Mycetoma is a progressive, chronic subcutaneous infectious disease. While most commonly seen in the feet, it can also occur in other parts of the body. It is caused by bacteria or fungus entering the body through a cut or wound and infecting the tissue beneath the skin. Although there are records of mycetoma dating back to ancient times, the first report in modern times came from the Indian town of Madura during the mid-19th century, so the disease was initially called “Madura Foot”. Most mycetoma patients are males between 20 and 40 years of age who are engaged in physically intensive labor, such as farming, in developing countries. Mycetoma was officially recognized as the 18th Neglected Tropical Disease at the World Health Assembly held in May 2016.
Causes of Infection
Mycetoma is divided into two subtypes based on the cause of the infection. It is known as Actinomycetoma if caused by bacterial infection and Eumycetoma if caused by fungal infection. In either case, there are multiple pathogens. Known bacterial pathogens are Nocardia brasiliensis, Actinomadura madurae and Streptomyces somaliensis. For fungal infections, there are over 20 types, but the most commonly observed is Madurella mycetomatis. Infection is caused by pathogens entering the body through a small wound, such as a thorn prick, and this is why there is a strong correlation between mycetoma patients and bare-footed laborers. Mycetoma is not contagious and is not passed from person to person.
Pathogen: bacteria (actinomycetoma) or fungi (eumycetoma)
Vector: no known vector or animal reservoir
Mycetoma usually progresses slowly, and is characterized by painless lesions under the skin which enlarge, with exudate containing bacterial or fungal grains. While the initial infection is typically in the foot, it has been known to spread to the rest of the limb. Left untreated, it can lead to physical disabilities and deformities (leading to social discrimination) and a secondary infection of the same wound can result in sepsis and death. Since most endemic regions have poor medical infrastructure and health education, and due to the slow, painless nature of the symptoms, most patients seek help only when the disease has already advanced. At this stage, surgery or amputation are the only viable treatments.
Mycetoma can be diagnosed by microscopic examination of tissue biopsy or the pus discharged by the lesions; however it is important to cultivate the causative organism to identify the pathogen. DNA sequencing and various imaging technology are also options, but in most cases, endemic regions do not have access to these advanced tests. At present, there are no suitably simple diagnosis methods available.
Besides removal of the infected area via surgery, there are medicinal treatments, but these differ depending on the pathogen. Actinomycetoma can be treated with antibiotics, with a >90% success rate. On the other hand, while azole anti-fungal drugs can be used to treat Eumycetoma, the effectiveness is limited, with a success rate of only 25-35% and a high likelihood of recurrence. As such, Eumycetoma is treated with both a lengthy course of anti-fungal drugs (over 12 months) and surgery. Cost burdens are also an issue, with over 50% of patients stopping treatment midway. This often results in recurrence, with the patients ultimately needing surgery or amputation.
There is still no viable method to control or prevent mycetoma. While complete suppression is difficult, one of the options is to advise people who live in or visit endemic regions not to walk barefoot.
Regions with high risk of infection
While the organisms that cause mycetoma are found worldwide, tropical and subtropical zones in the “Mycetoma belt” (including the Bolivarian Republic of Venezuela, Chad, Ethiopia, India, Mauritania, Mexico, Senegal, Somalia, Sudan and Yemen) are most at risk.
Estimated Number of Infected people
Mycetoma is not a disease that is required by law to be reported, and since there is no surveillance system in place to gather information, the number of patients and outbreaks are unclear. According to a study published in 2013, which was based on 50 scientific reports from 1956 onwards, 8,763 cases were reported, of which 75% were from Mexico, Sudan and India. But since these reports only represent a single hospital per country, the actual figure is thought to be far higher. A more recently published article reports the recorded number of patients up to 2017 to be 17,607 cases (Medical Mycology, 2018, 56, S153–S164).
Estimated Number of Deaths
There are no current estimates for the number of deaths due to mycetoma.
Reference (accessed September 12, 2022):
ISNTD Disease Brief, ‘Mycetoma: The case for a new entrant to the WHO’s list of Neglected Tropical Disease’; Mark Clark (April 2016)