Zoonotic Diseases: Federal Actions Needed to Improve Surveillance and Better Assess Human Health Risks Posed by Wildlife

Fast Facts

There are more than 200 known zoonotic diseases—those caused by pathogens that spread between animals and humans. Domestically, zoonotic disease risks can come from U.S. wildlife and animals imported from abroad.

While federal agencies are developing a surveillance system to detect zoonotic diseases in U.S. wildlife, they could also do more to improve collaboration—including sharing information on emerging diseases.

Some of the federal regulations on wildlife imports were put in place in reaction to past outbreaks. They may not be sufficient to proactively prevent future outbreaks.

We recommended that agencies address these and other concerns.

A person, a monkey, a bat, a pig, a rodent, and two coronavirus images in front of a globe with alert symbols on various parts of the world.

Highlights

What GAO Found

Zoonotic diseases, which are transmitted between animals and humans, can spread in any setting where people and animals interact—including forests, farms, or live animal markets. Zoonotic pathogens, such as coronaviruses and avian influenza viruses, are more likely to infect people in crowded, unsanitary settings, where multiple animal species from a wide geographic area intermingle. In general, the risks of a human outbreak increase when zoonotic pathogens are novel—because of a lack of immunity in humans—and when they can spread rapidly from person to person.

Zoonotic Diseases Can Be Transmitted by Animals such as White-Tailed Deer, Nonhuman Primates, and Rodents

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Federal agencies conduct some surveillance for zoonotic diseases in U.S. wildlife but have not fully coordinated certain efforts. For example, the Animal and Plant Health Inspection Service (APHIS) and the U.S. Geological Survey (USGS) have taken initial steps to establish a national surveillance system that would better position the U.S. to address emerging wildlife diseases. As they work to establish this system, more fully following GAO's leading collaboration practices would enhance their efforts. These practices include clearly defining common outcomes and involving relevant participants. In addition, USGS is leading the development of a national wildlife disease database. The 2022 National Biodefense Strategy calls for agencies to develop the ability to rapidly detect and share information on emerging animal pathogens that pose a significant biological threat. However, obstacles related to interoperability and privacy currently prevent the incorporation of APHIS data into the national wildlife disease database. By working together to address these obstacles, the agencies could better support early detection of zoonotic disease outbreaks.

The Centers for Disease Control and Prevention (CDC) and other agencies regulate the importation of certain wildlife species, in part to mitigate the risk of introducing zoonotic diseases to the U.S. In some cases, CDC has issued regulations after outbreaks have occurred, such as banning rodents from Africa after they were linked to a 2003 monkeypox outbreak in the U.S. However, some species of imported wildlife known to be capable of carrying zoonotic diseases, such as rodents not from Africa, are allowed to enter the U.S. without CDC restrictions. Further, CDC has not comprehensively identified and characterized risks related to imported wildlife. As a result, CDC's current approach may not be sufficient to prevent outbreaks. If CDC comprehensively assessed disease risks to inform decisions about regulating imported wildlife, it could help prevent the introduction of zoonotic diseases into the U.S.

Why GAO Did This Study

Major outbreaks of zoonotic diseases have caused millions of human deaths and cost billions of dollars. Zoonotic diseases can spread to people from U.S. wildlife or animals imported from other countries.

A congressional report directed GAO to review issues related to the emergence of zoonotic diseases. This report examines (1) settings where zoonotic pathogens can spread and risk factors for outbreaks; (2) federal efforts to conduct and coordinate surveillance for zoonotic diseases in U.S. wildlife; and (3) federal regulation of imported wildlife to prevent introduction of zoonotic diseases into the U.S. GAO reviewed scientific articles and regulations; reviewed agency strategies and agreements; analyzed data; and interviewed federal officials and other experts. GAO also assessed agency collaboration against GAO's leading practices identified in prior work.

Recommendations

GAO is making five recommendations: two each to APHIS and USGS and one to CDC. The recommendations include that APHIS and USGS improve collaboration to establish a national wildlife disease surveillance system and that CDC comprehensively assess zoonotic disease risks for imported wildlife. Regarding the recommendations, APHIS did not comment, USGS concurred, and CDC did not concur. GAO continues to believe that addressing all five recommendations is important.

Recommendations for Executive Action

Agency Affected	Recommendation	Status
Animal and Plant Health Inspection Service	The Administrator of APHIS should more fully follow leading practices for collaboration while coordinating with USGS to develop and implement a national wildlife disease surveillance system. This should include clearly defining common outcomes, involving relevant participants, and identifying resources and staffing. (Recommendation 1)	Open In December 2023, officials from both APHIS and USGS said that they have been working with other relevant agencies in efforts to develop the surveillance system through agreements separate from the one established in February 2021. APHIS estimated that a surveillance system that encompasses USGS and APHIS actions and processes will be defined and implemented by June 30, 2024, dependent on available resources.
U.S. Geological Survey	The Director of USGS should more fully follow leading practices for collaboration while coordinating with APHIS to develop and implement a national wildlife disease surveillance system. This should include clearly defining common outcomes, involving relevant participants, and identifying resources and staffing. (Recommendation 2)	Open In December 2023, officials from both APHIS and USGS said that they have been working with other relevant agencies in efforts to develop the surveillance system through agreements separate from the one established in February 2021. APHIS estimated that a surveillance system that encompasses USGS and APHIS actions and processes will be defined and implemented by June 30, 2024, dependent on available resources.
Animal and Plant Health Inspection Service	The Administrator of APHIS should work with USGS to resolve data-sharing concerns and implement enhancements that would facilitate APHIS's participation in USGS's national wildlife disease database. (Recommendation 3)	Open In June 2023, USDA stated that it agreed with this recommendation and that it expects to complete implementation of a shared data system by June 2024, as long as funding remains available and there are no contractor issues. As of March 2024, we are continuing to track the agency's implementation of this recommendation.
U.S. Geological Survey	The Director of USGS should work with APHIS to resolve data-sharing concerns and implement enhancements that would facilitate APHIS's participation in USGS's national wildlife disease database. (Recommendation 4)	Open As of March 2024, we are following up with the agency on any actions taken to implement this recommendation.
Centers for Disease Control and Prevention	The Director of CDC, in collaboration with other agencies, as appropriate, should comprehensively assess zoonotic disease risks related to imported wildlife to inform CDC's decisions about regulations. Such an assessment could include identifying high priority categories of wildlife and then conducting risk assessments for those particular categories. (Recommendation 5)	Open As of February 2024, CDC agreed that qualitative and quantitative public health risk assessments are valuable for informing policy decisions but that comprehensively assessing zoonotic disease risks was too broad. The agency stated that the recommendation implied conducting public health risk assessments for wildlife that are not known to pose a zoonotic disease risk, which would not be a good use of resources. CDC also said the Smithsonian Institution's project to rank the risk of imported wildlife made GAO's recommendation duplicative. GAO continues to believe that CDC could use a risk-based approach--for example, identifying high priority categories of wildlife for risk assessments--to use its resources efficiently and that it could do so in collaboration with other agencies, such as the Smithsonian Institution, as appropriate.