Improved Detection of Infection Using Bacterial Fluorescence Imaging Reveals the True Proportion of Infected Wounds in Long Term Care Facilities

10-54% of long term care (LTC) facility patients have a chronic wound1. Often, infections develop in these wounds due to delays in detection of high bacterial loads. Delays are attributed to the low sensitivity of clinical signs and symptoms of infection2, the current standard of care (SoC), and to a lack of more objective point-of-care screening methods. Fluorescence imaging of bacteria* (FL) provides information on bacterial load ( >104 CFU/g), location and extent in wounds at point-of-care3-5. In this assessment, we evaluated whether addition of fluorescence imaging to SoC assessment would improve detection of infection-causing bacteria in wounds in LTC.

36 wounds from 27 long term care residents were assessed by SoC then underwent fluorescence imaging and wound sampling (swab) for PCR analysis. Sensitivity, accuracy, and positive predictive value (PPV) of FL was evaluated.

In 89% of wounds, bacterial loads were >106 CFU/g, suggestive of infection. FL produced high diagnostic accuracy in the LTC setting, with sensitivity of 97%, accuracy of 89% and PPV of 91%. In 56% of wounds assessed, fluorescence images revealed bacterial burden ( >104 CFU/g) where it was not otherwise suspected based on SoC. FL helped to identify wounds burdened by W.H.O priority pathogens6 including Acinetobacter baumannii (13/36 wounds), flagged an outbreak of Proteus mirabilis (detected in 32/36 wounds), and identified a wound’s presence that had been missed by SoC entirely.

This real-world evidence reveals the high prevalence of bacteria-laden wounds in the LTC setting. Addition of FL improved diagnostic accuracy compared to SoC assessment. Objective information provided by FL facilitates more timely and accurate treatment of wounds in the LTC setting, mitigating risk of outbreak or wound deterioration, and leading to better patient care.

Trademarked Items (if applicable): MolecuLight i:X

References (if applicable): 1. Leblanc et al. Lippincott Nursing Center (last visited June 2020)
2. Reddy et al. JAMA (2012)
3. Rennie et al. J Wound Care (2017)
4. Hurley et al. J Wound Care (2019)
5. Serena et al. J Wound Care (2019)
6. World Health Organization. W.H.O. Priority Pathogens for R&D of New Antibiotics (2017).