Epidemiology of the diabetic foot in Africa

Diabetes mellitus is the most common, non-communicable chronic disease globally. In African countries, peripheral neuropathy underlies most diabetic foot complications; however, peripheral vascular disease appears to be increasing, presumably a reflection of increasing urbanisation. We conducted this study to ascertain the occurrence of foot complications among diabetes patients in the African continent. Using various keyword combinations, we searched Medline (PubMed) databases and the archives of Muhimbili National Hospital, the major teaching hospital in Tanzania, for obscure diabetes literature on diabetes in Africa. We also reviewed available non-English literature and obtained relevant translations where appropriate. We found articles encompassing years 1960-2003. Foot complications such as ulceration, infection, or gangrene were generally associated with considerable long-term disability and pre-mature mortality. Rates of complications varied by country-foot ulcers: 4-19 %; peripheral neuropathy: 4-84.4 %; peripheral vascular disease: 2.9-78.7 %; frequency of patients presenting with gangrenous foot ulcers: 0.6-69 %; foot amputation rates: 0.3-45 %. A study of diabetic patients in Tanzania showed mortality rates > 50 % among patients with severe foot ulcers, who did not undergo surgery. Other published data from Tanzania suggest that surgical intervention after the onset of gangrene may be too late to prevent death. Prevention and control programmes are needed to stem the rising occurrence of diabetic foot complications in Africa. Gangrenous diabetic feet require aggressive management and early surgical intervention. Early presentation by patients and prompt surgical intervention during less severe rather than during later stages of an ulcer may improve patients outcome and reduce mortality rates.