WOAH Reports Consistent Decrease in Antimicrobial Use in Animals Globally

The World Organisation for Animal Health (WOAH) recently released a landmark report which shows encouraging progress in fighting antimicrobial resistance. According to this new analysis, global antimicrobial use in animals has declined by 13% in three years, marking a significant shift in the continuous efforts to preserve the efficacy of these critical medicines.

We must never forget that antimicrobial medicines, such as antibiotics, paved the way for better living conditions for humans and animals, protecting them from serious infections and death. Yet, today, because of their misuse and overuse in different sectors, these life-saving drugs are losing their efficacy, causing “antimicrobial resistance“.

The global authority on animal health, WOAH, has been collecting information on the use of antimicrobials in animals since 2015, publishing a report every year. From these reports emerges the steady efforts in reducing antibiotics in the animal health sector worldwide. The latest report also showcases a decline in the use of antimicrobials considered to be of critical importance for human health.

We spoke to Dr Javier Yugueros-Marcos, Head of the Antimicrobial Resistance and Veterinary Products Department, about WOAH’s actions and the reduction in veterinary antibiotic use.

Dr Yugueros-Marcos, why do you think this reduction in antibiotic use has occurred?

We have not analysed this trend’s root cause, hypothesising we can’t attribute it to one single reason. Our Global Strategy on AMR has four pillars of action: increase awareness and understanding, strengthen surveillance and research, support good governance and capacity-building, as well as encourage the implementation of our international standards. We have been working with our member countries in its deployment since 2016, and it is probably a combination of all these actions at a global, regional and national level that this decrease has occurred.

Some observations : 

  • Up to 60% of our member countries have implemented a National Action Plan to curb AMR in the animal health sector. That’s three times higher than in 2016, when the Global Action Plan on AMR was launched, including an objective to reduce the use of antimicrobials across all sectors. Thus, setting specific regulations might have had a strong influence on this.
  • There are two regions where surveillance systems are more mature, and the decrease has been consistent during the last few years. These are Europe and Asia.
    • In Europe (EU and non-EU countries), more than 70% have reported data from 2017-2019 showing a decreased antibiotic use in animals. Many of these countries have been monitoring antimicrobial quantities for more than a decade and, consequently, have been analysing their data and producing valuable reports to drive their decisions for antimicrobial use. Moreover, most of these countries are also part of the ESVAC project, which provides an overview of the EU at a national level. In the report that analysed the data for 2019, it stated that: “For the 25 countries that reported sales data to ESVAC for every year from 2011 to 2020, an overall decrease in sales of 43.2% (mg/PCU)”, which is consistent to the data that we receive at WOAH. (NB: the 2021 ESVAC report shows a 47% decrease for these countries)
    • Similar to Europe, in Asia, more than 70% of the countries providing data between 2017-2019 reported a reduction in antibiotics intended for use in animals. Most of these countries started data collecting when we launched ANIMUSE in 2015 and already have around eight years of collecting and refining their data collection systems. There is still work to be done, but we can see these countries generate national reports, analyse their data and are eager to advance to use their data analysis in decision-making quickly.
  • In other regions, such as Africa and the Americas, some countries are decreasing their quantities. This could indicate that decisions have been made based on their reports to WOAH. However, the data are scattered and are still under consolidation as their data collection systems get solid.

Moreover, we continue strengthening our awareness campaigns, as shown in our renovated web portal on AMR, including materials for professionals and concerned citizens. Finally, we continue to work closely with member countries to build technical capacities in analysing the data and decision-making, and we keep evolving our international standards in constant dialogue and exchange with our Quadripartite partners (FAO, UNEP and WHO), implementing a One Health approach.

As mentioned, this is not the consequence of a single action but the fruit of a consistent dialogue with all the key stakeholders in the animal health sector. Data collected through ANIMUSE provides evidence of the willingness of this sector to curb the global threat of AMR. We are not at the optimal level of responsible use of antimicrobials yet, but these figures encourage all of us to keep our work and progress.

Can vaccination help in reducing even more antibiotic use in livestock farming? 

The answer is simple and clear: Yes, definitely.

We could make a whole article only on this topic, but let me highlight just three examples.

  • Even though this is probably out of your article’s scope, I would like to start with one of the most outstanding examples in a sector often overlooked when discussing animal health: aquatic animals. During the 80s and early 90s, in Norway, antimicrobial use was very high in cultured Atlantic salmon due to frequent issues with cold water vibriosis (Vibrio salmonicida) and furunculosis (Aeromonas salmonicida). To face this unsustainable situation, joint efforts from producers, the government, and academic R&D initiatives led to the developing of vaccines for those diseases. Their implementation, along with improved health management, resulted in a drastic reduction in antimicrobial use: from a peak of 876 mg/kg in 1987 to 0.15 mg/kg in 2020, which is more than a 95% reduction (further details in Figure 8, p22, of this official Norwegian report).
  • Probably closer to your article scope, I’d like to highlight the case of East Coast fever, a tick-borne protozoal disease, a leading cause of calf mortality in large regions of Eastern and Southern Africa. This report published in Science in 2016 shows the positive impact of implementing and adopting vaccination strategies. The study shows a decrease in the use of antimicrobials and benefits from reducing livestock mortality and increasing milk production. In a region where 75% of the population is engaged in small-scale farming, and 80% of households get direct revenue from keeping livestock, the increased income from East Coast fever vaccination allowed them to improve childhood education and food purchases. Vaccination reduced antimicrobial use and contributed to at least 5 of the 17 sustainable development goals (i.e., poverty, hunger, quality education, life on land and gender equality). Inspiring reading I recommend you if you have not already read.
  • The third and last example I want to highlight is the 67% decline in antibiotic use on finishing pig farms when Porcine CircoVirus type-2 (PCV-2) vaccines were used in this study published in 2016. The main reason why I picked this one is because it completes the series of bacterial, parasitic and viral vaccines. The traditional paradigm is to think about developing vaccines against the agents leading to antibiotics, such as bacteria. However, antibiotic use can also be reduced by vaccination against other infectious agents than bacteria, as they improve animal health, reducing the need to use antibiotics for prevention purposes.

To this respect, it is worth mentioning two reports WOAH published in 2015 and 2018, prioritising those animal diseases for which vaccines could reduce antimicrobial use in animals. Vaccination in animal health is still not the norm, and we are currently working and advocating to strengthen research and development in this area, which is somehow orphan from funding. According to a report generated by the R&D AMR Hub in 2021, less than 10% of the total investments in R&D for AMR are used in animal health. Given the large spectrum of animal species and diseases we cover, this investment rate is not adequate to provide successful results and therefore effective implementation of animal vaccination strategies.

I hope these lines have convinced you about my simple initial answer: yes, definitely!

Is livestock the main origin of antibiotic resistance? 

One of the most common myths around AMR might motivate your question: “More antimicrobials are used in animals than in humans.

Well, the truth is that there are many more animals than humans on earth. The global weight of animals is far higher than that of humans. It is logical that the total quantity of antimicrobials used in animals exceeds that of humans. However, if you want to compare antimicrobial use in animals and humans, you should use a comparable indicator, using biomass as a point of reference instead of global weight. Only a few countries are applying this methodology to make fair estimations today. And in some cases, we can observe that the use of antimicrobials expressed in mg/kg in humans is higher than in animals.

In addition to that, we have to bear in mind that AMR is a phenomenon driven by random mutations and natural selection. Some bacteria can also share genetic material with other bacteria, increasing the spread of resistance across bacterial populations, in humans, animals, plants, and the environment. The improper use of antimicrobials greatly accelerates AMR, as these can exert selective pressure for bacteria with resistance traits to survive and thrive.  

As antimicrobials are used in humans, animals and plants, AMR cannot be attributed to just one sector. It is a cross-sectorial, One Health issue that affects all of us. As human, animal and plant health are interconnected, solutions must also arise from multisectoral cooperation. This nice report, published in 2016, provides further details about mechanisms and drivers of antimicrobial resistance across different sectors.

WOAH is working with its Quadripartite partners to expand the practice of integrated analysis worldwide. This will enable governments to make cross-sectoral evidence-based decisions, allocating resources where needed for a more responsible use of antimicrobials (i.e., vaccination campaigns, improvement of biosecurity, infection, prevention and control strategies, etc.)