<prompt> The area is declared free of epidemicNo new case reported for twice the incubation period of disease since the last caseNo new case reported for the incubation period of disease since the last caseTill last secondary case recoversNo new case reported for six months since the last case  <response>: Investigation of an Epidemic: To define magnitude or involvement time, place, person To determine responsible conditions and factors To identify causes, sources and modes of transmission To make recommendations to prevent reoccurrence. 