Impact of Drug Susceptibility Testing on Drug Choice in a Tuberculosis Cohort With High Rates of Drug Resistance From the Private Sector in Mumbai

Abstract

Background. Tuberculosis (TB) is the primary infectious disease killer worldwide with 26% of annual cases in India. Mumbai has disproportionately high TB and drug resistance rates, outpacing those elsewhere in India. Most cases are seen in the private sector, creating the opportunity to individualize treatment with drug susceptibility testing (DST). Methods. We present clinical characteristics of a prospective observational cohort of adult patients with TB resistant to isoniazid and rifampin (MDR) from a private hospital in Mumbai. Results. A total of 145 patients were enrolled from October 2015 to April 2016, 84 of whom completed DST. Resistance to a quinolone or 2nd-line injectable drug was found in 50.6% of patients (Pre-XDR TB), and 28.2% were resistant to both quinolones and injectables (XDR). This is a young cohort with median age of 28.9 years. The majority are women (63.5%) and a striking number are students (37.6%). Over 80% were diagnosed in private practice and 62% left work or school due to TB. Median time from symptom onset to TB diagnosis was 1.6 months. MDR TB was diagnosed after a median of 5.5 months. Drugs prescribed varied significantly according to whether DST was performed (table). Follow-up visits have documented high rates of treatment-associated hypothyroidism (32.8%), skin discoloration (25.0%), GI upset (25.0%), joint pain (25.0%), hearing loss (21.9%), neuropathy (18.8%), and kidney injury (15.6%). Conclusion. This unique cohort of resistant TB patients in India offers insight into the importance of drug resistance testing to help guide therapy. The significant side effects associated with MDR TB treatment warrant specific attention to rational drug choices that minimize the impact of these drugs on quality of life and promote treatment completion. (Table Presented) .