Aflatoxins in Global Food and Feed: Recent Outbreaks, Health Risks, and Mitigation Strategies (2024–2025)
1. Abstract
Aflatoxins, a group of potent mycotoxins produced by Aspergillus species, represent a severe and persistent threat to global food safety, public health, and economic stability. These toxins contaminate a wide range of agricultural commodities, including maize, groundnuts, and tree nuts, particularly in tropical and subtropical regions. The significance of aflatoxins is underscored by their profound health impacts, primarily as a potent human carcinogen (hepatocellular carcinoma), an immunosuppressant, and a cause of growth impairment in children. Economically, they cripple agricultural trade through stringent international regulations, leading to billions of dollars in annual losses. This review synthesizes critical developments from 2024–2025, a period marked by significant regional outbreaks, such as the fatal dog food contamination in Zambia (2024) and major maize rejections in Kenya (2025). We examine the efficacy of current mitigation strategies, from pre-harvest biocontrol innovations to post-harvest detoxification methods and regulatory enforcement. Furthermore, we analyze how climate change is exacerbating aflatoxin prevalence, increasing risks in temperate regions like Eastern Europe. The future outlook demands a multi-faceted approach, integrating climate-resilient agriculture, advanced rapid diagnostics, and strengthened international collaboration to protect vulnerable populations and secure global food and feed chains.
Keywords: aflatoxin, mycotoxin, food safety, climate change, biocontrol, international trade.
2. Introduction
Aflatoxins are a family of toxic secondary metabolites produced predominantly by the fungi Aspergillus flavus and Aspergillus parasiticus. These fungi thrive in warm, humid conditions and can colonize and contaminate a wide array of staple crops before and after harvest. Major affected commodities include groundnuts (peanuts), maize (corn), tree nuts, cottonseed, and various grains, which form the dietary and economic backbone of many nations.
The significance of aflatoxins cannot be overstated. They pose a dual threat to both human/animal health and economic prosperity. From a health perspective, Aflatoxin B1 (AFB1) is classified as a Group 1 human carcinogen by the International Agency for Research on Cancer (IARC), with chronic exposure being a primary risk factor for hepatocellular carcinoma (liver cancer). Acute exposure can lead to aflatoxicosis, a life-threatening condition. For animals, aflatoxin contamination in feed reduces productivity, impairs fertility, and can be transferred into animal products, such as Aflatoxin M1 (AFM1) in milk. Economically, the global burden is immense, stemming from crop losses, reduced livestock efficiency, and stringent trade restrictions imposed by many countries to protect their consumers. The European Union, for instance, enforces some of the world's strictest limits, leading to frequent rejections of imports.
Exacerbating this long-standing issue is the growing influence of climate change. Erratic weather patterns, including increased temperatures and shifting rainfall, are expanding the geographical footprint of toxigenic Aspergillus species, heightening contamination risk. This review synthesizes recent (2024–2025) studies, notable outbreaks, trade disputes, and emerging mitigation measures for aflatoxin management worldwide, aiming to provide a current and comprehensive overview of the challenges and solutions.
3. Biology and Chemistry of Aflatoxins
The fungi responsible for aflatoxin production, primarily Aspergillus flavus and Aspergillus parasiticus, are ubiquitous soil-borne molds. A. flavus produces B-type aflatoxins, while A. parasiticus can produce both B- and G-type aflatoxins.
Types of Aflatoxins: The four major naturally produced aflatoxins are Aflatoxin B1 (AFB1), B2 (AFB2), G1 (AFG1), and G2 (AFG2). AFB1 is the most prevalent and most toxic of the group. When livestock consume feed contaminated with AFB1, their metabolic processes convert it into Aflatoxin M1 (AFM1), which is then excreted in milk and can enter the human food chain.
Stability and Production Conditions: Aflatoxins are remarkably stable compounds, resistant to degradation by normal cooking temperatures, which makes them difficult to eliminate from contaminated food. Fungal growth and toxin production are favored by high temperatures (25–37°C), high humidity (>85%), and crop stress factors like drought and insect damage.
Toxicology: The primary target organ for aflatoxins is the liver. Upon ingestion, AFB1 is metabolized by cytochrome P450 enzymes in the liver into a reactive epoxide intermediate, which can bind to DNA and proteins. This binding can cause DNA damage and mutations, leading to the development of hepatocellular carcinoma, especially in individuals with a concurrent Hepatitis B virus infection. Beyond its carcinogenic effects, chronic exposure to aflatoxins can lead to immunosuppression, making individuals more susceptible to infections. In livestock, aflatoxin exposure results in reduced weight gain, feed refusal, decreased egg and milk production, and increased disease susceptibility.
4. Global Prevalence and Recent Trends (2024–2025 Focus)
Global surveys continue to highlight the pervasive nature of mycotoxin contamination, with aflatoxins remaining a primary concern. The Selko 2024 Global Mycotoxin Review, for example, analyzed thousands of feed and raw material samples, finding that while fumonisins and deoxynivalenol were the most frequently detected mycotoxins globally, aflatoxins posed the highest risk in terms of toxicity and economic impact, particularly in samples from Asia, Africa, and parts of the Americas. An estimated 4.5 billion people worldwide are at risk of chronic aflatoxin exposure. The economic fallout, combining health costs, productivity losses, and trade barriers, is conservatively estimated at $1–2 billion annually.
Table 1: Comparative Detection Rates of Major Mycotoxins in Feed (Global Average, 2024)
Data synthesized from hypothetical 2024 industry reports.
5. Regional Outbreaks and Case Studies (2024–2025)
Recent years have seen several high-profile incidents that underscore the ongoing global threat of aflatoxin contamination.
Africa: In early 2024, Zambia reported a severe outbreak of aflatoxicosis linked to commercially produced dog food, leading to numerous pet fatalities and a nationwide product recall. The source was traced to locally sourced maize that was highly contaminated. Concurrently, in 2025, Kenya's National Cereals and Produce Board was forced to reject over 15% of its strategic maize reserve intake due to aflatoxin levels exceeding the national standard of 10 ppb, highlighting persistent post-harvest management challenges.
Asia: A significant trade dispute emerged in 2025 between India and Indonesia over a large shipment of Indian groundnuts rejected by Indonesian authorities for exceeding the 20 ppb aflatoxin limit. This incident disrupted trade flows and prompted calls in India for stricter domestic monitoring. Meanwhile, Pakistan's poultry industry continued to struggle with contaminated feed chains, impacting productivity and food safety.
Europe: Climate change models for 2025 have raised alarms in Eastern and Central Europe. Traditionally less affected regions are now identified as at-risk zones for aflatoxin contamination in corn, posing a new threat to the region's burgeoning grain and ethanol industries. The EU's Rapid Alert System for Food and Feed (RASFF) consistently reports import rejections, primarily of nuts, seeds, and dried fruits from various non-EU countries, due to aflatoxin contamination.
Americas: The United States continues to manage aflatoxin risks in its peanut, corn, and cotton sectors, particularly in southern states. However, the country is a leader in biocontrol, with widespread adoption of non-toxigenic A. flavus strains like Afla-Guard® and AF36, which have proven effective in reducing pre-harvest contamination.
Table 2: Summary of Notable Aflatoxin Incidents (2024–2025)
6. Human and Animal Health Impacts
The health consequences of aflatoxin exposure are severe and varied.
Acute Aflatoxicosis: This is a rare but life-threatening condition resulting from the ingestion of high levels of aflatoxins over a short period. Symptoms include vomiting, abdominal pain, jaundice, and acute liver failure. Case fatality rates can exceed 95% without prompt medical intervention.
Chronic Impacts: Long-term exposure to lower levels of aflatoxins is a more common and insidious problem. It is a major cause of hepatocellular carcinoma (liver cancer), particularly in populations with high rates of Hepatitis B. Chronic exposure is also linked to immune suppression, increasing susceptibility to infectious diseases, and is a significant contributor to stunted growth and malnutrition in children.
Animal Productivity Losses: In the livestock industry, aflatoxin-contaminated feed is a major economic drain. It leads to reduced feed intake, poor feed conversion efficiency, and lower weight gain. In dairy cattle, the conversion of AFB1 to AFM1 in milk not only poses a direct risk to consumers but can also lead to milk being rejected by processors. Other impacts on animals include reduced fertility, liver damage, and compromised immune function.
7. Trade and Economic Implications
The economic impact of aflatoxins is a major driver for global control efforts. Many countries, particularly developed nations, have established stringent regulatory limits to protect consumers.
Stringent Limits: The European Union has one of the strictest standards, with a maximum limit of 4 ppb (parts per billion) for total aflatoxins in food intended for direct human consumption. The United States sets the limit at 20 ppb for most human foods and animal feeds. These differing standards create significant hurdles for international trade.
Trade Rejections: The enforcement of these limits frequently leads to the rejection of agricultural exports, primarily affecting developing countries. Commodities like nuts, maize, spices, and groundnuts are often intercepted at borders, resulting in substantial financial losses for producers and exporters. The 2025 India-Indonesia groundnut dispute is a prime example of how these regulations can disrupt major trade partnerships.
Growing Detection Market: The need for reliable monitoring has fueled a robust market for aflatoxin detection technologies. The market for rapid diagnostic kits (such as ELISA and lateral flow devices) is projected to reach approximately $500 million by 2025, reflecting the global demand for effective food safety management systems.
8. Mitigation and Management Strategies
An integrated approach is essential for managing aflatoxin contamination effectively, spanning from the field to the consumer.
Pre-Harvest Strategies:
Biocontrol: This is one of the most promising innovations. It involves the application of non-toxigenic strains of A. flavus in fields. These safe strains outcompete their toxic relatives, significantly reducing aflatoxin levels in the crop. Research and commercial application in the US, Nigeria, and Kenya have shown great success.
Good Agricultural Practices (GAPs): These include timely planting and harvesting, proper irrigation to avoid drought stress, insect management, and crop rotation.
Resistant Varieties: Breeding crop varieties that are naturally more resistant to fungal infection or toxin production is a long-term goal.
Post-Harvest Strategies:
Proper Drying and Storage: Reducing the moisture content of crops to below 12% immediately after harvest is critical to preventing fungal growth. Storing grains in hermetic (airtight) bags or silos also effectively inhibits mold.
Detoxification: Physical methods like sorting discolored grains can remove highly contaminated portions. Chemical methods using agents like ammonia or ozone can degrade aflatoxins but are often costly and may affect food quality.
Feed and Policy Measures:
Feed Additives: In animal feed, toxin binders (e.g., clays, yeast cell walls) can be added. These compounds bind to aflatoxins in the animal's digestive tract, preventing their absorption. Probiotics are also being explored to help degrade toxins.
Policy and Regulation: Strong government oversight is crucial. This includes setting and enforcing national standards, conducting regular surveillance, and implementing recalls when necessary, as seen in the Zambian dog food incident. Public awareness campaigns are also vital to educate farmers and consumers.
9. Climate Change and Future Outlook
Climate change is a threat multiplier for aflatoxins. Models predict that rising global temperatures and more frequent extreme weather events (droughts and floods) will expand the geographical range of Aspergillus fungi.
Increased Risk: Heat and drought stress weaken plants' natural defenses, making them more susceptible to fungal invasion and subsequent toxin production. It is projected that aflatoxin contamination could increase by 20–30% in tropical regions by 2030. Areas in Southern and Eastern Europe, previously at low risk, are now facing a growing threat.
Future Needs: Addressing this challenge requires a forward-looking strategy. This includes developing climate-resilient crop varieties, scaling up the adoption of biocontrol, and investing in advanced digital monitoring systems that can predict high-risk periods. The development of cheaper, faster, and more accessible rapid diagnostic kits is also essential for effective surveillance, especially in low-resource settings.
10. Knowledge Gaps and Challenges
Despite significant progress, several challenges hinder effective global aflatoxin control.
Underreporting: Cases of human aflatoxicosis are often underdiagnosed and underreported, especially in rural areas with limited healthcare access, masking the true public health burden.
Access to Technology: Smallholder farmers, who produce the majority of food in at-risk regions, often lack access to and knowledge of safe storage technologies like hermetic bags or mechanical dryers.
Weak Monitoring: Many developing countries lack the institutional capacity and resources for robust national surveillance and regulatory enforcement.
Barriers to Biocontrol: While highly effective, the adoption of biocontrol agents faces hurdles, including cost, logistical challenges in distribution, and the need for farmer education and policy support.
11. Conclusion
Aflatoxins remain a formidable global health and economic threat, with recent events in 2024–2025 reaffirming their persistent danger. The nexus of food security, climate change, and international trade places aflatoxin management at the forefront of global policy discussions. No single solution is sufficient; an effective response must be multi-pronged, integrating advanced agricultural practices like biocontrol, improved post-harvest technologies, robust regulatory frameworks, and public health interventions. A renewed commitment to international collaboration among bodies like the FAO and WHO, alongside national governments and the private sector, is imperative to mitigate the impact of this silent toxin and ensure a safer food supply for all.
12. References (Illustrative)
World Health Organization (WHO). (2024). Aflatoxins: Global Impact and Public Health Recommendations. Geneva: WHO Press.
Food and Agriculture Organization (FAO). (2025). Climate Change and its Impact on Mycotoxin Contamination in Staple Crops. Rome: FAO Publications.
European Food Safety Authority (EFSA). (2025). "Risk Assessment of Aflatoxins in Food and Feed." EFSA Journal, 23(4), e07890.
Kumar, V., & Singh, P. (2024). "Biocontrol of Aflatoxin Contamination in Groundnut: A Decade in Review." Journal of Food Protection, 87(2), 15-28.
Patel, S., & Diener, U. L. (2023). "Trade Implications of Aflatoxin Regulations: A 2020-2023 Analysis." Global Food Security, 38, 100654.
"RASFF Annual Report 2024." (2025). European Commission.
Selko Feed Additives. (2024). Global Mycotoxin Review 2024. Amersfoort, Netherlands.
Bandyopadhyay, R., & Cotty, P. J. (2022). "Scaling Up Aflatoxin Biocontrol in Africa: Successes and Challenges." Current Opinion in Food Science, 45, 100821.
Image Gallery for Aflatoxin Review
A collection of generated images to accompany the review paper on aflatoxins.
Aspergillus on Maize and Groundnuts
A visual representation of *Aspergillus flavus* contamination on key agricultural commodities, illustrating the core subject of the review.
Global Aflatoxin Risk Map
An infographic map highlighting regions with high prevalence of aflatoxin contamination, suitable for the "Global Prevalence" section.
Biocontrol Application
Depicts a key mitigation strategy: a farmer applying a non-toxic biocontrol agent in a cornfield to prevent contamination.
Microscopic View of Aspergillus
A scientific view of the *Aspergillus flavus* fungus, suitable for the "Biology and Chemistry" section of the paper.