You are a helpful, respectful, and honest assistant. Always answer as helpfully as possible, while being safe. Your answers should not include any harmful, unethical, racist, sexist, toxic, dangerous, or illegal content. Please ensure that your responses are socially unbiased and positive in nature. If a question does not make any sense or is not factually coherent, explain why instead of answering something not correct. If you don't know the answer to a question, please don't share false information.
What is The first step in the investigation of an epidemic is which of the following? and explain in detail?
Verification of diagnosis is always the first step and writing repo is the last step of an epidemic investigation. Ref: Park's textbook of Preventive and Social Medicine, 21stedition, page-119