A Risk Assessment of Aflatoxin M1 Exposure in Low and Mid-Income Dairy Consumers in Kenya

Risk of exposure to aflatoxin M1 through consumption of cow's milk among children in Magadu, Morogoro

Aflatoxin M1 (AFM1) contamination of milk affects the general population with particular attention to children who frequently consume milk as part of complementary food. This study determined AFM1 contamination of cow's milk and estimated the health risk of dietary AFM1 through consumption of cow's milk among children (6 to 36 months) in the Magadu ward of Morogoro region in Tanzania. A total of 165 mother-baby pairs were recruited and interviewed on child feeding practices with a focus on feeding of cow's milk in the past 24 h. Alongside the interview, 100 raw cows' milk samples were collected from subsampled respondent households and were analyzed for AFM1 using enzyme-linked immunosorbent assay (ELISA). The results showed that about 35% of the surveyed children consumed cow's milk in the form of plain milk, incorporated in porridge and/or tea. The amount consumed varied from 62.5 to 500 mls with a median of 125 (125, 250) mls at a frequency of 1 to 2 times a day. All raw cows' milk (100%) samples (n = 100) were found contaminated with AFM1 at concentrations ranging from 0.052 to 9.310 µg/L and median of 2.076 µg/L (1.27, 2.48). All samples were contaminated by AFM1 at levels above the limits of 0.05 µg/L of raw milk set by the Tanzania Bureau of Standard and the European Union, while 97% exceeded 0.5 µg/L set by the US Food and Drug Administration. Exposure to AFM1 due to consumption of cow's milk ranged from 0.0024 to 0.077 µg/kg bw per day with a median of 0.019 (0.0016, 0.026) µg/kg bw per day, while the margin of exposure (MOE) ranged from 5.19 to 166.76 and median 20.68 (15.33, 25.40) implying high risk of public health concern. This study recommends that advocacy on consumption of cows' milk to combat undernutrition in children should consider a holistic approach that considers the milk's safety aspect.

Review, meta-analysis and carcinogenic risk assessment of aflatoxin M1 in different types of milks in Iran

REVIEWS

Despite in recent decades, several studies on the concentration of aflatoxins M1(AFM1) in various milks have been studied, as we know, no systematic review, meta-analysis and carcinogenic risk assessment study was conducted in Iran till now.

OBJECTIVES

In this study, a systematic review was conducted to collect, meta-analysis and carcinogenic risk assessment of the quantitative data regarding the prevalence and concentration of AFM1 in several types of milk produced in Iran.

CONTENT

In our study, the concentration and prevalence of AFM1 in different types of milk (Raw, pasteurized, and UHT) from 113 original articles in Iran using searching the Web of Science, PubMed, Scopus, Science Direct and Google Scholar (in Persian and English) databases from 2002 to august 2021 were collected. The concentration of AFM1 was meta-analyzed using the random effect model (REM) based on type of milk (raw, pasteurized and UHT) subgroups and Monte Carlo simulation (MCS) approach was used to assess safety risks and investigate carcinogenic effects of AFM1 using Crystal-Ball software (Version 11.1.3, Oracle, Inc., USA).

SUMMARY AND OUTLOOK

The 113 original article (In English and Persian) were included in this review. Meta-analysis indicated lower and upper of AFM1 in subgroups of raw, pasteurized and UHT milk in Iran was 9, 720, 2.7, 230.2, 19.23, and 221.6 ng/kg respectively. The Point estimate for carcinogenic risk of AFM1 showed as result of age increasing, the carcinogenic risk of Aflatoxin M 1 decreases and concentration of Aflatoxin M1 (ng/liter), plays the most effective role in carcinogenic risk of AFM1.

CONCLUSION

The presence of AFM1 in milk and its products due to its high toxicity and carcinogenic properties is a public health concern that the results show that the risk of carcinogenesis is higher at younger ages (less than 20 years). As a result, there is a strong association between consumption of raw milk, pasteurized milk and UHT and the risk of cancer in children and adults in Iran.

Second order probabilistic assessment of chronic dietary exposure to aflatoxin M1 in Serbia

Considering the genotoxic and cancerogenic nature of aflatoxin M1 (AFM1), its presence in milk and dairy products may pose health risks for consumers. The chronic exposure was calculated using a two-dimensional (second order) Monte Carlo model. Results of 13 722 milk and dairy product samples analysed in the 2015-2022 period were used. Milk and dairy products intake information was collected with a Food Frequency Questionnaire (FFQ) validated by a 24-h recall-based method. Risk characterization was done by calculation of the Margin of Exposure (MOE) and by calculation of AFM1 induced number of hepatocellular carcinoma (HCC) cases. Mean AFM1 Estimated Daily Intake (EDI) was highest in children at 0.336 (CI: 0.294-0.385) ng kg^-1 bw day^-1, followed by adolescents with 0.183 (CI: 0.164-0.204), then adult females with 0.161 (CI: 0.146-0.179) and finally adult males with lowest EDI of 0.126 (CI: 0.115-0.139) ng kg^-1 bw day^-1. MOE values based on mean EDI for all population groups were above risk associated threshold and the number of possible HCC cases was in the range of 0.0002-0.0021 cases per year for 10⁵ individuals. The results suggest low health risks due to AFM1 exposure for the whole population. Still, this risk is not non-existent, especially for children as they have a higher ratio of the population exposed to risk associated AFM1 levels, with MOE values below risk indicating threshold starting at 77.5th percentile.

Exposure and Health Risk Assessment of Aflatoxin M1 in Raw Milk and Cottage Cheese in Adults in Ethiopia

Aflatoxin M₁ (milk toxin) found in milk is formed from the hepatic biotransformation of AFB₁ (aflatoxin B₁) and poses a risk to human health when consumed. The risk assessment of AFM₁ exposure due to milk consumption is a valuable way to assess health risk. The objective of the present work was to determine an exposure and risk assessment of AFM₁ in raw milk and cheese, and it is the first of its kind in Ethiopia. Determination of AFM₁ was conducted using an enzyme-linked immunosorbent assay (ELISA). The results indicated that AFM₁ was positive in all samples of milk products. The risk assessment was determined using margin of exposure (MOE), estimated daily intake (EDI), hazard index (HI), and cancer risk. The mean EDIs for raw milk and cheese consumers were 0.70 and 0.16 ng/kg bw/day, respectively. Our results showed that almost all mean MOE values were <10,000, which suggests a potential health issue. The mean HI values obtained were 3.50 and 0.79 for raw milk and cheese consumers, respectively, which indicates adverse health effects for large consumers of raw milk. For milk and cheese consumers, the mean cancer risk was 1.29 × 10^-6 and 2.9 × 10^-6 cases/100,000 person/year, respectively, which indicates a low risk for cancer. Therefore, a risk assessment of AFM₁ in children should be investigated further as they consume more milk than adults.

Aflatoxins in Feed: Types, Metabolism, Health Consequences in Swine and Mitigation Strategies

Feeding farm animals with aflatoxin-contaminated feed can cause various severe toxic effects, leading to increased susceptibility to infectious diseases and increased mortality, weight loss, poor performance and reduced reproductive capability. Following ingestion of contaminated foodstuffs, aflatoxins are metabolized and biotransformed differently in animals. Swine metabolism is not effective in detoxifying and excreting aflatoxins, meaning the risk of aflatoxicosis is increased. Thus, it is of great importance to elucidate the metabolism and all metabolic pathways associated with this mycotoxin. The damage induced by AFB1 in cells and tissues consists of inhibition of cell proliferation, carcinogenicity, immunosuppression, mutagenicity, oxidative stress, lipid peroxidation and DNA damage, leading to pathological lesions in the liver, spleen, lymph node, kidney, uterus, heart, and lungs of swine. At present, it is a challenging task and of serious concern to completely remove aflatoxins and their metabolites from feedstuff; thus, the aim of this study was a literature review on the deleterious effects of aflatoxins on swine metabolism, as well as alternatives that contribute to the detoxification or amelioration of aflatoxin-induced effects in farm animal feed.

May phytophenolics alleviate aflatoxins-induced health challenges? A holistic insight on current landscape and future prospects

The future GCC-connected environmental risk factors expedited the progression of nCDs. Indeed, the emergence of AFs is becoming a global food security concern. AFs are lethal carcinogenic mycotoxins, causing damage to the liver, kidney, and gastrointestinal organs. Long-term exposure to AFs leads to liver cancer. Almost a variety of food commodities, crops, spices, herbaceous materials, nuts, and processed foods can be contaminated with AFs. In this regard, the primary sections of this review aim to cover influencing factors in the occurrence of AFs, the role of AFs in progression of nCDs, links between GCC/nCDs and exposure to AFs, frequency of AFs-based academic investigations, and world distribution of AFs. Next, the current trends in the application of PPs to alleviate AFs toxicity are discussed. Nearly, more than 20,000 published records indexed in scientific databases have been screened to find recent trends on AFs and application of PPs in AFs therapy. Accordingly, shifts in world climate, improper infrastructures for production/storage of food commodities, inconsistency of global polices on AFs permissible concentration in food/feed, and lack of the public awareness are accounting for a considerable proportion of AFs damages. AFs exhibited their toxic effects by triggering the progression of inflammation and oxidative/nitrosative stress, in turn, leading to the onset of nCDs. PPs could decrease AFs-associated oxidative stress, genotoxic, mutagenic, and carcinogenic effects by improving cellular antioxidant balance, regulation of signaling pathways, alleviating inflammatory responses, and modification of gene expression profile in a dose/time-reliant fashion. The administration of PPs alone displayed lower biological properties compared to co-treatment of these metabolites with AFs. This issue might highlight the therapeutic application of PPs than their preventative content. Flavonoids such as quercetin and oxidized tea phenolics, curcumin and resveratrol were the most studied anti-AFs PPs. Our literature review clearly disclosed that considering PPs in antioxidant therapies to alleviate complications of AFs requires improvement in their bioavailability, pharmacokinetics, tissue clearance, and off-target mode of action. Due to the emergencies in the elimination of AFs in food/feedstuffs, further large-scale clinical assessment of PPs to decrease the consequences of AFs is highly required.

Farmer’s knowledge and suggested approaches for controlling aflatoxin contamination of raw milk in Pakistan

Monitoring of aflatoxin levels in milk is often complicated in developing countries due to the dominance of informal markets channeling milk in raw form. Farmer’s awareness and voluntary participation in aflatoxin mitigation can be critical in such scenarios. Therefore, the present study was conducted to understand the perceptions of dairy farmers about aflatoxins and link it with aflatoxin mitigation programs on milk in Pakistan. Information was collected from 450 peri-urban dairy farmers in seven cities using questionnaires. Majority (77.9%) of the farmers were aware of the negative impact of moldy feed on animal health. However, only 40.6% of the farmers were aware of the transferability of the toxins from moldy feed to milk. The farmers had almost no awareness of aflatoxins as 95% never heard of the term. After receiving an onsite briefing on effects of the toxin on animal and human health, and its transferability to milk, 98.3% farmers showed willingness to buy aflatoxin-safe feedstuffs, while 88.5% showed willingness to control aflatoxin in milk. Around half of the farmers considered aflatoxin control programs as affordable. On average, farmers agreed to pay 10.1% higher price for aflatoxin certified oilseed cakes. Availability of feedstuffs certified of low aflatoxin content was suggested by 22% of the participants as the critical step in reducing aflatoxins in milk. Other important suggestions included; subsidy on quality feeds (18%), raising awareness (18%), and legislation and monitoring (16%). The present results suggest that the current practice of milk monitoring in the country can yield desirable results only if it is coupled with feed certification programs ensuing availability of aflatoxin-safe feeds. Further, awareness can positively impact participation of producers in aflatoxin control programs. In this regard, awareness about effects of aflatoxins on animal health was found to be a more powerful trigger of voluntary control compared with the awareness of the toxin’s transferability to milk.

Aflatoxin M1 exposure in a fermented millet-based milk beverage 'brukina' and its cancer risk characterization in Greater Accra, Ghana

Brukina is a millet based fermented milk product which is consumed as a beverage in Ghana. It is however prone to aflatoxin M1 (AFM1) contamination, which is a serious health challenge for low and middle-income countries in subtropical regions. This study aimed at evaluating AFM1 levels and cancer risks associated with brukina (n = 150) sampled from different locations of the Greater Accra Region of Ghana. AFM1 were measured with High-Performance Liquid Chromatography (HPLC) connected to a Fluorescence Detector (FLD).Cancer risk assessments were also conducted using models prescribed by the Joint FAO/WHO Expert Committee on Additives (JECFA). Out of the 150 samples analyzed for AFM1, 80/150 (53%) tested positive between the range 0.00 ± 0.001-3.14 ± 0.77 µg/kg. Cancer risk assessments of AFM1 produced outcomes which ranged between 0.64 and 1.88 ng/kg bw/day, 0.31-9.40, 0.0323, and 1.94 × 10-3-0.06 for cases/100,000 person/yr for Estimated Daily Intake (EDI), Hazard Index (H.I), Average Potency, and Cancer Risks respectively for all age categories investigated. It was concluded that the consumption of brukina posed adverse health effects on the majority of the age categories in the different locations of Greater Accra Region since the calculated H.Is were greater than one (> 1). Therefore, contamination of brukina with AFM1 should be considered a high priority in public health and Ghana's cancer risk management actions.

Aflatoxin M1 Contamination of Ghanaian Traditional Soft Cottage Cheese (Wagashie) and Health Risks Associated with Its Consumption

Wagashie is an unripened traditional cheese consumed in West Africa including Ghana. Being a milk product, it is unfortunately susceptible to aflatoxin M1 (AFM1) contamination, which is indeed a grave health challenge globally. This study evaluated AFM1 levels and health risk characterization associated with wagashie (n = 182) sampled from different locations in Ghana. AFM1 was measured with high-performance liquid chromatography with a fluorescence detector (HPLC-FLD). Risk assessments were also conducted using models prescribed by the Joint FAO/WHO Expert Committee on Food Additives (JECFA). Out of the 182 samples analyzed for AFM1, 93/182 (51.1%) tested positive between the range 0.00 ± 0.00–3.60 ± 0.99 µg/kg. Risk assessments of AFM1 using deterministic models produced outcomes that ranged between 0.11 and 3.60 ng/kg bw/day, 0.09–1.54, 0–0.0323 ng aflatoxins/kg bw/day, and 3.5 x 10−3 −0.06 cases/100,000 person/yr for estimated daily intake (EDI), margin of exposure (MOE), average potency, and cancer risks, respectively, for the age categories investigated. It was established that the consumption of wagashie posed adverse health effects on all age categories in the selected regions of the study because all calculated MOE values were less than 100,000. Therefore, contamination of wagashie with AFM1 should be a serious public health concern and as such considered a high precedence for Ghana’s risk management actions.

Kenya's informal milk markets and the regulation-reality gap

MOTIVATION

Around 80% of milk in Kenya is marketed informally, providing livelihoods and contributing to the food security and nutrition of low-income consumers. Government policy, however, is focused on formalization-primarily through licensing and pasteurization-with enforcement via fines, confiscation of milk, or closing the premises of informal actors.

PURPOSE

This article seeks to better understand if, and why, Kenya's informal milk sector and regulatory system are disconnected from one another and how the policy-reality gap might be better bridged.

METHODS AND APPROACH

To understand the nature and performance of Kenya's informal milk markets and their governance, we used a mix of research methods and data sources, including surveys with informal market players, and key informant interviews with key sector stakeholders. Fieldwork was carried out in Nairobi in late 2018.

FINDINGS

Milk safety and quality matters to all actors in informal milk value chains. The trust-based system used is effective in moderating behaviours and assessing and prioritizing quality and safety. Government policy is not accomplishing the stated goal of formalization: licensing levels remain low among informal actors. Pasteurization is not rewarded in the market. There is some evidence of suboptimal pasteurization processes being undertaken to satisfy regulators. There is a gap between the reality of Kenya's informal milk sector and its regulatory system.

POLICY IMPLICATIONS

The regulation-reality gap manifests itself as adversarial relationships between regulators and informal actors, and unnecessary transaction costs, missing opportunities for enhancing livelihoods, food safety, and food security. New approaches should build on and consider existing approaches taken by actors in informal food markets to ensure food safety and quality. Policy-makers should seek to communicate more effectively with informal actors and engage in more constructive dialogue on inclusive ways forward.

Aflatoxin M1 in Raw Milk, Pasteurized Milk and Cottage Cheese Collected along Value Chain Actors from Three Regions of Ethiopia

Milk is a highly nutritious and perfect natural food for humans. However, when lactating animals feed on Aflatoxin B1 (AFB1)-containing feed, the hydroxyl metabolite aflatoxin M1 (AFM1) contaminates the milk and dairy products. The objective of the current study was to assess the level of AFM1 in raw milk, normally pasteurized milk and Ethiopian cottage cheese collected from value chain actors (producers, collectors, processors and retailers). Cross-sectional study and simple random techniques were used to collect primary samples. A total of 160 composite samples was collected; raw milk (n = 64), pasteurized milk (n = 64) and cheese (n = 32) was analyzed. Quantitative analysis of AFM1 was conducted using enzyme-linked immunosorbent assay (ELISA). The results indicate that AFM1 was detected in all milk products. Results along value chains show that the concentration of AFM1 in raw milk from collectors was significantly higher than from producers, and in pasteurized milk from processors and retailers (p < 0.05). However, no significant (p > 0.05) difference was observed in cottage cheese value-chain actors in all regions. Comparison of AFM1 mean values among all dairy products shows that raw milk had a significantly higher concentration of AFM1 followed by pasteurized milk and cottage cheese. However, there was no significant difference between raw and pasteurized milk (p > 0.05). The mean AFM1 contamination in milk products ranged from 0.137 to 0.319 µg/L (mean value 0.285 µg/L). The contamination percentages of AFM1 in raw milk (62.50%), pasteurized milk (67.20%) and cottage cheese (25%) were above the regulatory limit set by the European Union (EU) (0.05 µg/L). According to USA/Ethiopian Standard (US/ES) (0.50 µg/L), 21.87%, 25% and 1% exceeded the regulatory limit for the above products, respectively. The overall prevalence (56.88%) was above the EU regulatory limit and 19.38% over US/ES regulations. Therefore, to provide accurate information about the health risk to consumers, there is a need to conduct risk assessment studies in consumers of milk and dairy products at different age groups.

AFM1 Secretion and Efficacy of NovasilTM Clay in Kenyan Dairy Cows

The occurrence of aflatoxin M1 (AFM1) in milk has been widely reported in Kenya, with levels freqently exceeding national and international thresholds. Exposure to aflatoxin increases the risk of hepatic cancers and can also have other negative health impacts in children such as growth impairment and immunosuppression. Anti-mycotoxin agents (AMAs) included in contaminated feeds can greatly reduce the amount of AFM1 released in milk. A 45-day trial was designed to assess secretion of AFM1 in milk from individual cows fed commercial Kenyan dairy feed, as well as the efficacy of Novasil™ Plus in reducing the levels. A four-by-four Latin square cross-over design was used for the experiment. Four cows were fed on naturally contaminated with AFB1 feed, with levels ranging from 19 to 47 µg/kg, and either no binder or inclusion of binder at the rate of 0.6 or 1.2%. Milk samples were collected each day and analyzed for AFM1. The results showed that AFM1 levels in the milk varied between the cows, even when fed similar levels of contaminated feed. On average, inclusion of 0.6% binder into the diet resulted in 34% decline in milk AFM1 levels, while 1.2% binder dose resulted in a decline of 45%. Significant reduction in AFM1 secretion was observed in all experimental units (p < 0.005), though only minimal reduction was recorded in one of the units (Cow 4) compared to the other three. This trial shows novel data on aflatoxin exposure and excretion in Kenyan dairy cows in a field setting where AFB1 level is uncontrolled. We demonstrate significant reduction in AFM1 secretion in milk using AMA, though AFM1 levels were still above the recommended EC standard of 50 ŋg/kg. This study suggests that AMAs alone cannot be relied on to reduce AFM1 in milk to safe levels. Training and good feeding practices are recommended in addition to use of AMAs.

Preliminary sampling of aflatoxin M1 contamination in raw milk from dairy farms using feed ingredients from Rwanda

Milk is susceptible to aflatoxin M1 (AFM₁) contamination when dairy cattle consume feed contaminated with aflatoxins and is considered as a public health concern. This pilot study assessed the prevalence and amount of total aflatoxin contamination in commercially available dairy feed and the corresponding AFM₁ contamination in raw milk from samples collected at farms using local, commercially available dairy feed across Rwanda's five provinces. The inclusion criteria to select dairy farm participants were (1) to have at least two cows and (2) use of commercially prepared dairy feeds. Importantly, the majority of cattle rearing households in Rwanda rely principally on grazing or other freely available feedstock, rather than on commercially prepared feeds. In total, 170 raw milk samples were collected during one sampling period from dairy farms using commercially prepared dairy feeds. In addition, 154 dairy feed samples were collected simultaneously with the milk samples. These farms were previously targeted in a larger study measuring aflatoxin contamination of Rwandan feeds and feed ingredients. The mean AFM₁ concentration in these samples was 0.89 ± 1.64 µg/l (median: 0.33 µg/l) with a maximum of 14.5 µg/l. Maize bran was the principal dairy feed ingredient used by farmers in the sampling, representing more than 65% of the total feed samples collected, with mean aflatoxin concentration of 90.5 µg/kg (median 32.3 µg/kg). The authors note that this preliminary sampling is not generalizable across Rwandan milk production and consumption; the limited pilot study presented here was not designed with the robustness necessary for broad-scale generalization. Thus, the data presented should not be broadly applied outside of the context of the study.

Innovative application of postbiotics, parabiotics and encapsulated Lactobacillus plantarum RM1 and Lactobacillus paracasei KC39 for detoxification of aflatoxin M1 in milk powder

This study aimed to evaluate aflatoxin M1 (AFM1) level in milk powder and infant milk formulae, in addition to applying innovative methods for AFM1 & AFB1 detoxification. Fifty random samples of milk powder and infant formulae (25 of each) were collected from the Egyptian markets for assessing AFM1 level using ELISA technique. Bioactive components comprising cell free supernatants (postbiotic), acid-dead cells (parabiotic) and the encapsulated-cells of Lactobacillus plantarum RM1 and Lactobacillus paracasei KC39 were evaluated for their antifungal activity against toxigenic mold strains and their impact on AFB1 and AFM1 reduction in reconstituted milk powder. AFM1 concentration in unpacked milk powder was higher than that of packed samples and infant formulae, although these differences were not significant (P > 0.05). About 96.0, 29.4 and 25.0% of the tested infant formulae, unpacked, and packed milk powder were unacceptable in terms of the AFM1 limit defined by Egyptian and European standards, while all samples were in accordance with the USA/FDA standard. All tested mycotoxigenic strains were sensitive to the different treatments of the probiotics with the highest sensitivity regarding Fusarium strain with L. paracasei KC39 compared to other genera. The degradation ratios of AFM1 using the bioactives of the L. paracasei KC39 were higher than that of L. plantarum RM1 bioactives. Additionally, KC39 parabiotic manifested the best AFB1 reduction (60.56%). In conclusion, the positive and highly significant relationship (P < 0.05) between these effective biocompounds mirrors their major detoxification role which gives a safe solution for AFs contamination issues in milk and milk products.

Presence of Aflatoxin M1 in Commercial Milk in Paraguay

ABSTRACT

The presence of aflatoxin M1 (AFM1) in milk is a public health concern because milk is a significant part of human diets worldwide. In economies where AFM1 monitoring is low or nonexistent, the possibility of AFM1 contamination might be increased. Our study was conducted to detect and quantify AFM1 in fluid milk and milk drinks of various brands, fat concentrations, packages, and heat treatments sold in the Metropolitan Area of Asunción, Paraguay. Eighty samples were collected from supermarkets in the Metropolitan Area of Asunción following a nonprobability sampling method. An enzyme-linked immunosorbent assay for AFM1 (25 to 500 ppt) was used to quantify the toxin, and results were analyzed with nonparametric methods. All samples were positive values for AFM1 (above the detection limit of 25 ng/kg); 85% of the samples had 30 to 50 ng/kg, and 15% had >500 ng/kg. No significant difference in AFM1 concentration was found based on fat concentration, heat treatment, or type of packaging of these milk products; however, significant differences were found between brands.

HIGHLIGHTS

Management strategies for aflatoxin risk mitigation in maize, dairy feeds and milk value chains—case study Kenya

Widespread aflatoxin contamination of a great number of food and feed crops has important implications on global trade and health. Frequent occurrence of aflatoxin in maize and milk poses serious health risks to consumers because these commodities are staple foods in many African countries. This situation calls for development and implementation of rigorous aflatoxin control measures that encompass all value chains, focusing on farms where food and feed-based commodities prone to aflatoxin contamination are cultivated. Good agricultural practices (GAP) have proven to be an effective technology in mitigation and management of the aflatoxin risk under farm conditions. The prevailing global climate change is shown to increase aflatoxin risk in tropical and subtropical regions. Thus, there is an urgent need to devise and apply novel methods to complement GAP and mitigate aflatoxin contamination in the feed, maize and milk value chains. Also, creation of awareness on aflatoxin management through training of farmers and other stakeholders and enforcement of regular surveillance of aflatoxin in food and feed chains are recommended strategies. This literature review addresses the current situation of aflatoxin occurrence in maize, dairy feeds and milk produced and traded in Kenya and current technologies applied to aflatoxin management at the farm level. Finally, a case study in Kenya on successful application of GAP for mitigation of aflatoxin risk at small-scale farms will be reviewed.

Estimating the health burden of aflatoxin attributable stunting among children in low income countries of Africa

Numerous population-based studies have documented high prevalence of aflatoxin associated childhood stunting in low income countries. We provide an estimate of the disease burden of aflatoxin related stunting using data from the four African countries. For this empirical analysis, we obtained blood aflatoxin albumin adduct biomarker based exposure data as measured using ELISA technique and anthropometric measurement data from surveys done over a 12-year period from 2001 to 2012 in four low income countries in Africa. We used these data to calculate population attributable risk (PAR), life time disease burden for children under five by comparing two groups of stunted children using both prevalence and incidence-based approaches. We combined prevalence estimates with a disability weight, measuring childhood stunting and co-occurrence of stunting-underweight to produce years lived with disability. Using a previously reported mortality, years of life lost were estimated. We used probabilistic analysis to model these associations to estimate the disability-adjusted life-years (DALYs), and compared these with those given by the Institute for Health Metrics and Evaluation’s Global Burden of Disease (GBD) 2016 study. The PAR increased from 3 to 36% for aflatoxin-related stunting and 14–50% for co-occurrence of stunting and underweight. Using prevalence-based approach, children with aflatoxin related stunting resulted in 48,965.20 (95% uncertainty interval (UI): 45,868.75–52,207.53) DALYs per 100,000 individuals. Children with co-occurrence of stunting and underweight due to exposure to aflatoxin resulted in 40,703.41 (95% UI: 38,041.57–43,517.89) DALYs per 100,000 individuals. Uncertainty analysis revealed that reducing aflatoxin exposure in high exposure areas upto non-detectable levels could save the stunting DALYs up to 50%. The burden of childhood all causes stunting is greater in countries with higher aflatoxin exposure such as Benin. In high exposure areas, these results might help guide research protocols and prioritisation efforts and focus aflatoxin exposure reduction. HEFCE Global Challenge Research Fund Aflatoxin project.

MILK Symposium review: Foodborne diseases from milk and milk products in developing countries-Review of causes and health and economic implications

Dairy production is rapidly increasing in developing countries and making significant contributions to health, nutrition, environments, and livelihoods, with the potential for still greater contributions. However, dairy products can also contribute to human disease in many ways, with dairyborne disease likely being the most important. Health risks may be from biological, chemical, physical, or allergenic hazards present in milk and other dairy products. Lacking rigorous evidence on the full burden of foodborne and dairyborne disease in developing countries, we compiled information from different sources to improve our estimates. The most credible evidence on dairyborne disease comes from the World Health Organization initiative on the Global Burden of Foodborne Disease. This suggests that dairy products may has been responsible for 20 disability-adjusted life years per 100,000 people in 2010. This corresponds to around 4% of the global foodborne disease burden and 12% of the animal source food disease burden. Most of this burden falls on low- and middle-income countries (LMIC). However, the estimate is conservative. Weaker evidence from historical burden in high-income countries, outbreak reports from LMIC and high-income countries, and quantitative microbial risk assessment suggest that the real burden may be higher. The economic burden in terms of lost human capital is at least US$4 billion/yr in LMIC. Among the most important hazards are Mycobacterium bovis, Campylobacter spp., and non-typhoidal Salmonella enterica. The known burden of chemical hazards is lower but also more uncertain. Important chemical hazards are mycotoxins, dioxins, and heavy metals. Some interventions have been shown to have unintended and unwanted consequences, so formative research and rigorous evaluation should accompany interventions. For example, there are many documented cases in which women's control over livestock is diminished with increasing commercialization. Dairy co-operatives have had mixed success, often incurring governance and institutional challenges. More recently, there has been interest in working with the informal sector. New technologies offer new opportunities for sustainable dairy development.

Aflatoxin M1 in Africa: Exposure Assessment, Regulations, and Prevention Strategies - A Review

Aflatoxins are the most harmful mycotoxins causing health problems to human and animal. Many acute aflatoxin outbreaks have been reported in Africa, especially in Kenya and Tanzania. When ingested, aflatoxin B1 is converted by hydroxylation in the liver into aflatoxin M1, which is excreted in milk of dairy females and in urine of exposed populations. This review aims to highlight the AFM1 studies carried out in African regions (North Africa, East Africa, West Africa, Central Africa, and Southern Africa), particularly AFM1 occurrence in milk and dairy products, and in human biological fluids (breast milk, serum, and urine) of the populations exposed. Strategies for AFM1 detoxification will be considered, as well as AFM1 regulations as compared to the legislation adopted worldwide and the assessment of AFM1 exposure of some African populations. Egypt, Kenya, and Nigeria have the highest number of investigations on AFM1 in the continent. Indeed, some reports showed that 100% of the samples analyzed exceeded the EU regulations (50 ng/kg), especially in Zimbabwe, Nigeria, Sudan, and Egypt. Furthermore, AFM1 levels up to 8,000, 6,999, 6,900, and 2040 ng/kg have been reported in milk from Egypt, Kenya, Sudan, and Nigeria, respectively. Data on AFM1 occurrence in human biological fluids have also shown that exposure of African populations is mainly due to milk intake and breastfeeding, with 85-100% of children being exposed to high levels. Food fermentation in Africa has been tried for AFM1 detoxification strategies. Few African countries have set regulations for AFM1 in milk and derivatives, generally similar to those of the Codex alimentarius, the US or the EU standards.

Aflatoxin M1 in raw cow milk and associated hepatocellular carcinoma risk among dairy farming households in Malawi

In the present study, a total of 112 raw milk samples were collected between October and December of 2018 from dairy farming households in Malawi and analyzed for aflatoxin M1 (AFM1) using VICAM aflatest fluorometry procedure. These data together with the consumption data obtained through a milk consumption frequency questionnaire were used for the calculation of AFM₁ exposure and its association with hepatocarcinoma (HCC) risk in dairy farming population. Average daily milk intake by children and adults were approximately 300 ± 0.07 and 541.7 ± 0.14 mL, respectively. All raw milk samples tested positive to AFM₁ averaging 0.551 μg/L. Probable mean daily exposure to AFM₁ for adults was 4.98 ± 7.25 ng/kg BW/day almost half that of children (8.28 ± 11.82 ng/kg BW/day). Estimated risk of AFM₁-induced HCC associated with consumption of milk among children and adults were 0.038 and 0.023 cases per 100,000 individuals per year, respectively. Although the results of this investigation suggest a low risk of HCC, other negative health effects of AFM₁ justify its continuous monitoring and update of the risk assessment. This work presents the first insight in the occurrence of AFM₁ in cow milk in Malawi as well as associated AFM₁ exposure in dairy farming population.

Biomedical applications of dendritic fibrous nanosilica (DFNS): recent progress and challenges

Dendritic fibrous nanosilica (DFNS), with multi-component and hierarchically complex structures, has recently been receiving significant attention in various fields of nano-biomedicine. DFNS is an emerging class of mesoporous nanoparticles that has attracted great interest due to unique structures such as open three-dimensional dendritic superstructures with large pore channels and highly accessible internal surface areas. This overview aims to study the application of DFNS towards biomedical investigations. This review is divided into four main sections. Sections 1–3 are related to the synthesis and characterization of DFNS. The biomedical potential of DFNS, such as cell therapy, gene therapy, immune therapy, drug delivery, imaging, photothermal therapy, bioanalysis, biocatalysis, and tissue engineering, is discussed based on advantages and limitations. Finally, the perspectives and challenges in terms of controlled synthesis and potential nano-biomedical applications towards future studies are discussed.

Dendritic fibrous nanosilica (DFNS) , with multi-component and hierarchically complex structures, has recently been receiving significant attention in various fields of nano-biomedicine.

Aflatoxin M1 in Nicaraguan and locally made hard white cheeses marketed in El Salvador

•

Cheeses marketed in El Salvador have high prevalence of Aflatoxin M₁ contamination.

•

Cheese contamination by Aflatoxin M₁ is endemic in both El Salvador and Nicaragua.

•

Aflatoxin M₁ contamination in cheeses is higher during dry season.

Aflatoxin M₁ is a carcinogenic and genotoxic metabolite of Aflatoxins present in food contaminated by fungi for lactating cattle, it is excreted through milk and when used to make cheese, the toxin will also be transferred to the dairy. The contamination of unripened hard white cheese with AFM₁ seems to vary according to the season of the year, possibly due to the change of foodstuff, from fresh pasture in the rainy season to dried foods in the dry season and vice versa. This research determined both the prevalence and contents of AFM₁ in cheeses of local and Nicaraguan origin marketed in El Salvador, as well as the changes occurred according to the season and the association between levels of AFM₁ with meteorological parameters. The significantly higher prevalence of AFM₁ contamination in both local cheeses and Nicaraguans, was found in the dry season and the lowest in the rainy season (41 % vs. 20 %; 31 % vs. 0%, respectively), the same trend was observed in AFM₁ contents (0.076 vs. 0.036 μg/kg; 0.050 vs. 0.021 μg/kg, respectively). A significant association was demonstrated between levels of AFM₁ with the averages of accumulated rainfall and relative humidity according to the sampled season. The prevalence of AFM₁ in cheeses indicate that El Salvador and Nicaragua are endemic to dairy contamination by that mycotoxin. Seasonal variation may be due to a lack of rainfall, that promotes the growth of aflatoxigenic fungi in the crops of raw materials, which will be used for feedstuff intended for dairy cattle, thus, the consumption of contaminated food will cause the temporary increase of AFM₁ in milk and their derivatives.

A Review of the Impact of Mycotoxins on Dairy Cattle Health: Challenges for Food Safety and Dairy Production in Sub-Saharan Africa

Mycotoxins are secondary metabolites of fungi that contaminate food and feed and have a significant negative impact on human and animal health and productivity. The tropical condition in Sub-Saharan Africa (SSA) together with poor storage of feed promotes fungal growth and subsequent mycotoxin production. Aflatoxins (AF) produced by Aspergillus species, fumonisins (FUM), zearalenone (ZEN), T-2 toxin (T-2), and deoxynivalenol (DON) produced by Fusarium species, and ochratoxin A (OTA) produced by Penicillium and Aspergillus species are well-known mycotoxins of agricultural importance. Consumption of feed contaminated with these toxins may cause mycotoxicoses in animals, characterized by a range of clinical signs depending on the toxin, and losses in the animal industry. In SSA, contamination of dairy feed with mycotoxins has been frequently reported, which poses a serious constraint to animal health and productivity, and is also a hazard to human health since some mycotoxins and their metabolites are excreted in milk, especially aflatoxin M1. This review describes the major mycotoxins, their occurrence, and impact in dairy cattle diets in SSA highlighting the problems related to animal health, productivity, and food safety and the up-to-date post-harvest mitigation strategies for the prevention and reduction of contamination of dairy feed.

Aflatoxin M1 binding by lactic acid bacteria in milk

This research focused on biocontrol solution to increase food safety through studying lactic acid bacteria (LAB) which can bind aflatoxins in milk. Aflatoxins are toxic contaminants found in feeds and foods. In milk aflatoxin is found in metabolised form, aflatoxin M1 (AFM1). Three indigenous LAB Lactobacillus strains and one Lactococcus strain isolated from Kenyan spontaneously fermented foods were tested for their AFM1 binding abilities in different conditions and after different treatments along with two reference Lactobacillus strains. Binding of AFM1 in different concentrations was examined with unconcentrated, concentrated, heat treated and concentrated heat-treated LAB cultures. Observed binding of AFM1 by LAB varied between 11 to 100%, being approximately at the level of 40% throughout the analysis sets. The results of this study suggest that the aflatoxin binding ability by LAB strain is not strongly strain specific and depends on many external and condition variables. Also, the methods used in determination of aflatoxin binding warrant critical evaluation.

Aflatoxin Exposure from Milk in Rural Kenya and the Contribution to the Risk of Liver Cancer

Milk is an important commodity in Kenya; the country has the largest dairy herd and highest per capita milk consumption in East Africa. As such, hazards in milk are of concern. Aflatoxin M₁ (AFM₁) is a toxic metabolite of aflatoxin B₁ (AFB₁) excreted in milk by lactating animals after ingesting AFB₁-contaminated feeds. This metabolite is injurious to human health, but there is little information on the risk to human health posed by AFM₁ in milk in rural Kenya. To fill this gap, a quantitative risk assessment (QRA) applying probabilistic statistical tools to quantify risks was conducted. This assessed the risk of liver cancer posed by AFM₁ in milk, assuming 10-fold lower carcinogenicity than AFB₁. Data from four agro–ecological zones in Kenya (semi-arid, temperate, sub-humid and humid) were used. We estimated that people were exposed to between 0.3 and 1 ng AFM₁ per kg body weight per day through the consumption of milk. The annual incidence rates of cancer attributed to the consumption of AFM₁ in milk were 3.5 × 10⁻³ (95% CI: 3 × 10⁻³–3.9 × 10⁻³), 2.9 × 10⁻³ (95% CI: 2.5 × 10⁻³–3.3 × 10⁻³), 1.4 × 10⁻³ (95% CI: 1.2 × 10⁻³–1.5 × 10⁻³) and 2.7 × 10⁻³ (95% CI: 2.3 × 10⁻³–3 × 10⁻³) cancers per 100,000 in adult females, adult males, children 6–18 years old, and in children less than five years old, respectively. Our results show that aflatoxin exposure from milk contributes relatively little to the incidence of liver cancer. Nonetheless, risk managers should take action based on cumulative exposure from all sources of aflatoxins.

Aflatoxin Binders in Foods for Human Consumption-Can This be Promoted Safely and Ethically?

Aflatoxins continue to be a food safety problem globally, especially in developing regions. A significant amount of effort and resources have been invested in an attempt to control aflatoxins. However, these efforts have not substantially decreased the prevalence nor the dietary exposure to aflatoxins in developing countries. One approach to aflatoxin control is the use of binding agents in foods, and lactic acid bacteria (LAB) have been studied extensively for this purpose. However, when assessing the results comprehensively and reviewing the practicality and ethics of use, risks are evident, and concerns arise. In conclusion, our review suggests that there are too many issues with using LAB for aflatoxin binding for it to be safely promoted. Arguably, using binders in human food might even worsen food safety in the longer term.

Occurrence of aflatoxin M1 in raw milk traded in peri-urban Nairobi, and the effect of boiling and fermentation

Background: Dairy production in Kenya is important and dominated by small-holder farmers who market their produce through small-scale traders in the informal sector. Method: This study aimed to determine the prevalence of aflatoxin (AFM1) in informally marketed milk in peri-urban Nairobi, Kenya, and to assess knowledge of milk traders on aflatoxins using questionnaires. A total of 96 samples were analyzed for AFM1 using enzyme-linked immunosorbent assay. In addition, boiling and fermentation experiments were carried out in the laboratory. Results: All samples had AFM1 above the limit of detection (5 ng/kg) (mean of 290.3 ± 663.4 ng/kg). Two-thirds of the samples had AFM1 levels above 50 ng/kg and 7.5% of the samples exceeded 500 ng/kg. Most of the traders had low (69.8%) or medium (30.2%) knowledge. Educated (p = 0.01) and female traders (p= 0.04) were more knowledgeable. Experimentally, fermenting milk to lala (a traditional fermented drink) and yogurt significantly reduced AFM1 levels (p< 0.01) (71.8% reduction in lala after incubation at room temperature for 15 h, and 73.6% reduction in yogurt after incubation at 45ºC for 4h). Boiling had no effect. Conclusion: The study concluded that the prevalence of raw milk with AFM1 was high, while knowledge was low. Fermentation reduced the AFM1 levels.

Mycotoxins at the Start of the Food Chain in Costa Rica: Analysis of Six Fusarium Toxins and Ochratoxin A between 2013 and 2017 in Animal Feed and Aflatoxin M1 in Dairy Products

Mycotoxins are secondary metabolites, produced by fungi of genera Aspergillus, Penicillium and Fusarium (among others), which produce adverse health effects on humans and animals (carcinogenic, teratogenic and immunosuppressive). In addition, mycotoxins negatively affect the productive parameters of livestock (e.g., weight, food consumption, and food conversion). Epidemiological studies are considered necessary to assist stakeholders with the process of decision-making regarding the control of mycotoxins in processing environments. This study addressed the prevalence in feed ingredients and compound feed of eight different types of toxins, including metabolites produced by Fusarium spp. (Deoxynivalenol/3-acetyldeoxynivalenol, T-2/HT-2 toxins, zearalenone and fumonisins) and two additional toxins (i.e., ochratoxin A (OTA) and aflatoxin M1 (AFM1)) from different fungal species, for over a period of five years. On the subject of Fusarium toxins, higher prevalences were observed for fumonisins (n = 80/113, 70.8%) and DON (n = 212/363, 58.4%), whereas, for OTA, a prevalence of 40.56% was found (n = 146/360). In the case of raw material, mycotoxin contamination exceeding recommended values were observed in cornmeal for HT-2 toxin (n = 3/24, 12.5%), T-2 toxin (n = 3/61, 4.9%), and ZEA (n = 2/45, 4.4%). In contrast, many compound feed samples exceeded recommended values; in dairy cattle feed toxins such as DON (n = 5/147, 3.4%), ZEA (n = 6/150, 4.0%), T-2 toxin (n = 10/171, 5.9%), and HT-2 toxin (n = 13/132, 9.8%) were observed in high amounts. OTA was the most common compound accompanying Fusarium toxins (i.e., 16.67% of co-occurrence with ZEA). This study also provided epidemiological data for AFM1 in liquid milk. The outcomes unveiled a high prevalence of contamination (i.e., 29.6-71.1%) and several samples exceeding the regulatory threshold. Statistical analysis exposed no significant climate effect connected to the prevalence of diverse types of mycotoxins.

Exposure Assessment and Risk Characterization of Aflatoxin M1 Intake through Consumption of Milk and Yoghurt by Student Population in Serbia and Greece

The objective of this research was to perform an exposure assessment of aflatoxin M1 (AFM1) intake through the consumption of milk and yoghurt by the student population in Serbia and Greece. A food consumption survey of milk and yoghurt was performed during the first half of 2018 in the two countries with at least 500 interviewees (aged between 18 and 27 years) per country, covering their dietary habits and body weight based on one-day and seven-day recall methods. Values for the concentration of AFM1 were extracted from published research. Finally, a Monte Carlo analysis of 100,000 iterations was performed to estimate the intake of AFM1 from the consumption of the two dairy products. Results revealed that the estimated average exposure of students to AFM1 was in the range of 1.238⁻2.674 ng kg^-1 bw day^-1 for Serbia, and 0.350⁻0.499 ng kg^-1 bw day^-1 for Greece, depending on the dietary recall method employed. High estimations for hepatocellular carcinoma (HCC) cases/year/10⁵ individuals, depending on the prevalence of Hepatitis B virus surface antigen positive individuals (HBsAg+), were 0.0036⁻0.0047 and 0.0007⁻0.0009 for Serbia and Greece, respectively. Presented Margin of Exposure (MOE) and Hazard Index (HI) values indicate increased risk from exposure to AFM1, particularly in Serbia.

Status of aflatoxin contamination in cow milk produced in smallholder dairy farms in urban and peri-urban areas of Nairobi County: a case study of Kasarani sub county, Kenya

Introduction: Milk consumption in Kenya supersedes other countries in East Africa. However, milk contamination with aflatoxin M1 (AFM1) is common, but the magnitude of this exposure and the health risks are poorly understood and need to be monitored routinely. This study aimed at assessing the awareness, knowledge and practices of urban and peri-urban farmers about aflatoxins and determining the levels of aflatoxin contamination in on-farm milk in a selected area within Nairobi County. Materials and methods: A cross-sectional study was undertaken to assess aflatoxin contamination levels of milk in Kasarani sub-county. A total of 84 milk samples were collected from small-holder dairy farms and analyzed for AFM1 using Enzyme-Linked Immunosorbent Assay (ELISA). Results and Discussion: Ninety nine percent of the samples (83/84) analysed were contaminated with AFM1. The mean aflatoxin level was 84 ng/kg with 64% of the samples exceeding the EU legal limit of 50 ng/kg. Whereas 80% of the farmers were aware of aflatoxin, there was no correlation between farmers' knowledge and gender with AFM1 prevalence. Conclusion: This study concludes that AFM1 is a frequent contaminant in milk and there is need to enhance farmers awareness on mitigation.