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One Health approach essential to controlling public health threats

Rocky Mountain spotted fever can be deadly to both humans and dogs, but diagnosing a dog with the tickborne illness does not guarantee that the owner will be examined for it, even though he or she may have been exposed to the infection through the same environmental risk factors.

Photo by Shatar Munkhduuren

Richard A. Kock, MA, VMB, VMD, MRCVS, professor of wildlife health and emerging diseases at the Royal Veterinary College, stands over a dead saiga in Mongolia, where he said a virus that spread from livestock as a result of human encroachment killed thousands of the endangered antelopes.

“There have been cases where dogs have been sick and the veterinarians knew about it, but because physicians never heard about it, human cases were missed, leading to some fatalities,” Peter Rabinowitz, MD, MPH, associate professor of environmental and occupational health sciences and director of the Center for One Health Research at the University of Washington, told Infectious Disease News. “If there was a mechanism for the vets to talk to the physicians, they could have alerted them to be more aware of Rocky Mountain spotted fever in their patients.”

In this way, Rocky Mountain spotted fever is a classic example of an infectious disease threat that requires a One Health approach. Rabinowitz has used it as an example when talking with clinicians about the need for a collaborative effort between different disciplines.

“When veterinarians see potentially infectious diseases, there’s no way for them to communicate that with local medical providers,” Rabinowitz said. “What they do now is tell the patient to talk to their doctor, and that may not be the most efficient way of communicating an emerging threat. It puts the onus on the patient to go and say, ‘Well, my vet told me to talk to you and I’m not quite sure why.’ It’s like [a game of] telephone, basically.”

According to the CDC, about 75% of newly emerging diseases and 60% of all known human infectious diseases originate in animals, which can serve as sentinels to warn us of illnesses like Middle East respiratory syndrome (MERS), severe acute respiratory syndrome (SARS) and various avian influenzas, steering responses to outbreaks around the world. Addressing human, animal and environmental health systems, and recognizing how they are related, also can help guide antimicrobial stewardship.

All of this falls under the One Health approach, and experts say clinicians can play an important role by becoming more engaged.

“People have said, ‘Well, One Health is great, but it’s sort of a public or global health thing and it’s not going to affect me and my practice.’ We’re saying, ‘No, there’s a role for clinicians in One Health that we’re trying to define and encourage,’ ” Rabinowitz said. “We feel that clinicians need to be aware of it and implement it in their daily practice.”

Infectious Disease News spoke with several experts to better understand the history of One Health, how it can address infectious disease threats and what clinicians can do to be more involved.

New name, old roots

The core concept of the CDC’s One Health approach is that multiple disciplines collaborate at the local, national and international level to improve the health of humans, animals and the environment. This means that physicians, veterinarians, nurses, pharmacists, dentists, epidemiologists and federal health officials all work together on key health issues.

The concept is much older than the name. In the 1800s, German polymath Rudolf Virchow explored links between human and animal health — two areas of medicine that were traditionally kept separate — and coined the term “zoonoses” for the diseases that pass between them, according to the CDC.

Virchow’s dictum about this relationship is widely cited in literature about One Health: “Between animal and human medicine there are no dividing lines — nor should there be. The object is different but the experience obtained constitutes the basis of all medicine.”

Although the idea of One Health dates back to the 19th century, it has gained in importance in recent years, according to Casey Barton Behravesh, DVM, DrPH, DACVPM, director of the One Health Office in the CDC’s National Center for Emerging and Zoonotic Infectious Diseases.

“Because of a number of factors and issues related to the changing interactions between people, animals and the environment, new diseases have emerged and other diseases have re-emerged, making One Health very relevant today,” Barton Behravesh said in an interview.

The One Health paradigm covers a broad range of topics. According to Infectious Disease News Editorial Board member Arnon Shimshony, DVM, associate professor at the Koret School of Veterinary Medicine, Hebrew University of Jerusalem, the most important goal is diagnosing and controlling zoonotic infections. Shimshony is also an animal diseases and zoonoses moderator for ProMED, an internet-based outbreak reporting system that has its own One Health initiative.

Examples of zoonotic disease outbreaks can be found around the world, caused by human contact with birds, insects and any number of other animals, but especially livestock.