Use of a mixture of surrogates for infectious bioagents in a standard approach to assessing disinfection of environmental surfaces.

We used a mixture of surrogates (Acinetobacter baumannii, Mycobacterium terrae, hepatitis A virus, and spores of Geobacillus stearothermophilus) for bioagents in a standardized approach to test environmental surface disinfectants. Each carrier containing 10 microl of mixture received 50 microl of a test chemical or saline at 22 +/- 2 degrees C. Disinfectant efficacy criteria were > or = 6 log(10) reduction for the bacteria and the spores and > or = 3 log(10) reduction for the virus. Peracetic acid (1,000 ppm) was effective in 5 min against the two bacteria and the spores but not against the virus. Chlorine dioxide (CD; 500 and 1,000 ppm) and domestic bleach (DB; 2,500, 3,500, and 5,000 ppm) were effective in 5 min, except for sporicidal activity, which needed 20 min of contact with either 1,000 ppm of CD or the two higher concentrations of DB.