Laboratory Safety in Research with Infectious Aerosols

Abstract

THE MEANS by which man becomes in¬ fected in the laboratory depend to a con¬ siderable extent upon his experimental proce¬ dures.But in the absence of procedures that especially predispose to aspiration, penetrating self-inoculation, or dermal contamination, the most common method of infection is the inhala- tion of accidentally formed microbial aerosol. How Accidental Infection OccursA 1950 survey of 1,342 laboratory-acquired infeetions in the United States revealed that recognizable accidents accounted for only 16 percent (1).The precipitating act, source, or means of infection was unknown in 80 to 84 per¬ cent of the cases.At Fort Detrick, exhaustive on-the-spot investigation of 90 laboratory ill¬ nesses occurring from 1953 to 1957 could reduce this unknown group to no less than 65 per¬ cent (2).Common manipulations with the inoculating needle, pipette, syringe, centrifuge, lyophilizer, and blendor create bacteria-laden aerosolized particles suitable for inhalation.Table 1 pro¬ vides illustrative data from a larger series of determinations concerning the number of such particles that may be recovered within 2 feet of the work area by air sampling (3, h).These numbers will be increased somewhat if arthrospores of Coccidioides immitis are used (5).