1. Enter the host (get in). 2. Have the ability to remain in a location while the infection gets established. We can call this process establishment (staying in), and this can include increasing the number of pathogenic organisms. 3. Avoid, evade, or compromise the host defenses (defeat the host defenses). 4. Damage the host. 5. Exit from the host and survive long enough to be transmitted to another host (transmissibility, covered in Chapter 6).