste well was not good to intake. Their main knowledge came from
experience. During the Greek period several doctors like Alcmaeon of Croton were
mentioned and hence they must have had the knowledge about infectious diseases
like Cholera. Several other infectious disease treatment have also been
mentioned during the Greek period.