Point-of-Care Autofluorescence Imaging for Real-Time Sampling and Treatment Guidance of Bioburden in Chronic Wounds: First-in-Human Results

Abstract

BackgroundTraditionally, chronic wound infection is diagnosed by visual inspection under white light and microbiological sampling, which are subjective and suboptimal, respectively, thereby delaying diagnosis and treatment. To address this, we developed a novel handheld, fluorescence imaging device (PRODIGI) that enables non-contact, real-time, high-resolution visualization and differentiation of key pathogenic bacteria through their endogenous autofluorescence, as well as connective tissues in wounds.Methods and FindingsThis was a two-part Phase I, single center, non-randomized trial of chronic wound patients (male and female, ≥18 years; UHN REB #09-0015-A for part 1; UHN REB #12-5003 for part 2; clinicaltrials.gov Identifier: NCT01378728 for part 1 and NCT01651845 for part 2). Part 1 (28 patients; 54% diabetic foot ulcers, 46% non-diabetic wounds) established the feasibility of autofluorescence imaging to accurately guide wound sampling, validated against blinded, gold standard swab-based microbiology. Part 2 (12 patients; 83.3% diabetic foot ulcers, 16.7% non-diabetic wounds) established the feasibility of autofluorescence imaging to guide wound treatment and quantitatively assess treatment response. We showed that PRODIGI can be used to guide and improve microbiological sampling and debridement of wounds in situ, enabling diagnosis, treatment guidance and response assessment in patients with chronic wounds. PRODIGI is safe, easy to use and integrates into the clinical workflow. Clinically significant bacterial burden can be detected in seconds, quantitatively tracked over days-to-months and their biodistribution mapped within the wound bed, periphery, and other remote areas.ConclusionsPRODIGI represents a technological advancement in wound sampling and treatment guidance for clinical wound care at the point-of-care.Trial RegistrationClinicalTrials.gov NCT01651845; ClinicalTrials.gov NCT01378728

Improved detection of clinically relevant wound bacteria using autofluorescence image‐guided sampling in diabetic foot ulcers

“…In this study, we report a higher accuracy of CSS in identifying the presence of pathogens in DFUs compared with the results of a previous publication from our group assessing standard WL versus AF imaging of 48 chronic wounds in 28 participants (52% versus 36%). However, the accuracy of AF imaging in the present study is lower (75% versus 82⋅4%) (20). This difference in diagnostic accuracy between the previous and current studies may be due to a number of factors, including population demographics (age, gender), wound characteristics (only 54% of wounds were DFUs in the previous study versus 100% here), the prevalence of pathogenic bacteria (74⋅5% in the previous study versus 41% here) and sample size (n = 490 swabs analysed in the previous study versus n = 128 here).…”

Imaging Techniques for Clinical Burn Assessment with a Focus on Multispectral Imaging

“…In particular, a few techniques not discussed in this review, fluorescence imaging for detection of wound infection is emerging onto the wound care market. 101 In addition, research in the Terahertz regime of the electromagnetic spectrum demonstrates the ability to image a burn without removing wound dressings. 102 One important future development for burn depth imaging is predicting the conversion of healthy tissue to necrosis or apoptosis owing to burn progression.…”

Appropriate use of dressings containing nanocrystalline silver to support antimicrobial stewardship in wounds

“…Technologies that supplement clinician judgement, particularly from a microbial load perspective, will aid more targeted approach to wound infection. New guidance devices such as Moleculight i:X ™, (Moleculight Inc., Toronto, Canada), which not only measure wound surface area but can also detect fluorescent bacteria above a threshold (>10 4 cfu/g), may aid more targeted sampling and support informed treatment decisions . Moreover, this is an important bridge to drive infection diagnostics, highlighted by the UK AMR strategy and the O'Neill report as one of the key focus areas to tackle AMR.…”