A disease is any condition which results in the disorder of a structure or function in a living organism that is not due to any external injury. The study of disease is called pathology, which includes the study of cause. Disease is often construed as a medical condition associated with specific symptoms and signs. It may be caused by external factors such as pathogens or by internal dysfunctions, particularly of the immune system, such as an immunodeficiency, or by a hypersensitivity, including allergies and autoimmunity.
Before the curing of a strong disease, Even in the instant of repair and health, The fit is strongest; evils that take leave, On their departure most of all show evil.
William Shakespeare, King John (1598), Act III, scene 4, line 112.
Africa is the world's second most-populous continent after Asia and has a huge need for energy and feedstock supply. African food and agricultural waste provides an excellent substrate for biorefinery processes for the production of valuable, sustainable products, including biofuel.