Geographical Distribution.—The name Madura foot takes its origin from the great prevalence of the affection about Madura, in the Madras Presidency of India. It is less frequent in other parts of India. It also occurs in Ceylon. The disease is rather widespread in Africa, having been reported from Algiers, Tripoli, Tunis, Egypt and the Sudan as well as from Madagascar. Cases have also been reported from Italy and Greece in Europe and from the West Indies and some of the South American countries. Several cases have been reported from North America and Sutton, in 1913, reported two cases from Kansas, one in a Mexican and one in a native of Texas.
Etiology and Epidemiology
Etiology.—The disease is caused by the penetration of certain species of fungi into the tissues of the foot, although rarely the hand or some other part of the body may be affected. These species of fungus develop in granulomatous areas from which sinuses lead to the surface of the foot, in the discharges from which are found small granules resembling those found in the discharges from actinomycosis lesions.
As a rule only one kind of fungus is found in a single case. The most common infection is that due to Discomyces madurae (Nocardia madurae) which is the fungus of the fish-roe-like granules of the pale or white variety of mycetoma. These, like the fungus of actinomycosis, Discomyces bovis, show a felted mycelium in the center and peripheral club-like structures. These granules are yellowish-white and vary in size from a pin’s head to a small pea. The mycelial threads are very narrow, 1 to 1½ microns. It grows aerobically and the cultures show slender mycelial threads which are Gram-positive. This is the organism of Carter’s white mycetoma.
Other species of the pale, white or ochroid group of mycetoma fungi are Indiella mansoni (Brumpt’s white mycetoma), Nocardia asteroides (Musgrave and Clegg’s white mycetoma), Sterigmatocystis nidulans (Nicolle’s white mycetoma) and several others.
The cases caused by the black varieties are more rare and are characterized by the presence in the discharges from the sinuses of black gunpowder-like grains.
These hard, brittle, irregular grains are caused by various species of fungi of which the best known is Carter’s black mycetoma (Madurella mycetomi). This species was cultured by Wright and first shows a grayish growth, later becoming black. Other black varieties of mycetoma are due to various other fungi. Bouffard’s black variety is caused by Aspergillus bouffardi. DeBeurmann’s black mycetoma has as cause Sporotrichum beurmanni.
Besides the white and black varieties we also have a red variety of mycetoma. The fungus grains are quite small and reddish in color. It is not an uncommon infection in certain parts of Africa, as Senegal. The cause is Nocardia pelletieri.
Boyd and Crutchfield have noted an ascomycete in an American case, with white granules, to which has been given the name Alleschiria boydii.
Epidemiology.—We know very little about the occurrence of these mycetoma fungi, other than in man. It is thought that such fungi lead a saprophytic existence on thorns or blades of grass or spine-like grains of various cereals. Thus Nicolle’s case in Tunis started from a puncture wound by a grain of barley.