Primary Drug-Resistant Mycobacterium tuberculosis Isolated in Massachusetts in 1972

Among the 731 persons with Mycobacterium tuberculosis infection who were tested in Massachusetts in 1972, an incidence of 3.16 % (23 cases) of primary resistance to antituberculous drugs was observed. Nine cases (1.23 %) were re-sistant to isoniazid alone, and six cases (0.82 %) were resistant to three drugs (isoniazid, streptomycin, and either para-aminosalicylic acid or ethambutol). Four cases (0.55%) were resistant to streptomycin and para-aminosalicylic acid combined, and one case (0.14%) was resistant to each of the following: strepto-mycin alone, isoniazid and streptomycin, isoniazid and para-aminosalicylic acid, and isoniazid and ethambutol. Twelve of the 23 primary drug-resistant patients had a history of alcoholism or addiction to narcotics; 10 of the 12 addicts were infected by multiple drug-resistant tubercle bacilli. In this study, primary resistance to one or more antituberculous drugs was defined as the presence of tubercle bacilli in a patient who had not re-ceived any antituberculous chemotherapy befor