TRANSMISSION OF MULTIDRUG-RESISTANT TUBERCULOSIS IN A LARGE URBAN SETTING

Multidrug resistance has become an increasingly important problem in t he control and prevention of tuberculosis in large urban centers. Alth ough several small outbreaks of multidrug-resistant (MDR) tuberculosis in New York City have been reported, the increase in the number of ca ses is not fully explained by these recognized outbreaks, and the mode s of transmission have not been clearly delineated. Transmission patte rns of MDR tuberculosis in New York City, therefore, were studied by s tratifying Mycobacterium tuberculosis isolates from 167 newly diagnose d tuberculosis patients according to their DNA restriction fragment le ngth polymorphisms (RFLP). Forty-three (34%) of 127 drug-susceptible i solates and 19 (79%) of 24 multidrug-resistant isolates had RFLP patte rns representing possible recent exogenous infection (primary tubercul osis). Patients who had such isolates were more likely to be seroposit ive for human immunodeficiency virus (58%; p < 0.05), non-Hispanic bla ck (56%; p < 0.005), U.S.-born (57%; p < 0.001), and have MDR tubercul osis (79%; p < 0.0005). In a logistic regression model, primary tuberc ulosis remained significantly associated with MDR tuberculosis and bla ck race. In contrast to previous reports, in New York City recent exog enous transmission accounts for most new cases of multidrug-resistant turberculosis.