<prompt> First step in investigation of an epidemic is:-Source identificationVerification of the diagnosisConfirmation of existence of epidemicFormation of hypothesis  <response>: Investigation of an epidemic-chronological steps: 1 Verification of diagnosis - 1st step2 Confirmation of existence of epidemic 3 Defining population at risk 4 Rapid search of all cases and their characteristics 5 Data analysis 6 Formation of hypothesis 7 Testing of hypothesis 8 Evaluation of ecological factor 9 Fuher investigation of population at risk 10 Writing the repo 