Laboratory study to investigate the sensitivity and specificity of a diagnostic dressing to detect burn wound infection

Burn Wound Infection (BWI) is difficult to define and detect before it manifests with clear clinical symptoms. In this paper, an ex vivo study of a prototype BWI detecting wound dressing is reported. Consenting patients with burns were recruited from four burns services in the United Kingdom, their burn infection state recorded at time of recruitment and retrospectively following treatment. Their wound dressings were used as a source of inoculating bacteria to create an ex vivo biofilm model in the laboratory with reasonable fidelity to the original microbial state of their wound. The prototype infection detecting wound dressing, which responds to cytolytic toxins secreted by bacteria, was placed on the ex vivo biofilm and the response of the dressing correlated with the clinical decision on the patients wound infection state. The study illustrated a number of broader issues with clinical BWI diagnosis, notably the absence of objective diagnostic criteria: a reference standard for BWI. The absence of such a reference standard made analysis of the relationship between the dressing response and BWI diagnosis challenging, however a point estimate of 68% sensitivity from the study suggests the potential future utility of using a sensor which detects secreted bacterial virulence factors to assist in BWI diagnosis.