Air Purifiers

Hi guys…..I am in college and since this semester my new roomate seems to be getting sick pretty often….everytime she gets sick…I get sick….We don’t really have direct contact…Because I rarley stay in the room when she is there…. I spray everything that i own in my room down….Pretty much anything that she touches….I try not to touch anything with my bare hands if i do…i spray it down with lysol and use hand sanitizer…..I’m getting pretty disgusted by her sickness…n e ways…Can I get sick by my being in the room and breathing in the air….?…
Thanks
I also wash my hand pretty often
I also wash my hands pretty often

I am moving into my frat house in a few days and my roomate says the room is covered in thick dust, i need to buy an air purifier but i dont know which is best, i am looking to spend under 5. Also i need to know if there is any cleaning supplies or things i can use on the carpeting which is very dusty and dirty. Also the mattress in the room is dusty. Thanks for your help.