List the five steps in the infectious disease process and give a brief explanation of each:

1. Incubation Period: The time between the entry of the pathogen into the body and the appearance of the first symptoms. The pathogen is multiplying but has not yet caused significant symptoms.

2. Prodromal Stage: The initial appearance of vague symptoms, such as fatigue or mild fever. The pathogen is continuing to multiply and the immune response begins.

3. Illness Stage: The period during which the disease is most severe and the characteristic symptoms of the infection are evident. The immune system is actively fighting the infection.

4. Decline Stage: The symptoms begin to subside as the immune system overcomes the pathogen or the effects of treatment take hold. The patient's condition starts to improve.

5. Convalescence Stage: The recovery phase where the body heals and returns to normal. The patient regains strength, and the immune system eliminates the remaining pathogens.