Antituberculosis drug resistance in south Texas.

The incidence of antituberculosis drug resistance in South Texas has been tabulated. Age, sex, and ethnic group were not found to significantly influence the incidence of resistance. The incidence of resistance to isoniazid (NH) was 16.4%, ethambutol, 3.9%, rifampin, 10.6%, and streptomycin, 7.8%. There was a 7.3% rate of resistance to INH and/or ethambutol or rifampin for any individual organism (i.e., to 2 of the 3 most commonly used antituberculosis drugs). We conclude that the incidence of single and multiple antituberculosis drug resistance in South Texas is higher than previously reported.