Hi,
It's not my area, I'll confess, but I think when you're considering starting any new research project you need to read widely around the subject. Try SCOPUS, Web of Knowledge, even good old Google Scholar and type "HIV/AIDS" "HIV/AIDS Jamaica" then read! Look for gaps in the current literature and areas that interest you. What do you want to know about the impact of HIV/AIDS? How can you find this out? What methods would you use etc... Then you're almost half way there! I'm sorry if I'm teaching you to suck eggs but I remember being lost in the early days of my PhD!
Hope that's a bit helpful :$