The clinical efficacy of two semi-quantitative wound-swabbing techniques in identifying the causative organism(s) in infected cutaneous wounds

Abstract

A prospective randomised controlled trial of two paired wound-swabbing techniques (Levine versus Z) was conducted to establish which method was more effective in determining the presence of bacteria in clinically infected wounds. The Levine technique involves rotating the wound swab over a 1-cm(2) area of the wound; the Z technique involves rotating the swab between the fingers in a zigzag fashion across the wound without touching the wound edge. Fifty patients were recruited into the study with acute (42%) and chronic wounds (58%). Overall, the Levine technique detected significantly more organisms than the Z technique (P≤ 0· 001). When acute and chronic wounds were analysed separately, the Levine technique again detected more organisms in both acute (P≤ 0· 001) and chronic wounds (P≤ 0· 001). We conclude that the Levine technique is superior to the Z technique and this result may be because of the Levine technique's ability to express fluid from the wound bed and thereby sampling a greater concentration of microorganisms from both the surface and slightly below the surface of the wound.