A paper in the Journal of Advanced Nursing looks at this. Everyone diagnosed at one London hospital with TB was interviewed with regard to factors such as housing, past imprisonment, drug use. 32 percent of those interviewed were homeless (as defined by the authors), 39 percent were in receipt of welfare, 13 percent had no income, and over a third of people had no one to remind them to take their medications.
The paper is:
Craig GM, Booth H, Story A, Hayward A, Hall J, Goodburn A, Zumla A. The impact of social factors on tuberculosis management. Journal of Advanced Nursing 2007; 58 (5): 418–424.