**1. Introduction**

#### **1.1. Aflatoxins and their impact on sub-Saharan Africa**

Most parts of sub-Saharan Africa fall within the region of high perennial risk to mycotoxin contamination. This region is within 40o N and 40o S of the equator with warm and humid environmental conditions [1]. Under these favorable conditions of humidity and temperature,

fungal prevalence is rife. Unfortunately, some fungi, as part of their metabolic processes, synthesize mycotoxins (fungal toxins), that contaminate crops intended for human and animal consumption [2]. Ingestion of contaminated crops results in morbidity and mortality where tolerable levels are exceeded in food and feed [3, 4]. Associated health dysfunctions caused by aflatoxin ingestion include liver carcinoma and other hepatic dysfunctions, stunting in children and associated cognitive deficiencies, reduced immunity, and ailments associated with nutrient malabsorption due to disruption to villi architecture [5–7]. Acute aflatoxin ingestion can result in death. In livestock, including poultry, swine and fishes, listlessness, poor feed conversion ratio, reduced productivity are additional signs of aflatoxin ingestion [8, 9].

and reports and by some news media outlets. Technical research has disclosed the prevalence and exposure levels in crops (e.g. maize, groundnuts, melon seeds (*egusi*), chillies, dried fish, local spices) [13–15]; in addition to biomarkers (e.g. those present in breastmilk of nursing mothers, blood serum and urine) [16, 17]. A comprehensive report of incidences have been reviewed [18]. These have revealed the presence of aflatoxins in food crops as an indicator of dietary exposure. These scientific studies have been conducted as part of academic programs, and developmental efforts in collaboration with national systems to establish exposure levels. They have majorly been for chronic exposures, and to provide empirical evidence for outbreaks caused by acute exposure. Incidences of chronic exposure are not as momentous as those for acute exposure, but they could be lifelong starting early in life. This is especially because exposure can precede birth, from foetal exposure through umbilical cord, to aflatoxin exposure very early in life (from the first 1000 days of life), via mothers' breastmilk (where the nursing mother has had dietary aflatoxin exposure), and through weaning foods made using contaminated food products [19]. Furthermore, in many parts of sub-Saharan Africa, staple food consumption is frequent and forms a constant source of dietary exposure to consumers. Limited diversity in the meals consumed increases exposure risk, especially if the food consumed is contaminated by these harmful toxins. Aside from the consumption of foods for dietary needs, recreational consumption of locally brewed beers is another risk factor contaminated cereals could form the stock material from which the brews are made from [20].

Aflatoxin Management Strategies in Sub-Saharan Africa http://dx.doi.org/10.5772/intechopen.78784 111

Converse to reports majorly on chronic exposure by technical experts, news media/communication expert reports are often based on acute exposure. Acute outbreaks have caused national alarm (such as those recorded in 1980, 2004 and 2012 in Kenya; and 2016 in Tanzania). These outbreaks of acute aflatoxicosis occurred due to the ingestion of unsuspectingly high levels of aflatoxins in maize consumed as a staple food Outbreaks were first reported as 'mysterious illness' or caused by 'toxic' or 'poisonous' food. This is due to the clandestine nature of aflatoxins. This bears similarity to the foremost global report of aflatoxicosis in 1960 called the "Turkey X' disease, where 'X' was the mysterious unknown [21]. The covert nature of aflatoxins is primarily because sensual perception of aflatoxins is nearly impossible since the toxins are invisible, tasteless and odorless when present in food crops. Management of aflatoxins during these times have called for crisis response actions that immediately forestall continued exposure.

Aflatoxin management requires multiple strategies including the following which are further discussed in details hereafter: Awareness of aflatoxins, Pre-harvest aflatoxin prevention/ reduction, Peri-harvest aflatoxin prevention/reduction, Post-harvest aflatoxin prevention/

Awareness of aflatoxins is critical to its management because information is the basis for initiating and sustaining measures to control aflatoxin exposure and associated health and

**2. Aflatoxin management strategies**

**2.1. Awareness of aflatoxins**

reduction and Post-contamination aflatoxin management.

In addition to the negative health impacts caused by aflatoxins, aflatoxins also limit income generation. This is because the import of aflatoxin-contaminated produce above regulatory limits of importing countries is prohibited. Therefore, aflatoxin contamination has been responsible for depriving the sub-Saharan region of trade opportunities. Also, trading relationships have been marred by notifications of consistent aflatoxin contamination such as through the rapid alert system of the European Union (https://ec.europa.eu/food/safety/ rasff\_en). Moreover, economies of households within the sub-Saharan region are negatively affected because household income is diverted in addressing morbidity caused by aflatoxicosis (illness caused by ingestion of aflatoxins) termed disability adjusted life years (DALYs) [10]. This reduces availability of income for more economically advantageous ventures. Therefore, aflatoxin management is critical for the health and economy of sub-Saharan Africa However, it is reported that countries build social networks of trading relationships based on achievable mycotoxin limits [11]. For example, France is a trading partner with the UK, Spain and Netherlands (among others) which have similar total aflatoxin standards of 4 ng/g. Similarly, the USA is a trading partner with Mexico, Colombia, Dominican Republic (and others) which have similar total aflatoxin standards of 20 ng/g in maize.

Aflatoxin management is critical also because in addition to environmental reasons for aflatoxin exposure, infrastructural deficits, informal market structures and improper cultural habits can introduce additional aflatoxin-exposure risks [12]. Management strategies therefore, of necessity requires multi-dimensional approaches that mitigate risks from multiple sources such as contamination risks during crop development, during harvesting and post-harvest. This chapter discusses the approaches that are necessary for aflatoxin mitigation, and those that have been used for the management of aflatoxins in sub-Saharan Africa and progress made so far. Brief mention is also made of emerging strategies for aflatoxin management.

#### **1.2. Incidences of aflatoxicosis in sub-Saharan Africa**

Aflatoxicosis may be broadly classified into **acute and chronic aflatoxicosis**. Acute aflatoxicosis refers to aflatoxin poisoning caused by ingestion of large doses of dietary aflatoxins. Chronic aflatoxicosis refers to aflatoxin poisoning caused by the ingestion of smaller amounts over extensive periods of time. Acute aflatoxicosis is severe often results in immediate fatalities. However, with chronic exposure the effects of exposure are cumulative, so exposure may be undetected in early stages because of its subsymptomatic nature. In sub-Saharan Africa, aflatoxin contamination has been reported by technical experts in academic journal and reports and by some news media outlets. Technical research has disclosed the prevalence and exposure levels in crops (e.g. maize, groundnuts, melon seeds (*egusi*), chillies, dried fish, local spices) [13–15]; in addition to biomarkers (e.g. those present in breastmilk of nursing mothers, blood serum and urine) [16, 17]. A comprehensive report of incidences have been reviewed [18]. These have revealed the presence of aflatoxins in food crops as an indicator of dietary exposure. These scientific studies have been conducted as part of academic programs, and developmental efforts in collaboration with national systems to establish exposure levels. They have majorly been for chronic exposures, and to provide empirical evidence for outbreaks caused by acute exposure. Incidences of chronic exposure are not as momentous as those for acute exposure, but they could be lifelong starting early in life. This is especially because exposure can precede birth, from foetal exposure through umbilical cord, to aflatoxin exposure very early in life (from the first 1000 days of life), via mothers' breastmilk (where the nursing mother has had dietary aflatoxin exposure), and through weaning foods made using contaminated food products [19]. Furthermore, in many parts of sub-Saharan Africa, staple food consumption is frequent and forms a constant source of dietary exposure to consumers. Limited diversity in the meals consumed increases exposure risk, especially if the food consumed is contaminated by these harmful toxins. Aside from the consumption of foods for dietary needs, recreational consumption of locally brewed beers is another risk factor contaminated cereals could form the stock material from which the brews are made from [20].

Converse to reports majorly on chronic exposure by technical experts, news media/communication expert reports are often based on acute exposure. Acute outbreaks have caused national alarm (such as those recorded in 1980, 2004 and 2012 in Kenya; and 2016 in Tanzania). These outbreaks of acute aflatoxicosis occurred due to the ingestion of unsuspectingly high levels of aflatoxins in maize consumed as a staple food Outbreaks were first reported as 'mysterious illness' or caused by 'toxic' or 'poisonous' food. This is due to the clandestine nature of aflatoxins. This bears similarity to the foremost global report of aflatoxicosis in 1960 called the "Turkey X' disease, where 'X' was the mysterious unknown [21]. The covert nature of aflatoxins is primarily because sensual perception of aflatoxins is nearly impossible since the toxins are invisible, tasteless and odorless when present in food crops. Management of aflatoxins during these times have called for crisis response actions that immediately forestall continued exposure.
