Fungal pathogens are a growing threat globally (Bongomin et al. 2017). They are ubiquitous in nature and occur throughout the many climatic conditions found in Africa (Table 64.1). There are two principal fungal cell forms – yeasts and moulds. Yeasts are single cells, which reproduce by a process of budding to give rise to single daughter cells. Mycelial or mould fungi form chains of cells. The dimorphic fungi may exist in either yeast or mycelial phase. Fungi cause infections by either exposure to a high burden (load) of the organism or by immunosuppression on the part of the host. Fungi can cause diseases in different ways: through the production of toxins or mycotoxins, the possession of sensitizing antigens (allergens), or the invasion of tissue.