Tuberculosis patients in an Indian mega-city: Where do they live and where are they diagnosed?

TB case detection in Chennai is centralized, with four high-volume DMCs making most diagnoses. One-sixth of patients are from outside the city, most of whom get evaluated at these high-volume DMCs. This calls for better coordination between high-volume city DMCs and rural TB units where many patients may take TB treatment. Patient mobility only partly explains Chennai's urban registration gap, suggesting that pretreatment loss to follow-up of patients who live within the city may also be a major problem.