Demonstrated Infection Control Results with Antimicrobial Photodynamic Therapy
by [Angelika Vance and Carolyn Cross at Ondine Biomedical Inc.]
The team at Ondine Biomedical Inc. have been leading the worldwide charge in developing and commercializing antimicrobial photodynamic therapy (aPDT or “photodisinfection”) for the prevention and treatment of healthcare-associated and other infections with some compelling results…
Pre-surgical nasal photodisinfection: over 80% reduction in surgical site infection rates
Nasal photodisinfection has been standard of care for the past 8 years at Canada’s second-largest hospital, Vancouver General Hospital (VGH), and its affiliate, UBC Hospital, to decolonize infection-causing nasal pathogens prior to surgery. Deployed together with routine skin antisepsis, it has helped reduce the hospitals’ surgical site infection (SSI) rate more than 80% (from 2.7% to 0.44%), conservatively preventing over 1,000 SSIs and leading to millions of dollars in costs avoided annually and over 1,000 bed-days saved each year.
The impact on post spine surgery infections has been so significant (78% reduction in SSI rate; 1 infection prevented for every 18 patients treated; CAD $4.24 million in annual savings; no adverse events[1]) that nasal photodisinfection is being recommended for routine use to prevent surgical site infections. These findings, which were presented at the Canadian and North American Spine Society annual congresses, won the top research award at both.
The implementation team at Vancouver Coastal Health was recognized with the ICPIC Innovation Award of Excellence in 2013 and was asked to present its latest results (above) at ICPIC 2019 in September. Since implementing nasal decolonization into their standard pre-surgical decolonization protocols, the VGH hospitals have reduced surgical site infections by 84%.
Ondine’s nasal photodisinfection is Health Canada approved, has been granted CE Mark, and is currently going through the US regulatory approval process.
Studies currently underway
Several studies are ongoing to further demonstrate the utility of nasal decolonization using photodisinfection. These include a study to look at the effect of nasal photodisinfection in otolaryngological surgery and post-operative antibiotic use. Ongoing data is being collected using nasal photodisinfection in orthopedic surgery as well as cardiac and other procedures looking as surgical site infection rates.
Eradication of Aspergillus fumigatus in vivo
Ondine recently presented on the successful eradication of A. fumigatus in a rabbit maxillary sinus model with >99.9% reduction in recoverable fungus after sinus photodisinfection vs. control, a highly significant outcome.[2] A. fumigatus is a potentially lethal pathogen to patients with weakened immune systems and may lead to invasive pulmonary aspergillosis or chronic invasive fungal sinusitis (IFS) with risks of significant morbidity and/or mortality. Preventive measures as well as prompt diagnosis and initiation of appropriate therapy is essential.
Ondine Biomedical's President and CTO, Dr. Nicolas Loebel, presenting the nasal photodisinfection results update at ICPIC 2019 in Geneva on behalf of Vancouver Coastal Health.
Nasal decolonization: what and why
Nasal colonization can cause opportunistic and sometimes life-threatening infections such as surgical site infections or other infections in non-surgical patients that increase morbidity, mortality as well as healthcare costs. Reducing nasal pathogen colonization using topical antibiotics has been demonstrated to reduce surgical site infections and ICU infections by over 40%. Their use, however, suffers from lack of patient compliance and is associated with increased risk of antimicrobial resistance.
Photodisinfection-based nasal decolonization eliminates these issues, and importantly (unlike antibiotics) eradicates all bacteria, viruses, and fungi, including superbugs, in minutes.
Eradication of multidrug-resistant Candida auris in vitro
24-hr cultures of highly resistant C. auris strain #390 showing degree of survival post-exposure to photosensitizer (MRSAid™, Ondine Biomedical Inc., Vancouver BC) and illumination at 670 nm, 150 mW/cm2 in a biofilm model. Far left: untreated culture. Far right: C. auris #390 eradicated by Ondine's photodisinfection.
Ondine showed data [3] demonstrating high levels of photodisinfection efficacy against Candida auris in vitro, at the 5th International Conference of Prevention & Infection Control (ICPIC 2019). Photodisinfection completely eradicated (10⁶ logs) in both planktonic and biofilm forms of all clinical isolates of C. auris tested, including multidrug-resistant strains, in less than 5 minutes of treatment.[3] Experiments at sublethal photodisinfection doses demonstrated no increase in MIC to any tested antifungal. Intriguingly, the MIC of amphotericin B to C. auris decreased 8-fold after sublethal photodisinfection exposure, implying an increase in susceptibility to amphotericin B which was inherited across successive fungal generations.
With the lack of standardized screening practices worldwide C. auris has been associated with a variety of invasive fungal infections. Reports from Asia, the Far East, and the United States have detailed mortality rates of over 50% for those with invasive infections. With its predilection for the most vulnerable patients and concerns regarding antifungal resistance, C. auris has the potential to significantly impact morbidity, mortality, and health care infrastructure and finance. Current research has the potential to have a significant impact on future outcomes for patients and institutions worldwide.
References
[1] Banaszek D, Inglis T, Ailon T, et al. The efficacy and cost-effectiveness of photodynamic therapy in prevention of surgical site infection [abstract]. In: Proc. of the 34th Annual Meeting of the North American Spine Society; 2019, Sep 25-28; Chicago, Illinois, USA: The Spine Journal, Volume 19; Issue 9; S138. Abstract nr 283.
[2] Romo C, Loebel N, Meller D, Andersen R. A pilot study of antimicrobial photodynamic therapy of encapsulated Aspergillus fumigatus in a rabbit maxillary sinus model [abstract]. In: Proc. SPIE 11070, 17th International Photodynamic Association World Congress; 2019, Aug 7; Cambridge, Massachusetts, USA: Proc. SPIE 11070; 2019. Abstract nr 110708J.
[3] Cross C, Romo C, Loebel N. Antimicrobial Photodynamic Therapy for Control of the Newly Emerging Pathogen, C. auris [abstract]. In: Abstracts from the 5th International Conference on Prevention & Infection Control; 2019 Sep 10-13; Geneva, Switzerland: Antimicrob Resist Infect Control; 2019. Abstract nr P76.
Part of the IPA Newsletter Issue 5: Launching our New Format