The true incidence and the geographical distribution of mycetoma throughout the world is not exactly known due to the nature of the disease which is usually painless, slowly progressive which may lead to the late presentation of the majority of patients. Mycetoma has a worldwide distribution but this is extremely uneven. It is endemic in tropical and subtropical regions. The African continent seems to have the highest prevalence. It prevails in what is known as the mycetoma belt stretching between the latitudes of 15 south and 30 north. The belt includes Sudan, Somalia, Senegal, India, Yemen, Mexico, Venezuela, Colombia, Argentina and others.
The geographical distribution of the individual mycetoma organism shows considerable variations, which can be convincingly explained on an environmental basis. Areas where mycetoma prevails are relatively arid zones with a short rainy season with a relative humidity.
The organisms are usually present in the soil in the form of grains. The infecting agent is implanted into the host tissue through a breach in the skin produced by trauma caused by sharp objects such as thorn pricks, stone or splinters.
The disease is usually acquired while performing agricultural work, and it generally afflicts men between 20 and 40 years old.The disease is acquired by contacting grains of bacterial or fungal spores that have been discharged onto the soil. Infection usually involves an open area or break in the skin. Pseudoallescheria boydii is one of many fungi spp. that causes the fungal form of madura foot (see below). The disease is characterized by a yogurt-like discharge upon maturation of the infection. Hematogenous or lymphatic spread is uncommon. Infections normally start in the foot or hand and travel up the leg or arm.
Species of fungus that cause Mycetoma include: