Microbial investigation of venous leg ulcers

To investigate microbiology laboratory reporting policies, whether practitioners working in primary care adhered to the relevant guidelines when submitting swabs from venous leg ulcers (VLUs), and the impact of laboratory reports on antibiotic usage forVLUs.

Questionnaires were sent to all microbiology laboratories in England and Wales, and to clinicians who had submitted VLU swabs to one laboratory.

Ninety-five (47%) laboratories responded. Laboratories processed a mean of 7.3 leg ulcer swabs/100,000 population/week but were often unable to identify the leg ulcer aetiology from the clinical details provided. All laboratories stated that they routinely reported group A haemolytic streptococci and meticillin-sensitive and resistant Staphylococcus aureus; 75% always reported antibiotic susceptibility for these isolates. The majority reported other beta-haemolytic streptococci. A total of 126 clinicians (64%) returned their questionnaires; 100 had confirmed in their swab submission that the ulcer was of venous aetiology and so were included in the analysis. Eighty per cent of the swabs were submitted in accordance with guidelines, with increased pain (61%) being the most common reason. Discharge/exudate (52%) and malodour (41%) were common reasons for swab submissions, even though the guidelines do not cite them as clinical signs of infection. Reporting of antibiotic susceptibilities was associated with increased antibiotic usage.

Clinicians in primary care generally adhere to guidelines when submittingVLU specimens for microbiological investigation. Clinicians need to include clinical information with the swab so that laboratories can interpret the microbiology results. To reduce the use of antibiotics in the management ofVLUs, laboratories need to be selective in their organism and antibiotic-susceptibility reporting.