Review Article - Journal of Food Nutrition and Health (2021) Volume 4, Issue 4
Communicational strategies to prevent mycotoxins exposure and improvecommunity health in developing countries
Department of Food and Nutritional Sciences, Wollega University, Shambu, Ethiopia
- Corresponding Author:
- Gesessew Kibr Department of Food and Nutritional Sciences, Wollega University, Shambu, Ethiopia E-mail: [email protected]
Accepted date: 12th May, 2021
Citation:Gesessew Kibr. Communicational Strategies to Prevent Mycotoxins Exposure and Improve Community Health in Developing Countries. J Food Nutr Health 2021;4(4):1-5
Well known within the agricultural community, mycotoxinshave been studied for over forty years due to their widespread occurrence and their significant impact on crops [1-4]. Aflatoxins are toxic secondary metabolites produced by fungi. Mycotoxins are the most potent and potentially lethal metabolite and are a known human carcinogen. Mycotoxins can affect a wide range of commodities including cereals, oilseeds, spices, and tree nuts as well as milk, meat, and dried fruit. The major sources of exposure are maize and groundnuts as these are the foods that are most susceptible to contamination and consumed in the greatest amounts.
The greatest risk for health impact lies within developing countries located in tropical regions, which rely on these commodities as their staple food source. Food insufficiency and lack of diversity substantially contribute to the susceptibility of individuals and communities to Mycotoxins. Mycotoxins have been recognized as significant contaminants by the agricultural production community since the 1960’s and control strategies have mostly eliminated harmful exposures in developed countries . The application of these strategies in developing countries is difficult, given differences in technology, agriculture, and trade practices, as well as other issues contributing to occurrence of aflatoxins and incidence of exposure. Consequently, over 5 billion people in developing countries worldwide are at risk of chronic exposure to mycotoxins through contaminated foods .
Mycotoxins associated health effects pervade the developing world despite the fact that these effects could be mitigated or prevented with the current state of agricultural knowledge and public health practice. Outbreaks of acute mycotoxins poisoning are a recurrent public health problem. In 2014, one of the largest, most severe mycotoxins outbreaks occurred in Developing countries followed by another outbreak in 2005 .
Given that diseases in the developing world often go unreported, the developingcountries outbreaks are likely to be an underestimation of the problem; furthermore, the burden of disease attributable to chronic aflatoxin exposure (e.g. hepatocellular carcinoma, impaired growth, immune suppression) remains undefined. These outbreaks emphasize the need to quantify and control mycotoxins exposure in developing countries and highlight the potential role of public health. Contamination can occur at any stage of food production from pre-harvest to storage . Factors that affect mycotoxins contamination include the climate of the region, the genotype of the crop planted, soil type, minimum and maximum daily temperatures, and daily net evaporation [7-11].
Mycotoxins contamination is also promoted by stress or damage to the crop due to drought prior to harvest, insect activity, poor timing of harvest, heavy rains at harvest and post-harvest, and inadequate drying of the crop before storage [12-15]. Humidity, temperature, and aeration during drying and storage are also important factors. The effects of mycotoxins on animal health have been observed in many species for over forty years beginning with the documentation of Turkey X disease in 1960. The primary target of mycotoxins is the hepatic system. Acute effects include hemorrhagic necrosis of the liver and bile duct proliferation while chronic effects include hepatocellular carcinoma (HCC). In animals, suppression of immunity, growth retardation, and increased susceptibility to infectious disease due to mycotoxins exposure is well documented. The effects of mycotoxins on humans, as with animals, are dependent upon dosage and duration of exposure. Acute exposure can result in mycotoxins, which manifests as severe, acute hepatotoxicity with a case fatality rate of approximately 25%.
Early symptoms of hepatotoxicity from aflatoxicosis can manifest as anorexia, malaise, and low grade fever. Acute high level exposure can progress to potentially lethal hepatitis with vomiting, abdominal pain, jaundice, fulminant hepatic failure, and death. Outbreaks of acute mycotoxins are a recurring public health problem throughout the world [6,16]. Hepatocellular carcinoma (HCC) as a result of chronic exposure has been well documented, generally in association with hepatitis B virus or other risk factors [17-20]. The International Agency for Research on Cancer (IARC) first recognized aflatoxins as carcinogenic in 1976 and has subsequently reaffirmed naturally occurring mixtures of aflatoxins and aflatoxin B1 as Group 1 carcinogens (carcinogenic to humans). Additional effects of chronic exposure have not been widely studied but are thought to include immunologic suppression, impaired growth, and nutritional interference.
Mycotoxins Concerns in Developing Countries
Although a few studies have provided estimates of daily exposure to mycotoxins during non-outbreak periods, more information is needed concerning baseline levels of chronic exposure for vulnerable populations. This would allow for a better quantification of the health risks associated with chronic exposure and for a better estimate of the level of mycotoxins exposure necessary to trigger an outbreak. Such knowledge will enable the public health community to understand health effects associated with chronic exposure and allow for the evaluation of future public health and agricultural interventions (Table 1).
|Pre-Harvest||Timing of planting; Crop planted; Genotype of seed planted; Irrigation; Insecticides; Competitive exclusion; Timing of harvest;|
|Post-Harvest: Drying and Storage||Hand sorting; Drying on mats; Sun drying; Storing bags on wooden pallets or elevated off ground; Insecticides; Rodent control;|
|Post-Harvest: Food Preparation||Hand sorting; Winnowing; Washing; Crushing and dehulling; Nixtamalization; Acidification; Chemoprotectant; Enterosorption;|
Table 1: Interventions for Preventing or Reducing Aflatoxin Exposure.
Public Health Risks Associated with Consumption of Mycotoxins
In this case control study subjects diagnosed with endometriotic lesions by surgery or magnetic resonance were defined as cases (n=59) . Controls (n=59) had no visible ectopic endometrium sites during surgical, that was performed for the treatment of benign diseases, such as ovarian, myoma or other reasons. Women previously diagnosed with adenomyosis, pregnant or breastfeeding; on corticosteroids for autoimmune diseases and malignancies; and those diagnosed with other conditions that could interfere with anthropometric evaluation (anasarca, ascites, lower and upper limb edema, and limb amputation), were excluded from this study. The present study focused on main symptoms of endometriosis, such as dysmenorrhea, chronic pelvic pain, deep dyspareunia and infertility . Measurement of body weight and height (for the calculate of the body mass index BMI), and waist circumference (WC) were performed. Data on dietary intake were collected using a validated semi-quantitative food frequency questionnaire, for the calculate of the DII. This study was approved by the Human Research Ethics Committees of the University Hospital where patients were selected. All participating provided written informed consent . DII scores were analyzed both as a continuous variable and as a dichotomous variable, categorized based on the controls’ median value of the DII (0.86). Continuous variables were analyzed by Student's t-test and categorical variables were analyzed according to association by Pearson's or Fisher's chi-square test. Odds ratios and 95% confidence intervals were estimated using logistic regression models. A p value <0.05 (2 tailed) was considered statistically significant .
Applicable Research laboratory for Developing Countries
Current methods allow for the detection of mycotoxins and mycotoxins metabolites at very low concentrations in food and biological media; however, the application of these methods within developing countries is limited by practical considerations, such as resources and infrastructure. Methods for testing food and biological specimens need to be adapted to fit the surveillance and epidemiologic needs of developing countries. A simple screening method, adapted for developing countries, would benefit subsistence farmers as well as public health and agriculture institutions. Furthermore, these institutions would also benefit from sustainable yet reliable confirmatory methods for use in centralized laboratories.
At field level
Simple and inexpensive field screening methods are available to determine that food is sufficiently free of aflatoxins, but currently lack direct applicability to aflatoxin contamination issues in developing countries. Field methods can be performed with minimal training or equipment and can be performed on site (i.e. at a farm or grain silo). Field methods for aflatoxin analysis allow for rapid confirmation or exclusion of possible exposure at a reasonable cost, thus allowing officials to quickly determine whether further evaluation and intervention is necessary. Such methods would prove beneficial in developing countries given that the remote location of villages and long distances to a centralized laboratory make it impractical to take samples from villages, analyze them in the laboratory, and then travel back to the village to deliver the results.
Improving the cost, durability, ease of transport, and usability of field methods (e.g., simplicity of use, use in the absence of electricity) is necessary to optimize the public health approach to aflatoxin exposure in developing countries. One field method which could be useful involves dipsticks, which are developed to measure up to the cutoff value for aflatoxins in food that corresponds with trade agreements or regulations. However, cutoff values in developed countries are markedly lower than typical food levels in developing countries. Such field tests could prove effective if the cutoff value was adjusted based on chronic exposure, health effects, and action levels necessary for developing countries. Field methods for the analysis of biological samples have not been developed. However, the same concept of using dipsticks can be applied to field tests for biological specimens.
At laboratory level
Laboratory methods, which are more precise yet also more labor intensive and costly, can be used to confirm results of field tests. These methods require instrumentation or techniques not suited to working on site. They require regular maintenance of instrumentation, training of personnel, and a ready supply of reagents and materials. The best laboratory method for testing either food or biological specimen is one that balances the need for quick, accurate results with limitations in resources and infrastructure. Current laboratory methods require further refinement to improve their usability in developing countries. Thin layer chromatography (TLC) is a well suited laboratory method for testing food samples, given its reliability and simplicity; however, it is labor intensive and limited in the number of samples tested in a day.
Early Threatening Methods in Developing Countries
In order to prevent future outbreaks, developing countries need an early warning system which is able to detect potential food contamination events with adverse health effects. Public health surveillance is the ongoing, systematic collection, analysis, interpretation, and dissemination of data regarding a health related event for use in public health action to reduce morbidity and mortality and to improve health. Important characteristics of any surveillance system include simplicity, flexibility, data quality, acceptability, sensitivity, positive predictive value, representativeness, timeliness, and stability. To create an effective and sustainable system, health surveillance and food and biological monitoring strategies must be adapted to meet the needs of developing countries.
Early warning signs need to be validated and a response protocol needs to be developed. Previous outbreaks have been identified by physicians noticing an increase in cases of jaundice despite a lack of any organized or official reporting system. While a national reporting system for jaundice would prove beneficial for developing countries, the baseline rate of jaundice and all its possible causes are not known. In addition, aflatoxicosis confirmation tests using biological markers are limited. An early warning system should also involve monitoring aflatoxin levels in food sources or individuals in order to prevent or reduce the health impact. Monitoring aflatoxin levels in food or individuals to identify those at risk for disease is more difficult than monitoring rates of jaundice. However, food and biological monitoring may identify susceptibility sooner and allow for a more timely intervention. To maximize resources, monitoring or surveillance should target high risk areas or populations and the most appropriate specimen food, urine, or serum, should be collected. A rapid, field test that analyzes aflatoxin adducts in biological samples would be ideal for an early warning system that incorporates bio monitoring. Ultimately an early warning system should rely on multiple sources of information and triggers that would set in motion various responses for preventing or reducing an outbreak of mycotoxins.
Triggers for action could also be based upon other factors which indicate or influence mycotoxins contamination, such as reporting of death among livestock or domestic animals which are often given lower quality grain.
Modeling of mycotoxins infection based on weather conditions from planting to post-harvest could also serve as a trigger. Such modeling would require further validation and an infrastructure for weather monitoring and dissemination of information. But, it may be the easier and less expensive trigger to implement and would also allow for the earliest intervention in preventing further mycotoxins development. An early warning system must also include a response protocol to prevent further aflatoxin exposure and associated health outcomes once a contaminated food source is identified. A protocol can only be effective if the infrastructure and funds to replace contaminated food exist and a method for identifying families in need has been determined. Inclusion of key members from various government agencies, the health care sector, and non-governmental organizations in an effective communication strategy and in all response efforts is necessary to ensure that an early warning system is successful.
Interactions and Co-existence of Multiple Mycotoxins
Food commodities affected by aflatoxins are also susceptible to other types of mycotoxins and multiple mycotoxins can co-exist in the same commodity. Various cereals affected by aflatoxins are also susceptible to contamination by fumonisins, trichothecenes (especially deoxynivalenol), zearalenone, ochratoxin A and ergot alkaloids. Maize can be contaminated with aflatoxins, fumonisin, trichothecenes, zearalenone and, rarely, ochratoxin-A, while wheat can be contaminated by aflatoxins, trichothecenes, ochratoxin-A, ergot alkaloids and zearalenone. Therefore individuals may be exposed to various combinations of mycotoxins. The health effects associated with exposure to multiple mycotoxins are not well documented. Related mycotoxins are thought to have an additive effect while unrelated mycotoxins may have a synergistic effect. A better understanding of exposure to multiple mycotoxins and the health effects associated with the interactions of multiple mycotoxins would clarify the true health impact of mycotoxins.
While a great deal is known about mycotoxins, much is not known about mycotoxins exposure and the resulting health effects in developing countries. Even without a complete understanding of the public health problem initiated by mycotoxins, it is clear that acute mycotoxins are preventable and chronic exposure can be reduced. The four recurrent themes that were evident throughout the workshop and warrant immediate attention are:
• Quantify the human health impacts and the burden of disease due to mycotoxins exposure.
• Compile an inventory, evaluate the efficacy, and disseminate results of on-going intervention strategies.
• Develop and augment the disease surveillance, food monitoring, laboratory, and public health response capacity of affected regions. and
• Develop a response protocol that can be used in the event of an outbreak of acute mycotoxins.
These steps will provide much needed knowledge about the pattern and resulting health effects of aflatoxin exposure and will enable the development of effective, culturally appropriate interventions for reducing chronic levels of exposure. Although mycotoxins exposure is not a new issue, it requires new strategies to address it effectively within developing countries, where mycotoxins exposure is intertwined with the issues of food insecurity and insufficiency. Collaboration between the agricultural and public health communities, between the local, regional, national, and international governing bodies, and between different disciplines within public health and agricultural is essential to reduce mycotoxins exposure.
- Eaton DL, Groopman JD. The Toxicology of aflatoxins: Human health, veterinary, and agricultural significance. San Diego, CA, Academic Press, INC. Elias-Orozco R A. 2014.
- Wild CP, PC Turner PC. The toxicology of aflatoxins as a basis for public health decisions. Mutagenesis 2012; 17(6): 471-481.
- Fung F, Clark RF. Health effects of mycotoxins: A toxicological overview. J Toxicol Clin Toxicol. 2014;42(2): 217-234.
- Williams JH, Phillips TD, Pauline E Jolly, et al. Human aflatoxicosis in developing countries: A review of toxicology, exposure, potential health consequences, and interventions. Am J Clin Nutr. 2014;80(5):1106-1122.
- Guo B, Widstrom N, Lynch RE, et al. Control of preharvest aflatoxin contamination in corn: Fungus-plant-insect interactions and control strategies. Recent Research Developments in Agri and Food Chemi. 2010; 4(1):165-176.
- CDC. Outbreak of aflatoxin poisoning eastern and central provinces, Developing countries, January-July 2014. MMWR Morb Mortal Wkly Rep 2014;53(34):790-793.
- Wilson DM, GA Payne. Factors affecting aspergillusflavus group infection and aflatoxin contamination of the crops.
- Ono EY, Sugiura Y, Hirooka EY, et al. Effect of climatic conditions on natural mycoflora and fumonisins in freshly harvested corn of the State of Parana, Brazil. Mycopathologia. 1999;147(3):139-148.
- Brown RL, Chen ZY, White DG, et al. Resistance to aflatoxin accumulation in kernels of maize inbreds selected for ear rot resistance in West and Central Africa. J Food Prot 2001; 64(3): 396-400.
- Bankole S A, Mabekoje OO. Occurrence of aflatoxins and fumonisins in preharvest maize from south-western Nigeria. Food Addit Contam. 2004;21(3):251-5.
- Fandohan P, Gnonlonfin B, Wingfield MJ, et al. Natural occurrence of fusarium and subsequent fumonisin contamination in preharvest and stored maize in Benin, West Africa. Int J Food Microbiol. 2005;99(2):173-183.
- Hell K, Cardwell KF, Poehling H, et al. The influence of storage practices on aflatoxin contamination in maize in four agroecological zones of Benin, West Africa. J Stored Prod Res. 2000;36(4):365-382.
- Ono E Y, Sasaki EY, Hirooka EY, et al. Post-harvest storage of corn: Effect of beginning moisture content on mycoflora and fumonisin contamination. Food Addit Contam. 2002; 19(11):1081-1090.
- Hawkins LK, Windham GL, Paul W. Effect of different postharvest drying temperatures on Aspergillusflavus survival and aflatoxin content in five maize hybrids. J Food Prot. 2005;68(7):1521-1524.
- Turner PC, Sylla A, Wild CP, et al. Reduction in exposure to carcinogenic aflatoxins by postharvest intervention measures in West Africa: A community-based intervention study. Lancet 2005;365(9475):1950-1956.
- Lye MS, Ghazali AA, Nair RC, et al .An outbreak of acute hepatic encephalopathy due to severe aflatoxicosis in Malaysia. Am J Trop Med Hyg.1995;53(1):68-72.
- Chen SY, Chen CJ, Santella RM, et al. Association of aflatoxin B(1)-albumin adduct levels with hepatitis B surface antigen status among adolescents in Taiwan. Cancer Epidemiol Biomarkers Prev. 2001;10(11):1223-12236.
- Henry SH, Bosch FX, Bowers JC. Aflatoxin, hepatitis and worldwide liver cancer risks. AdvExp Med Biol 2002;504:229-233.
- Omer RE, Kuijsten A, Pieter van 't Veer, et al. Population-attributable risk of dietary aflatoxins and hepatitis B virus infection with respect to hepatocellular carcinoma. Nutr Cancer.2004;48(1): 15-21.
- Qian GS, Ross RK, Groopman JD, et al. A follow-up study of urinary markers of aflatoxin exposure and liver cancer risk in Shanghai, People's Republic of China. Cancer Epidemiol Biomarkers Prev 1994;3(1):3-10.