Significance and Use
This in vivo procedure is designed to test the ability of hygienic handwash and handrub agents to reduce levels of selected infectious viruses from experimentally contaminated fingerpads of adults. Since the two thumbpads and all eight fingerpads can be used in any given test, it allows for the incorporation of input virus control (two), virus remaining viable after the inoculum has been allowed to dry (two), virus eliminated after treatment with a control or reference solution (two), and up to four replicates to assess the virus-eliminating efficiency of the substance under test. No more than 100 μL of the virus suspension are required to complete one test. The results of testing with this test method may form the basis for further tests using a suitable whole-hand test protocol (for example, Test Method E2011).
This test method is designed to be performed by a trained individual, who is responsible for choosing the appropriate host system for the test virus and applying the techniques necessary for propagation and maintenance of host and test virus. For a reference text, refer to Lennette et al (8).
Whereas the method described here relates to testing with viruses of human origin, it can be readily adapted to work with animal pathogenic viruses as well as bacteriophages. Standard methods for working with bacteria (Test Method E2276) and fungi (Test Method E2613) are also available.
Infectious microorganisms left on hands after washing can be reduced further by drying the washed hands with paper, cloth, or warm air (9). A step for the drying of fingerpads after exposure to the control or test substance, therefore, has not been included to avoid virus removal by the drying process itself.
This test method is not meant for use with surgical hand scrubs or preoperative skin preps.
The level of viable virus on each fingerpad after the drying of the inoculum should not be less than 104 infectious units which would permit the detection of up to a 4 log10 reduction in the infectivity titer of the virus by the test substance under the conditions of this test method.
1.1 Human skin is not known to carry viruses as a part of its resident microbiota. Hands transiently contaminated with viruses can, however, act as vehicles for the spread of many types of viral infections. Hand hygiene is meant to reduce the load of viruses and other transient microorganisms on hands, thereby reducing the risk of disease transmission. Such reductions in the virus load may be due to a combination of virus inactivation and mechanical removal of infectious virus from the skin.
1.2 This test method is designed to determine the comparative virus-eliminating effectiveness of microbicidal or non-microbicidal formulations. This test method is not meant for use with surgical hand scrubs or preoperative skin preps.
Note 1—The test method should be performed by persons with training in virology in facilities designed and equipped for work with infectious agents at biosafety level 2 (6).
1.3 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.
1.4 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.