Reduction in the prevalence of methicillin-resistant Staphylococcus aureus in tissue and wound swab samples taken from outpatients attending a specialist diabetic foot clinic 2005-2021.

Abstract

To assess annual change in prevalence of methicillin resistant Staphylococcus aureus (MRSA) from tissue and wound swab samples from foot ulcers (DFUs) in people with diabetes between 2005 and 2021. A retrospective analysis of everyone with MRSA positive wound or tissue swabs taken from our specialist multidisciplinary foot clinic between July 2005 and July 2021. A total of 406 MRSA positive isolates from DFU swabs were identified from 185 individuals attending the foot clinic. There were 22 hospital-acquired infections (HAIs) and 159 community-acquired infections (CAIs). Fifty-two per cent (n= 37) of these individuals from 2010 to 2021 (n= 71) had presence of at least three risk factors for MRSA. The total number of swabs sent was 6312 from 1916 individuals living with diabetes. Annual MRSA DFU prevalence peaked in 2008 at 14.6% (n= 38), decreased in 2013 to 5.2% (n= 20) and did not exceed 4% (n= 6) from 2015 to 2021. Hospital MRSA was lowest in 2021 (n= 211), a 76% fall from 2007 (n= 880). Incidence of MRSA HAI from 2015 to 2021 ranged from 5.4% (n= 14) in 2020 to 11.5% (n= 41) in 2018. Prevalence of MRSA in DFU infections treated as outpatients is decreasing in line with falls in hospital acquired blood-borne infections and with overall hospital MRSA incidence. This is likely a reflection of the combination of interventions, including stringent antibiotic prescribing and decolonisation strategies. Reduction in prevalence should have positive impact on outcomes in people living with diabetes, reducing the complication of osteomyelitis and necessity for long-term antibiotic administration.