Mycobacterial testing in clinical laboratories that participate in the College of American Pathologists' Mycobacteriology E survey: results of a 1993 questionnaire.

Participants in the College of American Pathologists' Mycobacteriology E proficiency testing survey in 1993 were asked to complete a questionnaire addressing mycobacterial test methods, test volume, and frequency of detection of drug-resistant Mycobacterium tuberculosis (MTB). A similar questionnaire had been distributed in 1992. The population responding to the 1993 questionnaire changed, because of a shift of small hospitals to the limited Mycobacteriology E1 survey, and the format of some questions was altered, so a direct comparison of 1992 and 1993 responses was not always possible. Among participants who answered the questions in both years, there was a significant increase in the use of the fluorochrome stain (57% in 1992, 61% in 1993), BACTEC TB for culture (34% in 1992, 38% in 1993) and susceptibility testing (51% in 1992, 61% in 1993), and DNA probes for identification (30% in 1992, 51% in 1993). The percentage of participants who processed respiratory specimens at least seven times per week increased from 9% in 1992 to 13% in 1993, and the percentage processing five times per week increased from 68 to 72%. The percentage of respondents who reported an identification of MTB within 21 days of specimen receipts and susceptibility test results within 28 days in 1992 and 1993 increased from 30 to 41% and from 12 to 19%, respectively. In regard to resistant MTB, 177 institutions in 1991 and 291 in 1992 reported resistance to isoniazid, and 114 in 1991 and 187 in 1992 reported resistance to both isoniazid and rifampin. Laboratorians are to be applauded for using the more rapid mycobacterial testing methods; however, given that tuberculosis remains a problem, this trend must continue.