A Continuing Study of Primary Drug-resistant Tuberculosis Among Children Observed at the Kings County Hospital Medical Center Between the Years 1961 and 1980

A 20-yr prospective study of the incidence of primary drug-resistant tuberculosis among children treated at the Kings County Medical Center was undertaken in January 1961 and extended through December 1980. There were 355 strains of Mycobacterium tuberculosis isolated during this time, 56 of which were found to be primarily resistant to one or more antituberculosis drugs, giving an overall resistance rate of 15.8%. The study was divided into five 4-yr periods. The resistance rate to isoniazid was 9.9%, varying from a peak of 15.2% in the third period of study (1969 to 1972) to 4.5% in the last period of study. The changes in the rate were not significant. The overall resistance rate for streptomycin was 9.2%. There were significant increases in the resistance rate in the second (1965 to 1968) and third (1969 to 1972) periods of study, but not in the last 2 periods. The rates for PAS (3.4%), rifampin (1%), and ethambutol (0.7%) were low. The type and severity of disease among those infected with a resistant strain were no different from those infected with a susceptible strain. Life-threatening disease was found in 10 of the 56 patients infected with a drug-resistant strain. There was one fatality in a child with meningitis who was treated early in the study. Our experience suggests that rifampin and ethambutol be included in the initial treatment regimen of all children with a life-threatening form of tuberculosis until the susceptibility pattern of the infecting strain is determined, after which the drug regimen can be modified if necessary.