Mycetoma is a chronic, progressively destructive inflammatory disease of the subcutaneous tissues, affecting skin, muscle and bone. Mycetoma can be caused by a large variety of microorganisms, but almost always caused by bacteria or fungus. Mycetoma occurs in tropical and subtropical environments characterized by short rainy seasons and prolonged dry seasons that favour the growth of thorny bushes. Global burden is not known, but a 2013 survey reported a total of 8763 cases. Mycetoma has numerous adverse medical, health and socioeconomic consequences for patients, communities and health services in affected areas. Preventing infection is difficult, but people living in or travelling to endemic areas should be advised not to walk barefoot, as footwear and clothing in general can protect against puncture wounds.
Mycetoma is a chronic disease usually of the foot but any part of the body can be affected. Infection is most probably acquired by traumatic inoculation of certain fungi or bacteria into the subcutaneous tissue.
Mycetoma commonly affects young adults, particularly males aged between 15 and 30 years, mostly in developing countries. People of low socioeconomic status and manual workers such as agriculturalists, labourers and herdsmen are the worst affected.
Mycetoma has numerous adverse medical, health and socioeconomic impacts on patients, communities and health authorities. Accurate data on its incidence and prevalence are not available. However, early detection and treatment are important to reduce morbidity and improve treatment outcomes.
Mycetoma was first reported in the mid-19th century in Madurai, India, and hence was initially called Madura foot.
The causative organisms of mycetoma are distributed worldwide but are endemic in tropical and subtropical areas in the ‘Mycetoma belt’, which includes the Bolivarian Republic of Venezuela, Chad, Ethiopia, India, Mauritania, Mexico, Senegal, Somalia, Sudan and Yemen.
Transmission occurs when the causative organism enters the body through minor trauma or a penetrating injury, commonly thorn pricks. There is a clear relationship between mycetoma and individuals who walk barefooted and are manual workers. The disease is common among barefoot populations who live in rural areas in endemic regions but no person is exempted.
Mycetoma is characterized by a combination of painless subcutaneous mass, multiple sinuses and discharge containing grains. It usually spreads to involve the skin, deep structures and bone, resulting in destruction, deformity and loss of function, which may be fatal. Mycetoma commonly involves the extremities, back and gluteal region but any other part of the body can be affected. Given its slow progression, painless nature, massive lack of health education and scarcity of medical and health facilities in endemic areas, many patients present late with advanced infection where amputation may be the only available treatment. Secondary bacterial infection is common, and that may cause increased pain, disability and fatal septicaemia (severe infections involving the entire human system), if untreated. Infection is not transmitted from human to human.
The causative organisms can be detected by directly examining the grains that are discharged by the sinuses, Fine Needle Aspiration (FNA) or surgical biopsy. Although grains microscopy is helpful in detecting the causative organism, it is important to further identify these by culture but even then misclassification occurs. Identification by Polymerase chain reaction (PCR) is the most reliable method. There is no serological diagnostic test. Imaging includes MRI and CT scanning, but only ultrasound can be applied in the affected area. In practice, there are no point-of-care diagnostic tests for use in mycetoma-endemic villages.
The treatment depends on the causative organisms for the bacterial type; it is a long term antibiotics combination whereas for fungal type it is combined antifungal drugs and surgery. The treatment is unsatisfactory, has many side effects, expensive and not available in endemic areas.
Prevention & Control
Mycetoma is not a notifiable disease (a disease required by law to be reported) and no surveillance systems exist. There are no prevention or control programmes for mycetoma yet. Preventing infection is difficult, but people living in or travelling to endemic areas should be advised not to walk barefooted.
WHO and global response
On 28 May 2016, the 69th World Health Assembly approved a resolution (WHA 69.21) recognizing Mycetoma as a neglected tropical disease.
Elaborating a public health strategy for the prevention and control of Mycetoma requires collection of epidemiological data on burden of disease, investment in research and product development, so that cost-effective prevention, diagnosis, early treatment and case management can be practised in low-resource settings. At present, active case-finding with early diagnosis and treatment with currently available tools is the most appropriate approach for lessening Mycetoma’s disease burden.
On 24 March 2017, WHO convened an informal meeting in Geneva, Switzerland to identify the priorities for implementing WHA69.21. The areas identified are epidemiology, case management, prevention, health system strengthening and capacity building, monitoring and evaluation, research, advocacy and resource mobilization.