CHAPTER ONE

1.1       Introduction

CHAPTER TWO

2.1       What are Aflatoxins

2.2       Types of Aflatoxigenic Fungi and their Toxin

2.3       Factors Influencing the Growth of Aflatoxin in West Africa

2.3.1   Fungi Interaction

2.3.2   Environmental Factors

CHAPTER THREE

3.0       Aflatoxin Contents in Foods and Feed in West Africa

3.1       Aflatoxin Contents in Raw Agricultural Products in West Africa

3.1.1   Nuts and Oil Seeds

3.1.2   Cereals

3.2       Aflatoxin Contact in Animal Feeds 

3.3       Aflatoxin Contacts in Vegetables

3.4       Fruits

3.5       Roots and Tubers

3.6       Milk and Milk Products

3.7       Other Foods.

CHAPTER FOUR

4.1       Harmful Effect of Aflatoxins

4.2       Human Health Implications to AF Exposure in West Africa

4.3       Animal Health Implications to AF Exposure in West Africa

4.4       Economic loss due to Aflatoxin contamination in West Africa

CHAPTER FIVE

5.1       Aflatoxin legislation in Food in West Africa

5.2       Aflatoxin Management Strategies Applicable in Africa

5.2.1   Agricultural Practices

5.2.2   Management of Insect Infestation

5.2.3   Pre & Post Harvest Operations

5.2.4   Food-based Strategies

5.2.5   Application of HACCP Systems

5.3       Conclusion

            In African countries, agricultural produce are susceptible to fungal infections which result in mycotoxin contamination due to poor agricultural practices and these mycotoxins are toxic secondary metabolites produced by fungi in agricultural products that are susceptible to mould infestation and can be classified according to their fungal origin, chemical structure and biological activity (Okello et al., 2010). They mycotoxins are mostly produced by fungi belonging to the genera, Aspergillus, Fusarium and Penicillium. The Food and Agriculture Organisation estimates that one quarter of the world’s food crops are affected by mycotoxins (CRA, 2011).

            Over 200 mycotoxins have been reported but only those occurring naturally in foods are of significance in food safety and aflatoxins are the most widely studied because they are dangerous mycotoxins and out of the 400 known mycotoxins, Aflatoxins B1 (AFB1), B2 (AFB2), G1 (AFG1) and G2 (AFG2) which are the four major groups of Aflatoxins are the most significant mycotoxins in foods and feeds ((Negash, 2018).

            Aflatoxins are secondary metabolites primarily produced by the fungi Aspergillus flavus, Aspergillus parasiticus Speare and to a lesser extent Aspergillus nomius (Hell and Mutegi, 2011). They are of economic and health importance because of their ability to contaminate human food and animal feeds, in particular cereals, nuts and oilseeds (Kaaya and Warren, 2005). According to Saad (2015), the economic impact of aflatoxins is derived directly from crop and livestock losses due to flatoxins and directly from the cost of regulatory programs designed to reduce risks to human andanimal health. The Food and Agricultural Organisation (FAO) estimates that 25% of the world’s crops are affected by mycotoxins, of which the most notorious are aflatoxins. Apart from the economic loss, Aflatoxin are dangerous to human health because of their highly toxic, carcinogenic, teratogenic, hepatotoxic and mutagenic characteristics. There is a high risk of Hepatitis B and Hepatitis C carriers developing liver cancer when they are exposed to aflatoxin and due to the toxic effects of AFB1, it has been classified as group 1, as a human carcinogen by the International Agency for Research on Cancer(Costanzo et al., 2015; IARC, 2015).

            Although, aflatoxin contamination is a serious problem in developing countries, it is most common in Sub-Sahara Africa because of the warm and humid climates (Dohlman, 2004). In addition, aflatoxins contamination rate can also be enhanced by the inadequate conditions of drying such as sun drying on the floor, on the sidewalks and extended drying times. Also, storage practices such as unhygienic condition and an instable environmental conditions (Akpo-Djènontin et al., 2016). Darwish et al. (2014) reported that aflatoxins are the most common mycotoxins (43.75%) in Africa followed by fumonisin (21.87%), ochratoxins (12.5%), zearalenone (9.38%), deoxynevalenol (6.25%) and beauvericin (6.25%). They reported high levels of aflatoxin in samples collected from several African countries including South Africa, Lesotho, Egypt, Tunisia, Morocco, Sudan, Tanzania, Zambia, Uganda, Kenya, Ethiopia, Nigeria, Ghana, Benin, Mali, Togo and Bourkina Faso.

            Many of these African countries stated above have started to set up prevention, control and surveillance strategies to reduce the incidence of Aflatoxin in foods but the available information on the incidence, public health importance, prevention and control of Aflatoxins in is still lacking because of limited monitoring systems and failure to adopt preventive and control measures (Darwish et al., 2014). That is why this review will update and discuss the available information on the Aflatoxin contents in West Africa with the aim of outlining the factors that influence the growth of Aflatoxins in West Africa and discussing the human and animal implications to Aflatoxin in West Africa. Also, various strategies applicable to the management of Aflatoxins in West African will be highlighted.