In the past several years, the world has seen an unprecedented emergence of diseases with epidemic and pandemic potential. Epidemics of West Nile virus, Ebola, Zika, COVID-19, and mpox show how the health of people, animals, and our shared environment are closely connected. For as long as people have lived with and around animals, there has always been the potential for sharing diseases. The majority of infectious diseases that affect people are zoonotic, which means they can spread between animals and people. A One Health approach is critical to most effectively protect health for people, animals, plants, and our shared environment. One Health recognizes that the health of people, domestic and wild animals, plants, and our shared environment are closely linked and interdependent. Shared threats at the human-animal-environment interface can be addressed using a One Health approach that brings together experts from all sectors.

In today's connected world, people and animals interact more closely and more often than they have ever before. We have pets in our homes, work with animals on farms, see wildlife in our yards, visit animals in public settings like zoos, and even bring animals into our classrooms and healthcare facilities. Changes in climate and land use have changed animal habitats and movement, often bringing wildlife into our communities and closer to our homes and daily lives. But with this increased human-animal-environment connection comes the increased risk for new and reemerging zoonotic diseases in both people and animals that can have a profound impact on societies by affecting economies, food safety and security, livelihoods, and global health.

It's not a question of if but when the next zoonotic disease with pandemic potential will come. This reality is why a One Health approach to surveillance is crucial for finding diseases at the human-animal-environment interface early enough to prevent their spread. It's also important for our ability to address conservation, biodiversity, and protect the environment.

1. One Health surveillance is crucial for early detection of diseases.

Historically, each sector — human, animal, and environment — operates its own surveillance system for One Health threats like zoonotic diseases. A One Health approach to surveillance would ensure there is coordinated data collection and sharing across all relevant sectors. Connecting surveillance across sectors means that there is a way to detect new or existing diseases at the human-animal-environment interface earlier, resulting in more accurate and complete information to inform decision-making.

Although each sector may collect its own data, using a One Health approach to surveillance means that there are data sharing across relevant sectors to accomplish the goals of the surveillance program. As surveillance systems are modernized, this means that data sharing can more easily occur automatically through field applications and electronic data reporting systems. From a disease prevention standpoint, connecting data from across sectors gives us a more complete picture to find diseases early, identify pathogen reservoirs, and prevent the case or outbreak from spreading on to more people, animals, or between species.

One Health surveillance can also begin when professionals from public health; animal health, both agriculture and wildlife; and environmental sectors as well as others within a community are notified and jointly investigate a new or existing One Health concern (such as a zoonotic disease). This investigation triggers a response that brings together all relevant One Health partners from human, animal, and environmental health sectors to mitigate the threat.

2. One Health surveillance can't happen without collaboration.

A One Health approach recognizes the close connection between human, animal (both domestic and wild), plant, and environmental health and seeks to improve coordination, communication, and collaboration across sectors to improve health for all. The global community needs surveillance systems that brings together information that is useful across public health, agriculture, wildlife, environment, and other relevant sectors to provide the most informed picture of health.

One Health surveillance is crucial for detecting emerging and reemerging zoonotic diseases, but it can't work unless human, animal, and environmental sectors work together at every level of society, from the community to international levels. Each country is part of the global community, with shared responsibility for protecting the health security of that community and our world. One Health surveillance within and between nations will help to detect and prevent epidemics of known infectious diseases as well as the next new disease. This surveillance is most effective when all relevant One Health sectors collaborate and share information early. By keeping public health and animal health surveillance data separate, we fail to acknowledge the role that human-animal interaction plays in the spread of disease.

One Health surveillance originates in communities, where human and animal health events first occur, and from there, the national levels are notified, who report internationally to the World Organisation for Animal Health and the World Health Organization. Countries can use the information collected by national One Health surveillance systems for early detection, for response, and to provide guidance back to the community on disease prevention. For example, in the absence of a One Health approach, dog-mediated rabies surveillance relies solely on waiting for human deaths and then conducting retrospective investigations. Globally, rabies is primarily transmitted through dog bites and is preventable if exposures are recognized early and treated with postexposure vaccinations. Only a surveillance approach that includes detection of rabid animals and their bite victims, called Integrated Bite Case Management, results in meaningful reduction in human deaths. Integrated Bite Case Management is now recognized as the ideal approach for One Health surveillance of rabies cases.

3. Case investigations form the backbone of One Health surveillance.

One Health surveillance starts with investigations into a health event in a person and/or animal: This could be a zoonotic disease, an illness linked to environmental health hazards like harmful algal blooms, or even antimicrobial-resistant infections. Even at this level, it's important that human health, animal health, and environment officials work together during a One Health investigation.

These investigations help scientists and health officials understand why the infection(s) happened, guide care for sick people and animals, determine whether further spread is likely, and take action to prevent more cases in the current outbreak and for preventing future outbreaks. This knowledge is critical in protecting the health and welfare of both people and animals and addressing conservation and biodiversity and protecting the environment.

During the first 3 years of the COVID-19 pandemic, Centers for Disease Control and Prevention (CDC) has worked with federal, state, and local health officials on more than 400 One Health case investigations that involve SARS-CoV-2 spread between people and animals (such as companion animals, captive animals in zoos and aquariums, farmed mink, and free-ranging wildlife). These investigations have helped us and our partners better understand the virus and how it affects animals as well as the potential for virus mutation and spillover of new variants back into people.

Cross-sectoral communication and coordination is critical in allowing health officials from all relevant sectors to act more quickly in response to evolving threats, such as COVID-19.

4. Capacity is needed at the regional, national, subnational, and local level.

The COVID-19 pandemic has led to a better understanding of why One Health surveillance is needed globally. Healthcare staffing shortages and other challenges in the human health sector can directly affect our ability to effectively conduct public health surveillance. Many countries, including the United States, have accelerated efforts to build systems that connect human and animal health surveillance data. However, there is still much work to be done. For One Health surveillance to be effective, data must flow from the local level up to international organizations that can work to monitor and prevent global spread of disease. A prepared workforce across sectors is also key: Medical professionals, public health workers, agriculture professionals, wildlife experts, environmental health professionals, and others should have access to training in One Health.

To build capacity in the United States, CDC has trained and onboarded government health officials from public health, agriculture and livestock, and wildlife sectors to report and share surveillance data on the zoonotic aspects of SARS-CoV-2 through HHS Protect, CDC's online cloud repository of COVID-19 surveillance data. In the future, this platform may be adapted for surveillance of other emerging and endemic zoonotic diseases.

CDC and its partners provide One Health expertise to partners in countries and regions, including providing training and tools to strengthen surveillance and link the sectors together.

5. Human healthcare providers play an important role in One Health surveillance.

Clinicians are crucial partners in the implementation of One Health surveillance systems. Often, they serve as the gatekeepers for surveillance because they are the first point of care for people and are therefore the ones to first identify and diagnose diseases that may span the human-animal-environment spectrum.

Ensuring that human healthcare providers are aware of and advocate for One Health approaches is a critical step in setting up sustainable One Health surveillance systems. Partnerships between healthcare workers and professionals that they may not normally work with, such as animal health professionals, can have a profound impact on mitigating zoonotic diseases and other threats affecting people, animals, plants, and our shared environment.

Source: https://www.medscape.com/viewarticle/987525?src=par_cdc_stm_mscpedt?&faf=1#vp_3