Muddiest Point 11/5

I have a couple of muddiest points. First, on the objectives page number 8. Describe how the immune system reacts when the disease AIDS or H5N1 is contracted and its effect on the immune system. Include: Infection, Effect on the viruses on cells, Spread of the Disease, and Treatment and prevention for the Disease. When it says describe how it reacts when the disease is contracted, does that just mean how it occurs or how it is diagnosed?

Also, number 9. Explain how the following impact infectious disease: global warming and local habitat disruption, overpopulation and urbanization, and poverty and quality of health care. I don't think I remember learning about these. If someone knows the answer to any or all of these please comment. Thanks!