Mycetoma in Uganda: A neglected tropical disease

Mycetoma is considered a neglected tropical disease globally. However, data on its burden and the associated complications in Uganda are limited. Hence we aimed to estimate its burden in Uganda. Firstly, a systematic PubMed search for all studies of any design on mycetoma in Uganda without restriction to the year of publication was conducted. A retrospective review of all the biopsy reports at the Pathology Reference Laboratory, Department of Pathology, Makerere University, Kampala, Uganda from January 1950 to September 2019 was conducted to identify any reports on mycetoma histological diagnosis. During the 70-years study period, 30 cases were identified by the literature review, with 249 additional cases identified by review of biopsy reports (total of 279 cases). The average incidence was estimated at 0.32/100,000 persons and prevalence of 8.32/100,000 persons per decade. However, there was a general decline in the number of cases detected recently. Males and the age group of 21-30 years were the most affected by mycetoma in Uganda, and only 7% of the cases were children. The highest number of cases was recorded from Kampala (n = 30) and Jinja (n = 19) districts. The majority of the cases (68%) were referred from surgical units. The foot was the most affected part of the body (72%). Ten per cent of the cases had bone involvement of which 58% required amputation. Fungi were the most common causative agents (89%) followed by Nocardia species (5%) and Actinomycetes (4%). The index of clinical suspicion of mycetoma was low (45%) with a very large differential diagnosis. Mycetoma is a relatively rare disease in Uganda, mostly caused by fungi, and there is a big gap in data and epidemiological studies. More systematic studies are warranted to define the true burden of mycetoma in Uganda. Author summary Recently, the World Health Organisation recognized mycetoma, a chronic, progressively destructive morbid inflammatory disease usually of the foot as a neglected tropical disease. However, mycetoma is not a notifiable disease and thus the global burden of the disease remains poorly defined. It is therefore important that any collection of available data on this disease is brought forward to highlight the extent and magnitude of the burden of mycetoma. We retrospectively gathered data on the burden and aetiology of mycetoma in a country (Uganda) within the mycetoma belt based on histological diagnosis and systematic review. We found that fungal pathogens are the most common cause of mycetoma in this region. However, the distribution of the lesions is consistent with global data with the foot being the most affected site. We also noticed that clinicians have low index of clinical suspicion for mycetoma leading to under-diagnosis. Mycetoma is uncommon but not rare in Uganda; more research is obligatory to precisely define the distribution and determinants of the disease as well as primary and secondary preventative measures in endemic areas.