If the use of antibiotics in Southeast Asian livestock farming is not restricted, the world could be left defenseless in the face of the next global pandemic, warn researchers at RMIT University.
RMIT’s cautionary statement came in the form of a scientific review that looked at the twin issues of veterinary drug residues in livestock and antimicrobial resistance (AMR) in livestock pathogens in the context of Southeast Asia. The focus on Southeast Asian livestock farming is its relevance to Australia, where RMIT University is based, as Australia and Southeast Asia have strong economic ties; but also its relevance to the rest of the world, as Asia is a hotspot of AMR in animals, with Southeast Asia being an epicentre, according to the researchers.
Southeast Asia is a major producer of livestock. According to the Food and Agriculture Organization of the United Nations (FAO), the region is home to more than 2.9 billion chickens, 258 million ducks, 7 million cattle, 15.4 million buffalo, 77.5 million pigs, 13.7 million sheep and 30.6 million goats. Globalization has led to international trade in meat, increasing the opportunities for the spread of AMR worldwide.
AMR is a known threat to global public health and has been recognized by the World Health Organization (WHO) as one of the ten greatest health challenges facing humanity in the 21st century.st Century. According to some reports, drug-resistant infections will cause 300 million premature deaths worldwide by 2050, surpassing the number of deaths from cancer.
Currently, over 700,000 people die each year from antimicrobial resistance.
Intertwined but different problems: drug residues versus drug resistance
In their study, the RMIT researchers stress the importance of distinguishing between the problems of antibiotic resistance and veterinary drug residues in animal products so that policymakers and industry can develop appropriate measures to combat residue and resistance problems in Southeast Asia. The overuse of antibiotics in livestock farming – for example, to promote growth – is one of the main causes of the rise in antibiotic resistance and the presence of residues in animal foods.
AMR occurs when pathogens are exposed to a drug and develop resistance to it. On farms, the presence of antibiotics in food, soil, wastewater and animal waste can contribute to the development of this resistance. Resistant bacteria in farm animals can be transmitted to humans through the food chain or through direct contact.
Residues in livestock are chemicals that remain in animal tissues or products after livestock have been exposed to or administered those substances. Among other human health risks, consumption of animal products containing antimicrobial residues can result in the transmission of antibiotic-resistant pathogens to humans.
The presence of drug residues in food is much easier to measure than antibiotic resistance – and therefore to regulate, as many countries have legal maximum residue levels of various chemicals in food. Although there is growing scientific evidence linking high drug residues in livestock to high antibiotic resistance, the link is complex and can be influenced by a variety of factors, resulting in different relationships between resistance and residues. The RMIT researchers explain that it is important to clarify this link in order to effectively address the threat of antibiotic resistance.
Southeast Asia’s unique residue and resistance challenges and recommendations for combating them
In some countries, such as Australia, antibiotic use is much more strictly regulated than in others, such as in Southeast Asia, the RMIT researchers claim. In Southeast Asian countries, factors such as the prevalence of small-scale farming, limited veterinary services and the importance of informal food markets make it difficult to implement strict antibiotic regulatory measures and AMR surveillance systems.
In Southeast Asia, several studies have demonstrated multidrug resistance in chickens, ducks and pigs. This includes resistance to classes of antibiotics used to treat humans, such as fluoroquinolones and third-generation cephalosporins, as well as to the all-important colistin.
Southeast Asian governments have recognised the problem of antibiotic resistance (AMR) in local livestock farming and have taken some steps to regulate the use of antimicrobials. However, as the problem is urgent, researchers at RMIT have recommended six ways in which Southeast Asian policymakers can address the problem of antibiotic resistance (AMR) and residues in livestock:
- Recognize the difference between residues and resistance to address the challenges of antibiotic resistance with appropriate measures
- Work together regionally and develop tailored strategies to address disease outbreaks, environmental issues, residue levels and AMR
- Implement country-specific awareness campaigns, thorough monitoring of residues and resistance, appropriate regulations and responsible use of antimicrobials to reduce the risk of resistance
- Promote international cooperation and initiatives to comprehensively combat resistance, ensure a common front against backlogs and resistance
- Strengthening public health systems and prevention
- Promote innovation and research in alternative antimicrobial solutions, sustainable agricultural practices and advanced diagnostics to stay ahead of evolving challenges.
“There is a threat of a major pandemic in the form of AMR,” said veterinarian and RMIT Professor of Life Sciences Rajaraman Eri, Ph.D., MVSc., who co-authored the report. “We will face a situation globally where antibiotics will run out. That means we will no longer be able to treat infections.” The full article, which can be found in the International Journal of Food Science and Technologycan be accessed here.
