Antimicrobial efficacy and inactivation kinetics of a novel LED-based UV-irradiation technology.

BACKGROUND: Ultraviolet (UV)-light-emitting diodes (UV-LEDs) are energy efficient and of special interest for the inactivation of micro-organisms. In the context of the coronavirus disease 2019 pandemic, novel UV technologies can offer a powerful alternative for effective infection prevention and control. METHODS: This study assessed the antimicrobial efficacy of UV-C LEDs on Escherichia coli, Pseudomonas fluorescens and Listeria innocua, as well as severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), human immunodeficiency virus-1 (HIV-1) and murine norovirus (MNV), dried on inanimate surfaces, based on European Standard EN 17272. RESULTS: This study found 90% inactivation rates for the tested bacteria at mean UV-C doses, averaged over all three investigated UV-C wavelengths, of 1.7 mJ/cm2 for E. coli, 1.9 mJ/cm2 for P. fluorescens and 1.5 mJ/cm2 for L. innocua. For the tested viruses, UV doses <15 mJ/cm2 resulted in 90% inactivation at wavelengths of 255 and 265 nm. Exposure of viruses to longer UV wavelengths, such as 275 and 285 nm, required much higher doses (up to 120 mJ/cm2) for inactivation. Regarding inactivation, non-enveloped MNV required much higher UV doses for all tested wavelengths compared with SARS-CoV-2 or HIV-1. CONCLUSION: Overall, the results support the use of LEDs emitting at shorter wavelengths of the UV-C spectrum to inactivate bacteria as well as enveloped and non-enveloped viruses by exposure to the appropriate UV dose. However, low availability and excessive production costs of shortwave UV-C LEDs restricts implementation at present, and supports the use of longwave UV-C LEDs in combination with higher irradiation doses.

Treatment of sialorrhoea with ultrasound guided botulinum toxin type A injection in patients with neurological disorders.

OBJECTIVES: To investigate the safety and efficacy of ultrasound guided botulinum toxin type A (BTX-A) injections into salivary glands for the treatment of sialorrhoea in patients with neurological disorders. METHODS: The parotid and submandibular glands of 10 patients were injected with BTX-A using ultrasound guidance. Before injection, the baseline rate of salivation was assessed using a visual analogue scale. Postinjection, assessments were repeated at regular intervals for up to 1 year. RESULTS: Of the 10 patients treated, nine (90%) reported a subjective reduction in salivation post-treatment and one patient (10%) found no improvement. Visual analogue scale scores showed a reduction of 55% in the mean rate of salivation for all patients and a reduction of 60.8% for the group of responders. No serious adverse events occurred and no procedure related complications were reported. CONCLUSIONS: This is the first study to report (1) the injection of BTX-A (BOTOX) into both parotid and submandibular glands, and (2) the use of ultrasound guidance during the administration of BTX-A into salivary glands. The results suggest that the technique is safe and that BTX-A injections are effective for the treatment of sialorrhoea in patients with neurological disorders.