My roommate has been sick since Sunday night - she was tested for strep on Monday (tested negative), but they told her to come back to the doctor Wed. (today) to be tested again. She tested positive.

I know strep is very contagious and I know it sometimes causes vomiting. Of course as an emet, I wash my hands all the time but theres only so much you can do when an infected person lives with you. She could have stood next to me and coughed and I could have gotten it. The incubation period is like 2 - 5 days.

My question is, how many people v* with strep? Is it normal for adults? (I'm a 20 year old female). How can I avoid it?

Help!