U.S. EPA proposes framework for interagency collaboration on the review of potential for resistance from antibacterial and antifungal pesticides

On July 2, 2024, the U.S. Environmental Protection Agency (EPA) released for public comment a draft framework for expanding federal collaboration on the review of antibacterial and antifungal pesticides. EPA coordinated with the U.S. Department of Health and Human Services (HHS), the U.S. Department of Agriculture (USDA), and the White House Office of Science and Technology Policy in developing this framework. As noted in this framework, EPA intends to establish a process to consider expert input from other federal agencies during its evaluation of antimicrobials that may adversely impact the efficacy of human or animal drugs. This framework outlines a process for EPA to collaborate with other federal agencies in a manner that recognizes the benefits of these pesticides to agriculture while minimizing their impact on public health, and that considers the goals of the One Health model. One Health is a multidisciplinary approach to improve public health outcomes by analyzing linkages between humans, animals, and the global environment.

Background

Many farmers use pesticides to treat bacterial and fungal diseases that affect their crops. If left uncontrolled, these diseases can be extremely damaging and sometimes threaten entire industries. Fungal diseases, such as apple scab, various rusts, and gray mold, and bacterial diseases, such as fire blight or citrus greening, can reduce crop yield or quality. Some diseases, such as citrus greening, can take entire orchards out of production if left uncontrolled.

While antibacterial and antifungal pesticides can manage these diseases on crops, there is early emerging evidence that the use of these pesticides can reduce the effectiveness of some human and animal antibacterial and antifungal drugs. This is because some of these pesticides share characteristics with antibacterial and antifungal drugs. Thus, if a strain of bacteria or fungi becomes resistant to a pesticide, that strain may also become resistant to human or animal drugs that share similar characteristics with the pesticide. As a result, a drug that would normally be used to treat a bacterial or fungal infection may not work well against those resistant bacteria or fungi.

For example, farmers sometimes apply antifungal pesticides to protect their crops from fungal diseases. However, these antifungal pesticides can potentially make strains of a specific fungi (Aspergillus fumigatus) resistant. If a human breathes in this resistant strain of fungi, they sometimes develop a fungal infection known as aspergillosis. Where the infection is caused by a strain of Aspergillus fumigatus that is resistant to antifungal pesticides, the infection could also be resistant to antifungal drugs that share characteristics with those antifungal pesticides. As a result, the antifungal drug that doctors would normally prescribe to treat aspergillosis may no longer be effective. Alternative treatments, if they are even available, may not be as effective or have worse adverse side effects.

On September 26, 2023 EPA, HHS, and USDA issued a concept note to gather initial feedback on the proposed framework. The concept note was intended to be the first step in creating a process to improve assessments of pesticides that may adversely impact the efficacy of human or animal drugs. The concept note identified outstanding research questions about how resistance occurs and how agricultural practices can affect its growth and spread. The agencies received over 5,200 comments from stakeholders in public health, government, research, and industry. The feedback emphasized further regulation in alignment with One Health, the significance of antimicrobials in food and medical systems, and remaining uncertainties in antifungal and antibacterial research. Because very few comments directly responded to the specific charge questions asked by the concept paper, the agencies did not receive sufficient information to resolve the many scientific questions about assessing the potential risk of pesticides to adversely impact the efficacy of human or animal drugs. As discussed in the draft framework, the agencies continue to seek information about how to best resolve these remaining scientific questions and have included in the draft a research agenda with the key questions for which the agencies are seeking answers.

Framework and Next Steps

EPA has developed a draft framework establishing a process to consider expert input from other federal agencies during its evaluation of antimicrobials that may adversely impact the efficacy of human or animal drugs. This framework describes the Agency's plan to establish and chair a working group with subject matter experts from across the federal government, including HHS, USDA, and other agencies as appropriate. The framework would generally apply to pesticides that have the potential to cause resistance with a medically important human or animal drug. When EPA develops risk assessments, it expects to consult with the working group to provide expert opinion on draft assessments for pesticides covered by the framework.

To read the proposed framework and submit a public comment, visit docket EPA-HQ-OPP-2023-0445 at www.regulations.gov. The comment period will be open for 30 days, closing on August 1, 2024. EPA will consider public feedback before publishing the final framework, which the Agency intends to issue by the end of 2024.

Read EPA's Proposed Framework