Infection of foot ulcers with Staphylococcus aureus associated with increased mortality in diabetic patients

Diabetic patients with foot ulceration have a poorer prognosis than those without ulceration. The reason for this is unclear, but there is considerable interest in the putative links between infection and atherogenesis, and it is notable that diabetic foot ulcers (DFU) are often infected with Staphylococcus aureus and the main cause of death in DFU patients is ischaemic heart disease. We examined the 5 year survival of 71 diabetic patients who presented with foot ulcers that were newly infected (Sa group, n = 56) or not infected at all during the study period (non-Sa group, n = 15) with S. aureus. Twenty-nine patients (52%) infected with S. aureus died compared with three patients (20%) whose foot ulcers were not infected with S. aureus. The patients in the two groups were similar in age and duration of diabetes. The overall five year mortality rate was 10.4% per year for those infected, significantly higher than the average of 4.0% for patients without infection (p = 0.015). None of the patients was bacteraemic or died directly from sepsis. Infection of DFU by S. aureus may increase the risk of death in diabetic patients.