Fast forward a decade or two. You walk into a hospital waiting room and quickly glance around.
Lions and tigers and bears! Oh my!
Well, maybe it won’t be that dramatic, but does the future of medicine involve bringing together physicians and veterinarians? It just may.
An Old Solution to New Problems
“One Health” is the idea of researchers and practitioners from veterinary and human medicine working together to solve health problems. The term “One Health” is relatively new, but the concept goes back several thousand years.
Aristotle was among the first to note similarities in anatomy and physiology between humans and non-human animals. In 1717, Italian physician Giovanni Maria Lancisi published his landmark work showing that mosquitos were the source of malaria infections in people. A century later German physician Rudolf Virchow wrote, “[b]etween animal and human medicines there are no dividing lines.” The writings of these and other scientists show that the link between human and animal health has long been known.
The Canadian Connection
It took a Canadian to move the ideas of Virchow and others into action. The “Father of Modern Medicine” Sir William Osler taught veterinary students at the Montreal Veterinary College and later become president of the Veterinary Medical Association. Osler is acknowledged as a strong proponent of comparative medicine. Perhaps for this reason he is often incorrectly given credit for the term “One Health”. In reality it wasn’t until 1984 that American veterinarian Calvin Schwabe first coined the term “One Medicine”. Over time “One Medicine” evolved into “One Health” to reflect its inclusion of environmental health, as opposed to simply medical treatment.
One Health and Zoonotic Diseases
Some of the biggest success stories in One Health are in tackling infectious diseases. Severe Acute Respiratory Syndrome (SARS), Creutzfeld-Jacob disease (“Mad Cow”) and avian influenza (“Bird Flu”) are well known examples of human diseases that originated in animals. Infectious diseases that pass from animals to humans are known as ‘zoonotic’ diseases.
Fortunately, large scale outbreaks of zoonotic diseases are rare. However, infectious diseases that pass between species are not as uncommon as you might think. Over 60% of infectious diseases in humans originated in animals. Almost 100 new zoonotic diseases were identified in the first ten years of this millennium alone.
The impact of zoonotic diseases is staggering. They cost the global economy over $100 trillion annually. A single influenza outbreak would erase 5% of global GDP. In terms of human cost, a 2012 study found that 13 of the most common zoonotic diseases caused 2.4 billion cases of illness and 2.2 million deaths worldwide (Grace et al., 2012). These zoonotic diseases disproportionately affected the world’s poorest countries.
Solving SARS
One example of a One Health success story was the SARS outbreak of 2003. In February 2003, an outbreak of ‘atypical pneumonia’ occurred in the Guangdong province of China. Patients did not respond to the normal treatment of antibiotics. Because of the close proximity to Hong Kong – an international travel centre – cases appeared in 26 countries within weeks.
Early cases of SARS in Guangdong province appeared in people who had close contact with animals. Coordinated efforts between veterinarians, researchers and physicians quickly identified both the cause of SARS and determined how it was transmitted. These two points were crucial in treating patients and stopping the spread of the virus.
Interestingly, in a recount of the 2003 SARS outbreak, Peiris and Guan (2004) note that key research into solving the crisis used routine scientific techniques. There was nothing fancy or ground-breaking about the research tools. What was critical was a One Health approach that brought together the expertise of physicians, researchers and veterinarians.
The Untapped Potential of One Health
At its core One Health is the exchange of knowledge between veterinary and human medicine. One area of One Health that is under-appreciated is the translation of biotechnology or therapies from veterinary to human medicine and vice versa.
One example of a therapy that moved between human and veterinary medicine involves a class of drugs termed calcium sensitizers. Calcium sensitizers were developed for human heart failure patients. In the late 1980s and early 1990s, clinical trials showed some beneficial effects in the treatment of human heart failure. But by the mid-1990s the use of calcium sensitizers was questioned in the face of negative clinical trials and minimal benefits with long-term use (Fitton and Brogden, 1994; Asanoi and Inoue, 1996). As a result, calcium sensitizers were largely abandoned as a viable treatment for human heart failure patients.
Heart failure is not an exclusively human disease. Up to half of all Doberman Pinchers have a genetic form of heart failure called dilated cardiomyopathy. Even with aggressive treatment, life expectancy for Doberman Pinschers with dilated cardiomopathy was measured in days or weeks (O’Grady et al., 2008).
In a four year study, Fuentes and colleagues (2002) found that the calcium sensitizer ‘pimobendan’ increased life expectancy of dogs with dilated cardiomyopathy. In 2008, a team from the Ontario Veterinary College at the University of Guelph showed that pimobendan extended the life expectancy of Doberman Pinschers with heart failure from an average of 2 weeks to over 4 months (O’Grady et al., 2008). Later the PROTECT study found that pimobendan delays the development of dilated cardiomyopathy in Doberman Pinschers (Summerfield et al., 2012). Most recently the EPIC study showed that pimobendan has beneficial effects in dogs with a form of heart failure caused by mitral valve dysfunction (Boswood et al., 2018).
A Doberman Pinscher named Rumour who is a patient in research studies at the Ontario Veterinary College designed to improve diagnosis and treatment for heart failure. Photo by Dr. Leanne Stalker.
Interestingly, new human-focused studies have been done following the successful use of calcium sensitizers in veterinary medicine. Although the research is still in its early phases, there are some positive results with calcium sensitizers in human heart failure patients (Altenberger et al., 2018). Knowledge from veterinary cardiologists is being used to change the way calcium sensitizers were originally used in people. In the end we may see a treatment move from human patients to pets and then back to humans.
One Health – Not Just a One Trick Pony
Similarities between human and veterinary cancers also have significant translational potential. Oncolytic viruses – viruses that infect and destroy tumour cells – have long been seen as potentially powerful cancer treatments. However, the immune system of patients destroys the virus before it fully kills the target tumour. This natural immune response hampers the use of oncolytic viruses.
Research by Dr. Byram Bridle from the University of Guelph is helping to solve a problem that limits the use of oncolytic viruses to treat cancer. Dr. Bridle’s group has administered a vaccine before oncolytic viral treatment to protect the virus from destruction. This approach was first tested in mice and the results were promising (Bridle et al., 2010).
Cancer naturally occurs in a number of pets, but similarities between cancer in cats and humans offers the potential for translational treatments between these two types of animals. In 2017, Dr. Bridle’s group collaborated with veterinarians at the Ontario Veterinary College to test their oncolytic virus therapy in cats (Hummel et al., 2017). Cats tolerated the treatment well and the treatment was determined to be safe.
At the same time that studies have been conducted in cats, researchers at the University of Guelph, McMaster University and Beth Israel Deaconess Medical Center have tested oncolytic virus treatment in a preclinical mouse model of ovarian cancer (Matuszewska et al., 2018). A novel combination therapy slowed tumour growth and metastasis and was touted as having the potential to rapidly translate into human clinical trials.
The simultaneous investigation of cancer therapy in human and veterinary medicine creates a more intense and thorough research program. Progress may occur more quickly as a result of preclinical testing in veterinary medicine, while at the same time providing potential benefits to pets with similar diseases.
One Health Obstacles
If One Health is such a great opportunity, then why aren’t governments, universities and other research agencies doggedly pursuing it (pun intended)? In a word: cost.
Some estimates for a global One Health program reach $5 billion annually. The large financial outlay is due in part to the scope and complexity of the problems that fall under the One Health umbrella. A research and medical system that covers human and veterinary medicine requires substantial financial investment to create the human and technical infrastructure.
While it is clear that creating and running One Health programs would be costly, economics actually favor these expenses. First, the cost of a One Health program are a fraction of the nearly $50 billion in annual losses due to epidemic outbreaks – an area of strength for One Health. Second, the fundamental nature of One Health is a complementary approach to medicine. Combining veterinary and human medical research creates a number of efficiencies. In the end, economics provides a solid case for investing in One Health.
One Team, One Health, One Future
Advancements in One Health are driven by researchers and clinicians in both human and veterinary medicine. While researchers and clinicians are dedicated to improving the health of people and pets, they cannot create One Health systems on their own. Funding support from government is critical, as is a reduction in barriers that are often put in place by governments themselves.
The establishment of One Health systems creates the opportunity to reduce artificial barriers between human and veterinary medicine researchers and clinicians. The diversity of a One Health initiative would generate a new knowledge base for science and medicine, and improve a wide range of health challenges including food safety, zoonotic and infectious diseases, and translational medicine.
With the tools and information created by One Health we have the opportunity to follow in the footsteps of Sir William Osler and create the next century of medicine.
LifeOmic Editor Note: Are you a clinician or researcher wanting to combine data from human and animal trials for novel treatment discovery? Check out LifeOmic’s Precision Health Cloud platform, which can integrate, index, analyze and visualize any kind of health data, whether from humans or animal research subjects.
References
- Grace et al. Mapping of poverty and likely zoonoses hotspots. Zoonoses Project 4. Report to the UK Department for International Development. Nairobi, Kenya: ILRI.
- Peiris JSM and Guan Y. Confronting SARS: a view from Hong Kong. Phil Trans R Soc Lond B. 359: 1075-1079. 2004.
- Fitton A and Brogden RN. Pimobendan. A review of its pharmacology and therapeutic potential in congestive heart failure. Drugs Aging. 1994 May;4(5):417-41.
- Asanoi H and Inoue H. Positive inotropic agents: a double-edged sword for chronic heart failure. Intern Med. 1996 Jan;35(1):63-4.
- O’Grady MR, Minors SL, O’Sullivan ML, Horne R. Effect of pimobendan on case fatality rate in Doberman Pinschers with congestive heart failure caused by dilated cardiomyopathy. J Vet Intern Med. 2008 Jul-Aug;22(4):897-904.
- Fuentes VL, Corcoran B, French A, Schober KE, Kleemann R, Justus C. A double-blind, randomized, placebo-controlled study of pimobendan in dogs with dilated cardiomyopathy. J Vet Intern Med. 2002 May-Jun;16(3):255-61.
- Summerfield NJ et al. Efficacy of pimobendan in the prevention of congestive heart failure or sudden death in Doberman Pinschers with preclinical dilated cardiomyopathy (the PROTECT Study). J Vet Intern Med. 2012 Nov-Dec;26(6):1337-49.
- Boswood A et al. Longitudinal Analysis of Quality of Life, Clinical, Radiographic, Echocardiographic, and Laboratory Variables in Dogs with Preclinical Myxomatous Mitral Valve Disease Receiving Pimobendan or Placebo: The EPIC Study. J Vet Intern Med. 2018 Jan;32(1):72-85.
- Altenberger J et al. Levosimendan in Acute and Advanced Heart Failure: An Appraisal of the Clinical Database and Evaluation of Its Therapeutic Applications. J Cardiovasc Pharmacol. 2018 Mar;71(3):129-136.
- Bridle BW et al. Potentiating Cancer Immunotherapy Using an Oncolytic Virus. Mol Ther. 2010. 18(8): 1430-1439.
- Hummel J, Bienzle D, Morrison A, Cieplak M, Stephenson K, DeLay J, Woods JP, Lichty BD, Bridle BW. Maraba virus-vectored cancer vaccines represent a safe and novel therapeutic option for cats. Sci Rep. 2017 Nov 16;7(1):15738.
- Matuszewska K et al. Combining Vascular Normalization with an Oncolytic Virus Enhances Immunotherapy in Advanced Stage Ovarian Cancer. Clin Cancer Res. 2018 Sep 11. pii: clincanres.0220.2018.
