We need effective antimicrobial drugs to treat and prevent infections not just in humans, but also in animals. Worldwide, it’s estimated that twice as many antibiotics are used in food production (particularly, intensive rearing of livestock) than to treat infections in humans3. Therefore, as AMR increases year on year, this compromises not only human health but also our ability to produce food. Combine this with the increasing global population, expected to reach around 10 billion by 20504, it quickly becomes apparent how important it is to safeguard the efficacy of our current antimicrobials whilst new ones are being designed and brought to market (a slow, arduous and generally inefficient process2).
A further concern is that antimicrobials are also emerging environmental pollutants. As discussed in a previous blog, natural water systems are the final destination for most antimicrobials, as they do not get fully broken down in the human or animal body and pass through sewage treatment plants or runoff from farmland into the environment, still retaining their biological activity5. A growing body of research6 has demonstrated that even very low concentrations of antibiotics, similar to those that can be measured in the environment, can lead to increases in AMR. Human and animal wastes that enter the environment also contain antimicrobial resistant organisms. The presence of these organisms combined with the presence of antimicrobials creates a potential breeding ground for the development and emergence of AMR. Environmental AMR can find its way back into humans and animals through numerous exposure routes, for example, through occupational exposure7, the food chain8, and even recreational use of outdoor spaces9,10.
Given how AMR and antimicrobials move between environments, it’s surprising that until recently, humans, animals and the environment were each considered in isolation with regards to AMR. However, the One Health approach11 recognises the interconnectedness of these different sectors and that focusing on one area alone would be insufficient for addressing the problem. For example, reducing the use of antimicrobials in humans only would not stop AMR, if use in agriculture continued to increase and humans were infected with AMR organisms through the food chain or through occupational exposure on farms.
There is also concern regarding how AMR may change or influence other global crises, like climate change. For example, higher environmental temperatures have been found to be associated with a higher prevalence of AMR pathogens12. More frequent droughts, floods or other natural disasters resulting from climate change that increase disease transmission and compromise food security could also mean that we need effective antimicrobials even more in the future. These examples support the ‘Planetary Health’ agenda – that the long-term health of humans is dependent on the health of the planet13.
Interdisciplinary approaches are needed to combat AMR across all One Health sectors, to protect human health, animal health, environmental health and the global economy. Reassuringly, this is gaining traction in national and international policy, being advocated for by the World Health Organisation14 and United Nations Environment Programme15, for example. However, we need to move beyond advocacy toward action if we are to avert the ‘silent pandemic’ of AMR.
If you would like to learn more about ‘A One Health Perspective on AMR’, consider joining the new CPD course being offered by the University of Exeter, starting virtually November 2022. Course details are here.