Mycetoma is a common health problem endemic in many tropical and subtropical regions and is characterised by devastating deformities, disability and high morbidity. It is a debilitating disease which progresses relatively silently. It has serious negative medical and socio-economic impacts on patients, families, communities and health authorities. Yet, it enjoys meagre attention across the globe, culminating in massive knowledge gaps in various aspects of mycetoma.
Mycetoma is a chronic granulomatous subcutaneous inflammatory disease caused by true fungi (eumycetoma) and certain bacteria (actinomycetoma). It affects the poorest in poor populations in the poor and most remote areas. Typically, young adult male farmers, labourers and students between 15 and 30 years old of low socio-economic status are affected most.
To date, its true incidence and prevalence are not well characterised; however, a prevalence of 14.5 per 1,000 inhabitants was reported from endemic areas recently. Likewise, the disease susceptibility, resistance and risk factors were well studied.
Traumatic inoculation of the causative organism into the subcutaneous tissue is a popular theory. In endemic areas, there is a clear relationship between mycetoma and individuals who walk barefooted and the field manual workers, but no person is exempted. No animal reservoir has been shown to be involved in transmission.
The causative organisms are isolated worldwide, but most cases of mycetoma are reported from the so-called “mycetoma belt”, which includes numerous countries such as Brazil, Chad, Ethiopia, India, Mauritania, Mexico, Senegal, Somalia, Sudan, Venezuela, Yemen, and others. The most affected geographical areas are those characterised by short rainy seasons and prolonged dry seasons.
The mycetoma clinical presentation is almost identical irrespective of the causal organism, and it is characterised by a triad of painless subcutaneous mass, multiple sinuses and discharge containing visible grains. Mycetoma usually spreads contiguously to involve the skin, deep structures and bone resulting in destruction, disfigurement and loss of function, which may be fatal. Mycetoma commonly involves the extremities, back and gluteal region, but no part is immune. The patients’ late presentation is the norm, and that is due to the mycetoma’s painless nature, the patients’ low socio-economic status, lack of health education and scarcity of medical facilities in remote areas where the disease is endemic.
The diagnosis of the causative organisms is based on their identification on histopathological sections from
surgical biopsies or cytological smears and the classical grains culture. Other useful molecular techniques, such as DNA sequencing and serological techniques, are in use.
Various imaging techniques such as radiology, ultrasound, MRC and CT scan can be used for disease extension verification. However, most of the available mycetoma diagnostic tests and techniques are invasive, expensive, of low specificity and sensitivity, and not available in mycetoma endemic regions. Patients need to travel to provincial hospitals for that.
It is still challenging and hard to treat patients with mycetoma, particularly eumycetoma. To treat eumycetoma, extensive and destructive surgery and mutilating amputation, a social stigma in developing countries and prolonged antifungal treatment are necessary. The available antifungals proved to be ineffective and have serious side effects. The currently available antifungal is itraconazole. Recently, Food and Drug Agency and European Medicine Agent have restricted the use of ketoconazole due to its serious toxicity. Treatment with itraconazole, which is not curative, lasts more than two years, at the cost of approximately $5000 per year, making it expensive for patients and health authorities in endemic areas. For actinomycetoma, a prolonged course, with a mean of 18 months, of combined antibiotics is mandatory, with a cost of $2000 per year.
In general, the treatment outcome is disappointing, characterised by a low cure rate (25%-35%) and high amputation (15%), high patient follow-up dropout (55%) and high recurrence rates (27.5%). Many mycetoma patients, due to the suboptimal management and expensive medicines and diagnostic tests, embark on traditional and alternative treatments that commonly induce massive complications. Hence, there is an urgent need for new medicines that are safe, effective and appropriate for use in rural settings.
There is no control or prevention measurement programmes for mycetoma are available worldwide, and that is due to knowledge gaps in its susceptibility, resistance and infection routine. Hence, there is a pressing need for a global epidemiological study to bridge that and to design such programmes and measurements.
The disease burden is substantial. In developing countries, the diagnosis and treatment of one patient may amount to $6000 per year with massive working days loss for the patient, the accompanying family member and the community in general. Mycetoma is an important cause of education attrition. Due to its devasting complications, the disease is considered a social stigma, particularly among the young and females.
Mycetoma is not a notifiable disease, and no surveillance systems exist. No country yet has any prevention or control programme for mycetoma. Preventing infection is difficult, but people living in or travelling to endemic areas should be advised not to walk barefoot and to wear protective shoes and clothing to protect them against puncture objects.
The research and development, community advocacy and health education programmes for mycetoma are limited, there are just a handful of organisations involved in treating the disease, and even fewer are trying to find a cure.
Hence, there is an urgent need for more awareness and advocacy on mycetoma, to develop research and development programmes, and to produce more effective, efficient medicines of short duration with fewer side effects and affordable to patients and health authorities in endemic areas. Likewise, there is a need for simple, safe, affordable field-friendly diagnostic tests of good specificity and sensitivity. Global epidemiological study is necessary to design effective and efficient preventive and control programmes.
Mycetoma was officially included in the special group of the WHO Neglected Tropical Diseases list in 2013, and the World Health Assembly 69th in 2016 endorsed a resolution to include mycetoma in the WHO Neglected Tropical Diseases list.
Further Reading
• Mycetoma Training Module
http://mycetoma.edu.sd/elearning/
• WHO Fact Sheets
http://mycetoma.edu.sd/elearning/
• Mycetoma diagnosis http://www.mycetoma.edu.sd/clinical-services/diagnoistic-facilities