Severe acute respiratory syndrome (SARS) is a life-threatening disease caused by a novel coronavirus termed SARS-CoV. Due to the severity of this disease, the World Health Organization (WHO) recommends that manipulation of active viral cultures of SARS-CoV be performed in containment laboratories at biosafety level 3 (BSL3). The virus was inactivated by ultraviolet light (UV) at 254 nm, heat treatment of 65 °C or greater, alkaline (pH > 12) or acidic (pH < 3) conditions, formalin and glutaraldehyde treatments. We describe the kinetics of these efficient viral inactivation methods, which will allow research with SARS-CoV containing materials, that are rendered non-infectious, to be conducted at reduced safety levels.
Author: Christian Tang
Imagine a world where people travel as they wish. They shake hands when they make new acquaintances, embrace when they greet close friends and elderly relatives. They do not bother to laboriously disinfect their work surfaces, or wash their hands once they have dealt with the post. They go shopping as they please and find no shortage of provisions. They work in offices, laboratories, shops, restaurants and building sites. They conduct meetings in person, and think nothing of it when they jet off to their favourite holiday destination. They do all this because a COVID-19 vaccine has been developed, rolled out and administered to the entire populace, making all the chaos of 2020 a distant memory. Everything is back to normal.
This is the ending to the coronavirus pandemic we are all hoping for, and, give or take some of the details, there is no reason why it is not possible. But even in this optimistic scenario, there is a deep fear among scientists and policy makers: what happens next time? For if there is one lesson that COVID-19 has taught us, it is that our modern lifestyles are fatally ill-suited to the emergence of novel viruses – and novel viruses there will always be. Any drugs and vaccines we develop for COVID-19 will be ineffectual against the next viral pandemic, which may well consist of a different family of virus altogether. Indeed, unless anything in our approach to pandemics changes, the next one will entail another psychologically and economically crippling lockdown while scientists find a cure – however long that takes.
Yet according to one scientist, there is something we can do differently next time. Charlie Ironside of Curtin University in Perth, Australia, is not a virologist or an epidemiologist but a physicist – one who has spent 30 years specializing in semiconductor optoelectronics. His solution: far-ultraviolet light-emitting diodes (far-UV LEDs).
Hospitals have embraced ultraviolet (UV) lights as a cleaning tool for years, using large, industrial-grade machines to decontaminate rooms. Now, smaller versions of UV sanitation lights are available to consumers looking to clean pretty much anything, from phones to toilet seats.
Here’s how these UV light sanitizers actually work.
The three main types of UV rays are UVA, UVB, and UVC. Because UVC rays have the shortest wavelength, and therefore highest energy, they are capable of killing bacteria and viruses, also called pathogens. UVC light has a wavelength of between 200 and 400 nanometers (nm). It is highly effective at decontamination because it destroys the molecular bonds that hold together the DNA of viruses and bacteria, including “superbugs,” which have developed a stronger resistance to antibiotics.
As COVID-19 continues to ravage global populations, the world is singularly focused on finding ways to battle the novel coronavirus. That includes the UC Santa Barbara’s Solid State Lighting & Energy Electronics Center (SSLEEC) and member companies. Researchers there are developing ultraviolet LEDs that have the ability to decontaminate surfaces — and potentially air and water — that have come in contact with the SARS-CoV-2 virus.
“One major application is in medical situations — the disinfection of personal protective equipment, surfaces, floors, within the HVAC systems, et cetera,” said materials doctoral researcher Christian Zollner, whose work centers on advancing deep ultraviolet light LED technology for sanitation and purification purposes. He added that a small market already exists for UV-C disinfection products in medical contexts.
A technique that zaps airborne viruses with a narrow-wavelength band of UV light shows promise for curtailing the person-to-person spread of COVID-19 in indoor public places.
The technology, developed by Columbia University’s Center for Radiological Research, uses lamps that emit continuous, low doses of a particular wavelength of ultraviolet light, known as far-UVC, which can kill viruses and bacteria without harming human skin, eyes and other tissues, as is the problem with conventional UV light.
“Far-UVC light has the potential to be a ‘game changer,’” said David Brenner, professor of radiation biophysics and director of the center. “It can be safely used in occupied public spaces, and it kills pathogens in the air before we can breathe them in.”
As more of South Florida re-opens for business following months of shutdowns, finding ways to operate safely in the era of the coronavirus is proving to be a significant challenge for many.
Dentist offices could reopen as soon as next week in Miami-Dade, but dentistry is a practice that cannot be performed while maintaining social distancing. Patients can’t even wear masks when being examined.
In order to provide an extra dose of hygiene to his office, one local dentist is making use of innovative light technology to address the problem and make his patients feel more reassured.