Primary drug-resistant tuberculosis in children. Emergence of primary drug-resistant strains of M. tuberculosis to rifampin.

A prospective study of primary drug-resistant strains of Mycobacterium tuberculosis among children was begun at the Kings County Hospital Medical Center of Brooklyn in 1961 and reported at 5 4-yr periods through 1980. The present report extends our observations of primary drug-resistant tuberculosis in children through 1984. The salient finding in the present report was the increase in primary drug resistance to rifampin, 3 of 19 strains resistant in the last period of study (1981 to 1984) as compared with 1 of 96 strains isolated in the previous 3 periods of study (1969 to 1980). This increase was significant (p less than 0.02) even though the number of strains isolated was small. There were continued low resistance rates to ethambutol and para-aminosalicylic acid and stable resistance rates for isoniazid and streptomycin.