A mycobacteriology proficiency testing program using simulated sputum specimens.

The New York State Department of Health proficiency testing program in mycobacteriology determines the ability of a laboratory to isolate the acid-fast bacillus present in a simulated specimen and to identify the strain. Until 1964 the specimens were autoclaved normal sputa seeded with mycobacteria. When mandatory testing was introduced by law in 1964, more specimens were needed. These have been prepared in simulated sputum bases, first skimmed milk, then granulated hog gastric mucin. The bases are seeded with Mycobacterium tuberculosis and other mycobacteria; Pseudomonas aeruginosa is added to simulate the contamination in clinical specimens. Laboratory performance in general has improved as a result of the proficiency testing and the concomitant educational program, but laboratories processing more than 200 specimens a year continue to perform best.