WIDESPREAD DISSEMINATION OF A DRUG-SUSCEPTIBLE STRAIN OF MYCOBACTERIUM-TUBERCULOSIS

In New York City, a large proportion of new tuberculosis cases has bee n caused by 1 drug-susceptible strain (called C strain) of Mycobacteri um tuberculosis, Between 1991 and 1994, among >600 tuberculosis patien ts consecutively identified in four large hospitals in the city, 54 wi th C strain, 69 with non-C Cluster pattern strains, and 42 with nonclu ster pattern strains were studied, Susceptibility to reactive nitrogen intermediates (RNI) of selected isolates was compared, In a case-cont rol analysis, 51% of patients with C strain, 28% with non-C cluster st rains (P<.05), and 14% with noncluster strains (P<.01) were found to b e injection drug users, C strain but not 13 other unrelated isolates w ere resistant to RNI, Injection drug use may provide a selective press ure for an RNI-resistant tubercle bacillus to emerge, which may give t he organism a biologic advantage and explain the widespread disseminat ion of C strain M. tuberculosis within the city.