In the United States, seven of 17 FDA licensed antimicrobials currently used subtherapeutically in food animals to promote growth or enhance feed efficiency are also used in or select for cross-resistance to antimicrobials in human therapy. Virginiamycin, which is only used at subtherapeutic levels, has resulted in a reservoir of Synercid-resistant E. faecium in food animals. There is sufficient scientific evidence that subtherapeutic use of antimicrobials in food animals can select for antimicrobial resistance and do not meet this food safety criteria. In December 1998, US Food and Drug Administration proposed a new framework for evaluation of antimicrobials used in food animals. Although the proposed framework may be used to evaluate the existing approvals for subtherapeutic uses of antimicrobials in food animals, the details of how the proposal would be implemented remain to be determined, making it unlikely that the subtherapeutic use of these antimicrobials would be addressed for several years.
More timely action is necessary to protect the public health.
Antimicrobials which are used in human medicine, or which select for resistance to antimicrobials which are used in human medicine, should not be used to promote the growth of food animals.