One Health, or the idea that human health is connected to the health of animals and the environment has of late become an exciting topic of conversation globally. However, scientific literature shows the concept of One Health dates as far back as Aristotle (around 400 BC), Giovanni Maria Lancisi (1600’s) and Rudolf Virchow, a clinician in the 1800’s who coined the term ‘zoonosis’ (diseases that can be transmitted from animals to humans). Over time, the One Health concept has gradually evolved into what it represents today. Nowadays, we know that major infectious diseases including vector-borne diseases (like dengue and malaria that are passed by small insects), tuberculosis, influenza, Ebola, Zika, and other pathogens occur at the interface of people, animals and the environment.
The 2014-2016 Ebola outbreak that took many lives in West Africa will help clarify this concept. From the perspective of the virus, humans are not an ideal host for Ebola. While infected humans can spread the virus to other people, they also become very ill and often die, which significantly limits the spread of virus. Therefore Ebola requires a more ‘long term’ host than humans. This is where certain species of wild animals such as bats and deer come in; it is thought that the Ebola virus can exist in animal species, especially bats, without causing immediate harm.
The threat of Antimicrobial Resistance is a huge (and growing) problem with no clear solution in sight.
However, when virus comes into contact with the human population, for example when people hunt or touch Ebola-contaminated raw bat meat or deer meat from the wild, Ebola virus can be transmitted to human begins. Ebola virus might have been in the wild since early human history without causing much damage to humans. But due to human’s gradual encroachment into wildlife habitats (a simple example of ‘environmental event’) there is now more opportunity for interaction between humans and wild animals such as bats and other species. This has led to one of the biggest Ebola outbreaks in recent times. Similar examples can be seen in recent surge of influenza (e.g. avian influenza) and other diseases that can be transmitted between humans and animals.
In terms of One Health, there is a serious threat to human health by way of emergence of a new global phenomenon, and it is far more serious than most infectious diseases around the globe. The threat of Antimicrobial Resistance (AMR) is a huge—and growing—problem with no clear solution in sight. AMR is the collective resistance of bacterial diseases to the antibiotics (antimicrobials) used to treat them. Essentially, growing AMR means decreasing ability to treat every-day diseases. Because of this, AMR is a hot topic of discussion among health professionals, agriculture professionals, researchers, policymakers and among the interested general public in recent years. In Nepal, there is also increased interest in this issue. This is a good sign—AMR must be considered a real threat to human lives, and there is currently no antimicrobial to mitigate this threat (pun intended).
Alexander Fleming, to whom the discovery of the antibiotic penicillin is attributed, had stated long before the emergence of AMR that resistance to antibiotics was a future possibility. This was because he knew that bacteria are known to adapt to stressful situations, if given adequate time. Darwin, the famous evolutionary scientist, had already postulated about ‘survival of the fittest’ in nature. Bacterial populations also follow this phenomenon. Those that can adapt to stressful situations can thrive while others perish. And from among those that survive, a stronger population emerges. Administration of antibiotics to a person or animal with a bacterial infection is a prime example of a “stressful situation” to the bacteria. Through overuse and misuse of antibiotics, such as using them whenever one is sick instead of when an antibiotic is truly called for, humans have provided bacteria enough time and opportunity to evolve to a stage where they can either evade or counter an antibiotic attack. This is now seen in the emergence of bacterial families that are resistant to drugs (antimicrobials) used for tuberculosis, sexually transmitted diseases and many other infections in humans. The ineffectiveness of commonly used antibiotics is leading to severe medical complications and even deaths, globally.
In terms of One Health, AMR is not only a huge concern due to the use of antibiotics in humans, but also because of its use in feed of livestock and food animals, which is commonly done to promote animal growth. There is enough evidence to suggest that this may be leading to emergence of AMR bacteria in domesticated animals and bird population, shifting to humans.
In Nepal and many other countries in the world, commercial poultry and fish farming industry is increasingly using antibiotics in animal feed. Unfortunately, due to lack of adequate knowledge among the farmers, and due to lack of clear prescription practices for drug use, prophylactic antibiotic use (using antibiotics before an animal is sick) is largely uncontrolled. Handling live animals/fish and raw meat also exposes person to possible AMR bacteria, and how far and how well these bacteria spread through the environment is still largely unknown. Northern Europe, the US, Australia and many other developed countries are gradually controlling or stopping prophylactic use of antibiotics in animal agriculture for this reason. This is not something that can be implemented overnight, but given the urgency of the situation, steps should also be initiated in Nepal.
Transmission of AMR bacteria from animals to humans has been documented through research and surveillance globally. With a One Health perspective, the importance of food animals, farming techniques and our own interaction with the environment must be considered as we address the AMR threat. Not only the World Health Organization (WHO), but also the Food and Agriculture Organization (FAO) and the World Organization for Animal Health (OIE) are now focusing on AMR. This further emphasizes the importance different sectors provide to this vital issue. This collaboration is critical to initiate and support control strategies that are now being developed across the globe.
The take-home message is simple: We all live in one world, it’s the only one we have. “Health” can no longer be considered separately for humans, animals and environment. Nature doesn’t see country borders. We have one world, One Health. In this context, let’s take the issue of AMR seriously. We can no longer afford not to.
Dixit is the Program Director of Global Antibiotic Resistance Partnership-Nepal and
Nelson is a Global Health Epidemiologist with RTI International