I. Article Abstract

The World Health Organisation (WHO) warns that antimicrobial resistance (AMR) has become “one of the top 10 […] public health threats facing humanity.”[1] Medical practitioners’ current arsenal of effective antibiotics is quickly diminishing. And while the World Health Assembly launched a global action plan in 2015 to tackle the issue among human populations, equivalent high-level reports examining antibiotic overuse and misuse among animals, particularly domesticated species, are less prolific. However, that does not mean that topical research and subsequent pharmaceutical regulation is any less important. As the Hong Kong Centre for Health Protection (CHP) explained on its ‘Antimicrobial Resistance FAQ’ page; “AMR has no respect for borders and direction and can be transmitted in a bi-directional manner from animals to humans and vice versa”[2].

This report opens with a general analysis of the use of human antibiotics to treat zoonotic conditions. It then considers how antibiotic misuse and overuse in both commercial and domestic sectors continues to contribute to the expansion of AMR. Particular emphasis will be placed on practices not normally encompassed by official statistical reports and policies. To close, a regulatory roadmap will be proposed with the aim of avoiding this imminent public health crisis.

 

II. Human Antibiotics and Animals

Broad-spectrum antibiotics generally do not discriminate between the organisms they are deployed to treat. Their primary function remains the same; killing or stifling the development of certain infectious bacteria. That being said, not all antibiotics are prescribed equally, as some are more effective in either human or animal hosts. According to the FDA, “animal drugs are often highly concentrated because they are used for large animals like horses and cows, which weigh a lot more than we do.”[3] Further to this, mismatching antibiotics with their target species heightens the possibility that side effects will manifest during the course of treatment. For example, several patients were hospitalised during the recent COVID-19 pandemic after self-medicating for the virus with Ivermectin, an anti-parasitic medicine used to de-worm livestock

The dissemination of misinformation, such as that human antibiotics ‘work better’ than veterinary drugs, has been fuelled by unfettered access to loosely regulated internet forums and social media sites.[4]

III. Sources of Antimicrobial Resistance in Animals

Human methodology and attitudes towards rearing and sustaining animals have hampered efforts to control the spread of resistant microbes throughout fauna populations. The agriculture industry is a primary facilitator of AMR due to excessive antibiotic use by farmers to ensure maximum growth of livestock destined for slaughter and sale, and prevent sicknesses promoted by the stressful and unhygienic conditions in which animals are often kept. This link in the AMR chain will be briefly touched upon, but the following section will mainly highlight smaller-scale actions routinely dismissed or overlooked by state reports on antibiotic use as statistically insignificant. While many of these behaviours are well-intentioned or country-specific, they nonetheless expedite the grave global consequences of AMR.

           

A. Agriculture and Large-Scale Farming

Demographic shifts and wealth redistribution in recent centuries has placed an unprecedented level of demand for animal products upon the farming industry. A combination of economic greed and desire to meet supply targets has resulted in compromises to production systems; manifesting in the form of overcrowded enclosures and artificial growth stimulation tactics. As a result, farmers are left to determine how to negate the risks emerging from these practices, namely mass illness and death of livestock. The answer for many has been prophylactic antibiotic use, fostering a damaging culture of ‘compensation’ for the poor conditions they choose to perpetuate.

The more antibiotics that are fed to animals reared for consumption, the more antibiotics humans will inevitably ingest. This issue has been recognised in most jurisdictions, and many have mandated annual reporting on antibiotic use by large-scale farming operations. Public education has also played a fundamental role in encouraging consumers to choose antibiotic and hormone-free animal products where possible.

However, integrated impact reports detailing the effect of AMR in both animals and humans, as regularly produced by the governments of some countries including Canada, the UK, Denmark and the Netherlands, are notably absent from the public health agenda of many large trade hubs, including the United States of America and China.[5] Researchers from several international institutions studying the implications of ‘Antibiotic governance and use on commercial and smallholder farms in eastern China’ reached the preliminary conclusion that “optimizing antibiotic use in animal agriculture is critical for tackling AMR from a [WHO] One Health perspective.”[6]

           

B. Smallholding and Domestic Antibiotic Use

The same report found that; “smallholders are under-regulated due to a lack of resources and assumptions about their marginal role as food safety governance targets.“[7] Small-scale and backyard farming is common practice among lower-income rural communities with limited access to regional towns. Individuals within this demographic might also face obstacles receiving professional veterinary care due to their remoteness and financial position. Some smallholders therefore “resort to [using] human antibiotics for the treatment of backyard animals.”[8]

In 2014, Ugandan farmers went one step further, administering HIV drugs to swine and poultry to ‘fatten them up’ quickly in preparation for market sale. This discovery ignited massive public health concerns that patients needing life-saving treatment in the future, such as the 1.4 million Ugandans currently living with HIV/AIDS, would not respond to anti-retroviral medicines.[9] The requirements for food markets where “individual farmers sell products on a stall directly to customers” are normally “not standardised,”[10] a factor which likely contributed to the scandal proceeding unnoticed for so long.

Rampant administration of prophylactic antibiotics to animals is harmful for both humans and animals. In Hong Kong, a salient example is that medicine is commonly fed to ornamental fish prior to display in locations such as Mong Kok’s Goldfish Market to ensure they survive long enough to be sold onwards. Yeung et al. (2022) published an inaugural report on the issue in Hong Kong, finding that the carrier water from fish sold by merchants from all five stores tested was saturated with antibiotic medicine.[11] Many fish will become sick and die just a few days after sale, still suffering the effects of the unsuitable and distressing conditions they were forced to endure. Similar patterns have been identified in pet store kittens and puppies.[12] Having developed resistance to the medicines needed for recovery, these animals become unnecessary victims of this callous trade.

Veterinarians have also reported instances of human antibiotics being administered to domestic pets by their owners. Often carried out in good faith, and seen as an ‘economical use’ for excess medicine stocks in the home, the practice poses a danger to pets who may only require a fraction of the dosage prescribed to their human counterparts. In Hong Kong, a culture of antibiotic over-prescription in GP clinics and hospitals is pervasive, and likely exacerbates this aspect of the AMR issue.[13]

 

IV. Solutions

Education is undoubtedly at the core of reform. Helping individuals understand how antibiotic overuse and misuse can affect their personal health, public health, and that of animals, and teaching responsible antibiotic usage, will hopefully encourage a shift in behaviour. All sectors of society will ultimately benefit from the dissemination of such information; whether presented to school-age children under an umbrella curriculum of respect for animal welfare, or to those in older age brackets through government-backed community outreach projects.[14]

Additionally, tighter regulations should be implemented regarding access to, and the disposal of, antibiotic medicines. Covert agents from the aforementioned study in eastern China[15] expressed concern about the ease with which they were able to purchase antibiotics over the counter at local veterinary drug and feed stores. The culture of antibiotic over-prescription which currently clouds Hong Kong’s medical sector must also be subject to scrutiny and review, and safe disposal points for excess medicines established. Earlier this year, pharmacies Mannings and JCPI Tai Ping Shan launched a joint venture trialling a system for medicine collection and secure disposal. However, the programme was short-lived and restricted in scope, only operating in twenty six chosen Mannings stores across Hong Kong. There is no indication as to whether the trial will be adopted throughout the territory. Hong Kong can learn from other countries running successful pharmacy-based medicine collection schemes, such as the United Kingdom.[16]

Streamlining the feedback system of reporting and policymaking is also essential to curb the spread of AMR. It has been shown that smallholder farms and market stalls can still act as reservoirs for the development of AMR, therefore owners should be mandated to provide regular data on antibiotic use to authorities. This goal can be achieved via comprehensive surveillance programmes and frequent inspections.

 

V. Conclusions

The escalating threat of antimicrobial resistance (AMR) demands urgent, comprehensive action on a global scale. Despite substantial efforts directed at human antibiotic use, the critical issue of antibiotic overuse and misuse within the animal domain, both commercial and domestic, remains relatively uncharted.

This report has shed light on the indiscriminate use of antibiotics in animals and its perilous implications for human health. From large-scale farming operations to smallholding practices, the unchecked administration of antibiotics perpetuates AMR, blurring the boundaries between species and amplifying the crisis.

Addressing this public health menace necessitates multifaceted solutions. Education, regulation, and enhanced reporting mechanisms are pivotal to the battle against AMR. Enforcing stringent regulations to govern antibiotic access, disposal, and prescribing practices is vital. Moreover, fostering transparent feedback systems, gathering essential data on antibiotic use, and promoting responsible agricultural and animal husbandry practices will collectively contribute to curtailing the spread of AMR.

Only through a concerted, multidimensional effort can we hope to preserve the efficacy of antibiotics and safeguard the health of both humans and animals.

Courtesy of: Saskia Sinha

References

[1] https://www.who.int/news-room/fact-sheets/detail/antimicrobial-resistance

[2] https://www.chp.gov.hk/files/pdf/amr_faqs_eng.pdf

[3] https://www.fda.gov/consumers/consumer-updates/why-you-should-not-use-ivermectin-treat-or-prevent-covid-19

[4] https://doi.org/10.3390/antibiotics11101342

[5] https://www.nrdc.org/bio/david-wallinga-md/new-data-animal-vs-human-antibiotic-use-remains-lopsided

[6] https://doi.org/10.3389/fvets.2023.1128707; see more on One Health here - https://www.who.int/news-room/questions-and-answers/item/one-health

[7] https://doi.org/10.3389/fvets.2023.1128707

[8] https://doi.org/10.3389/fvets.2023.1128707

[9] https://www.bbc.com/news/world-africa-66744520

[10] https://doi.org/10.3389/fvets.2023.1128707

[11] https://pubmed.ncbi.nlm.nih.gov/36547470/#:~:text=The%20use%20of%20antibiotics%20in,the%20situation%20in%20Hong%20Kong

[12] https://www.scientificamerican.com/article/pet-store-puppies-blamed-for-drug-resistant-infections/

[13] https://www.scmp.com/news/hong-kong/health-environment/article/2102072/hong-kong-doctors-asked-report-antibiotics-use; https://www.scmp.com/magazines/post-magazine/short-reads/article/2112208/why-do-hong-kong-doctors-overprescribe-common; https://www.wsj.com/articles/SB97320807273563833

[14] Community outreach projects can manifest in numerous ways, for example public seminars,Town Hall discussions, and the distribution of informational leaflets.

[15] https://doi.org/10.3389/fvets.2023.1128707

[16] https://cpe.org.uk/national-pharmacy-services/essential-services/disposal-of-unwanted-medicines/#:~:text=Community%20pharmacy%20owners%20are%20obliged,from%20pharmacies%20at%20regular%20intervals