First, it depends on what you mean by your roommate being positive for tb.
Does that mean they have been actually diagnosed, or that their PPD
skin test is positive? A positive skin test does not necessarily mean one has tb. However, TB is very contagious, so if you even suspect your roommate has tb, you need to isolate yourself and your children
from said roommate and get everyone tested.
Answer assisted by David Escobar, Medical Student