Disinfection of needleless connectors for catheters in one second using a hand-held UV device
Background
Central Line-associated Bloodstream Infections (CLABSIs) are deadly bloodstream infections with high mortality and morbidity rates in patients with vascular catheters. In the United States, around 250,000 occur yearly. Of these, about 80,000 occur in intensive care units.
Current Approaches to Disinfection of Needleless Connectors (NC)
Disinfection of NC is performed using 70% isopropanol, chlorhexidine, or both. Alcohol and chlorhexidine disinfectants have several shortcomings in that (1) they only disinfect external surfaces, (2) active disinfection requires active scrubbing of 5 to 15 seconds and a drying time of 5 seconds for isopropanol or 20 seconds for chlorhexidine with scrubbing to disinfect effectively. Rarely, chlorhexidine can cause allergic reactions in some patients.
Use of UV Light as an Approach to Disinfection
Inadequate disinfection of NCs of a peripherally inserted central catheter (PICC) or central venous catheter (CVC) can lead to CLABSIs. Biofilm can form within the intraluminal surface of NC of a PICC or CVC. To address this problem, PuraCath Medical Inc. has developed a product to reduce the risk of bacterial transfer through NCs. The UV-Disinfection System (Firefly) consists of (1) a handheld UV LED system to disinfect; (2) the proprietary neutral displacement, UV-transmissive, NC. A rechargeable lithium-ion battery powers the handheld UV LED device.
Methods
Materials
Proprietary NCs used for these studies were manufactured by PuraCath Medical Inc. and were composed of UV-transmissive cyclic-oleic copolymers. 3M Curos caps for NCs were used as comparators (3M). Female Luer Lock Nonvented Caps (Cat # 11396) were purchased from Qonsina. The Firefly device was manufactured by PuraCath Medical Inc and contained an LED that emits light at a wavelength of 285 nm, with an average power of 45 mW/cm2.
General Procedures
The aseptic technique was used for all experiments. Positive controls were not exposed to UV-C light and negative controls were not inoculated. Controls were run concurrently with Test articles.
Agar Plates for CFU Counting
Agar plates containing media suitable for the growth of each organism were prepared for colony forming units (CFU) counts. S aureus: ATCC Medium 18: Trypticase Soy Agar/Broth; S epidermitis: ATCC Medium 18: Trypticase Soy Agar/Broth; E Coli: ATCC Medium 3: Nutrient agar or nutrient broth; P aeruginosa: ATCC Medium 3: Nutrient agar or nutrient broth; C albicans: Medium 1245: YEPD.
Inoculation of NCs
PuraCath NCs were inoculated with 10 µL of bacterial or fungal suspension at a minimum concentration of 106 CFUs/mL. The initial CFU concentration was verified by drawing serial dilutions of the suspension, plating the diluted samples, incubating the samples, and calculating the resulting CFUs.
Results
We conducted a benchtop study of NC disinfection using Firefly, using 4-log reduction in CFU as success criteria based on US Food and Drug Administration requirements. We tested 22 samples using 5 clinically relevant microbes. Our goal was to achieve a 4-log reduction in CFU with no failures in 22 samples to have 90% confidence and 90% reliability for all targeted microbes using 1 second of UV light exposure.
| Organism | Positive controls (CFUs) | Log reduction in CFUs |
|---|---|---|
| S aureus | 4.0 x 105 | 5.5 |
| S epidermidis | 4.5 x 105 | 6.1 |
| E coli | 2.1 x 105 | 5.5 |
| P aeruginosa | 6.0 x 104 | 5.7 |
| C albicans | 1.2 x 105 | 4.6 |
Discussion
We have demonstrated the efficacy of the Firefly system to disinfect NCs in the laboratory setting. The bacteria and fungi tested are those responsible for most CLABSIs in hospital patients reported to the Centers for Disease Control. The Firefly UV irradiation was effective for all the bacteria tested, and C albicans. The efficacy of the UV-C disinfection of UV-transmissive NC was equivalent to that obtained with alcohol-impregnated caps for the exterior surface.
Conclusions
This benchtop study showed that UV-C disinfection of UV-transmissive NCs using the Firefly device achieved over 4-log reduction in CFUs on the NC’s external and internal surfaces. The disinfection required 1 second of UV irradiation, in contrast to a 15-second alcohol scrub of nonalcohol-impregnated caps. The expectation is that one handheld Firefly device would be used for each patient to avoid the additional step of disinfecting the device when moving from patient to patient.
References
1. Centers for Disease Control and Prevention. National and state healthcare-associated infections report. Accessed March 22, 2024. https://www.cdc.gov/hai/data/portal/progress-report.html
2. Health Care-Associated Infections. National HAI targets & metrics. Accessed March 22, 2024. https://health.gov/hcq/prevent-hai-measures.asp
3. Center for Medicare & Medicaid Services. Hospital-acquired condition reduction program. Accessed March 22, 2024. https://www.cms.gov/medicare/quality/value-based-programs/hospital-acquired-conditions
