Changing practices in mycobacteriology: a follow-up survey of state and territorial public health laboratories

Abstract

The resurgence of tuberculosis, which includes an increase in the isolation of multidrug-resistant strains of Mycobacterium tuberculosis, emphasizes the need for more rapid laboratory testing for identification of the etiological agent of the disease. In December 1991, state and territorial public health laboratories were surveyed to determine the methods that they were using for testing and reporting of M. tuberculosis. A follow-up survey was conducted in June 1994 to measure changes in the testing and reporting practices that had occurred as a result of efforts focused on the disease and on laboratory improvement. Completed questionnaires were received from 51 of 55 laboratories. Comparative data indicate that the proportion of laboratories reporting testing results within the number of days recommended by the Centers for Disease Control and Prevention has increased. Starting from the time at which the laboratory receives the specimen, the proportion of laboratories reporting the results of microscopic smear examination within the recommended 24 h has increased from 52.1 to 77.6%; the proportion reporting isolation and identification within 21 days has increased from 22.1 to 72.9%; and the proportion reporting results of isolation, identification, and drug susceptibility testing within 28 days has increased from 16.7 to 48.9%. Use of the recommended rapid testing methods has also increased: the proportion of laboratories using fluorescence staining for acid-fast microscopy has increased from 71.4 to 85.7%, the proportion using BACTEC for primary culture has increased from 27.1 to 79.6%, the proportion using rapid methods for M. tuberculosis identification has increased from 74.5 to 100.0%, and the proportion using BACTEC for primary drug susceptibility testing has increased from 26.2 to 73.3%. By implementing the recommended methods for M. tuberculosis testing and reporting, state and territorial public health laboratories are now able to transmit results to physicians more rapidly.