Category: Uncategorized

Categories : Implants and Prostheses UncategorizedTags :

Recipients of Bionic Eyes Blindsided by Obsolescence

On By ModernMedia
Source: Daniil Kuzelev on Unsplash

After the manufacturer of a bionic eye ended support, hundreds of recipients of the vision-improving implants have been left without support – “literally in the dark”, as one of them put it.

IEEE Spectrum, which first broke the story, reported that Second Sight discontinued its retinal implants in 2019. The retinal implants serve as the source of artificial vision for the users.

The publication wrote that the firm’s focus is currently on developing a brain implant known as the Orion, which also provides artificial vision. However, it only offers very limited support to the 350 or so who have the now-obsolete Argus II implants.

The system consists of a camera mounted on glasses worn by the user, which transmits video to a video processing unit (VPU), which then encodes the images into arrays of black and white pixels. The VPU then relays the pixel to an electrode array behind the retina, which creates flashes of light corresponding to the white pixels. The technology has had a long and costly road from experiment to product, starting with a lab experiment in the 1990s where stimulation of a single electrode in the retina was discovered to create a visible flash of light perceived by a blind patient. It is hugely expensive, with an estimated cost of $150,000 (R2.25 million) even before the surgery and post-surgery training. 

Implantation surgery typically takes a few hours, followed by training to help users interpret the new optical input from their implants. It is not a replacement for sight; rather it is more like a new sense. Users of the system see fleeting changes of grey which some can then use to assist with basic locomotion. However, the technology is still crude and not all benefit to the same degree. While some can make out the stripes on a pedestrian crossing, others never achieve that level of ability.

The technology also comes with some risk. In the postapproval period, 17% experienced adverse events, though this was an improvement over the 40% in the preapproval period. Since the implant can interfere with MRI scans, some have had to consider removal.

IEEE Spectrum contacted a number of patients, who voiced concern over their future. One patient, Ross Doer, said he was delighted when Second Sight told him in 2020 he was eligible for software upgrades. Yet, he heard troubling rumours. When he called his Second Sight vision-rehab therapist, “She said, ‘Well, funny you should call. We all just got laid off,’ ” he recalled. “She said, ‘By the way, you’re not getting your upgrades.’ ”

“Those of us with this implant are figuratively and literally in the dark,” he said.

Second Sight, when contacted by the publication, said that it had to reduce its workforce because of financial difficulties, and though it attempted to provide “virtual support” was unable to assist with repairs or replacements.
Benjamin Spencer, one of the six patients to receive the new Orion implant, said that it was “amazing” and he was able to see his wife for the first time. But knowing what he does now about Second Sight makes him apprehensive, and plans to have his implant removed at the end of the study period.

Speaking to the BBC, Elizabeth M. Renieris, professor of technology ethics at the University of Notre Dame, in the US, described the development as a cautionary tale.

“This is a prime example of our increasing vulnerability in the face of high-tech, smart and connected devices which are proliferating in the healthcare and biomedical sectors,” she said.

“These are not like off-the-shelf products or services that we can actually own or control. Instead we are dependent on software upgrades, proprietary methods and parts, and the commercial drivers and success or failure of for-profit ventures.”

She added that in future, ethical considerations concerning such technology should include “autonomy, dignity, and accountability”.

Source: IEEE Spectrum

Categories : Obstetrics & Gynaecology Substance Use UncategorizedTags :

Effects of Fathers’ Prenatal Alcohol Exposure Manifests in Offspring

On By ModernMedia
Source: Pixabay

Researchers have discovered that males exposed to alcohol in utero later pass on those effects to their offspring during foetal development, through reduced placental efficiency. The study appears in FASEB Journal.

Dr Michael Golding, an associate professor at Texas A&M University has spent years investigating the father’s role, with regard to drugs and alcohol, in foetal development. Studies have shown that males pass down more than just their genetics, Dr Golding said, but exactly how that process works and the its consequences are still largely unknown.

“When you look at the data from throughout human history, there’s clear evidence that there’s something beyond just genetics being inherited from the male,” Dr Golding said. “So, if that data is solid, we’ve got to start looking more at male behaviour.

“Say you had a parent who was exposed to starvation – they could pass on what you might call a ‘thriftiness,’ where their kids can derive more nutrition from less food,” he said. “That could be a positive if they grow up in a similar environment, or they could grow up in a time when starvation isn’t an issue and they might be more prone to obesity or metabolic syndromes. That kind of data is clearly present in clinical data from humans.”

Epigenetics, which is Dr Golding’s area of study of how things beyond genes, such as behaviour and environment, affect development is called. One of the big questions in the search for answers on how male prenatal behaviour can impact foetal growth has been the way these epigenetic factors manifest.

The team has shown that prenatal exposure to alcohol in males can manifest in the placenta: in mice, offspring of fathers exposed to alcohol have a number of placenta-related difficulties, including increased foetal growth restriction, enlarged placentas, and decreased placental efficiency.

“The placenta supplies nutrients to the growing foetus, so foetal growth restriction can be attributed to a less efficient placenta. This is why placental efficiency is such an important metric; it tells us how many grams of foetus are produced per gram of placenta,” said Thomas, a graduate student at Texas A&M. “With paternal alcohol exposure, placentas become overgrown as they try to compensate for their inefficiency in delivering nutrients to the foetus.”

However,while these increases happened frequently in male offspring, the frequency varied greatly based on the mother; however, the same increases were far less frequent in female offspring. Dr Golding thinks that although information is passed from the father, the mother’s genetics and the offspring’s sex are also involved.

“This is a novel observation because it says that there’s some complexity here,” Dr Golding said. “Yes, men can pass things on to their offspring beyond just genetics, but the mom’s genetics can interpret those epigenetic factors differently, and that ultimately changes the way that the placenta behaves.”

These results don’t draw a clear line in how drinking in human males prior to conception impacts foetal development, but they continue to at least point to it being a question that needs to be explored. 

Dr Golding is hoping that more questions will be asked about male prenatal behaviour so that there’s more data from which to work.

“The thing that I want to ultimately change is this stigma surrounding the development of birth defects,” Dr Golding said. “There’s information coming through in sperm that is going to impact the offspring but is not tied to the genetic code; it’s in your epigenetic code, and this is highly susceptible to environmental exposures, so the birth defects that we see might not be the mother’s fault; they might be the father’s or both, equally.”

Source: Texas A&M University

Categories : UncategorizedTags :

COVID Misinformation Less Prevalent than Believed

On By ModernMedia
Photo by Markus Winkler on Unsplash

Contrary to what might be expected, misinformation about COVID was less prevalent than for other health topics, researchers found.

Before the COVID pandemic, health misinformation was already widely spread. While all types of information about COVID (including misinformation) were popular between March and May 2020, posts about COVID were more likely to come from governments and academic institutions. Often, these posts were more likely to go viral than posts from sources that routinely spread misinformation.

“At the start of the pandemic, governments and organisations around the world started paying attention to the problem of health misinformation online,” said David Broniatowski, an associate professor at the George Washington University. “But when you compare it to what was going on before the pandemic, you start to see that health misinformation was already widespread. What changed is that, when  COVID-19 hit, governments and social media platforms started paying attention and taking action.”

The researchers collected public posts on Twitter and Facebook at the outset of the pandemic, between March and May 2020, when content about COVID was growing rapidly. They compared those to posts on other health topics from the same time period in 2019, and looked at the credibility of the websites that each post shared. More credible sources included government and academic sources as well as the traditional news media. Sources deemed “not credible” comprised conspiracy-oriented sites and state-sponsored sites known for spreading  propaganda, which were 3.67 times more likely to spread misinformation than credible sites.

“Misinformation has always been present, even at higher proportions before COVID started. Many people knew this, which makes the ensuing misinformation spread during COVID entirely predictable,” said study co-author Mark Dredze, an associate professor at Johns Hopkins University. “Had we been more proactive in fighting misinformation, we may not have been in an anti-vaccination crisis today.”

“These findings suggest that the ‘infodemic’ of misinformation is a general feature of health information online, not one restricted to COVID-19,” Broniatowski said. “Clearly there is a lot of misinformation about COVID, but attempts to combat it might be better informed by comparison to the broader health misformation ecosystem.”

Source: George Washington University

Categories : Lab Tests and Imaging UncategorizedTags :

A New Alternative to Skin Biopsies

On By ModernMedia
Source: Pixabay

A new ‘virtual histology’ technology being developed by researchers could replace many skin tissue biopsies. The technology is detailed in Light: Science & Applications. 

Histology is the microscopic study of tissues and organs through sectioning, staining, and examining those sections under a microscope. Often called microscopic anatomy and histochemistry, histology allows for the visualisation of tissue structure and characteristic changes the tissue may have undergone.

“This process bypasses several standard steps typically used for diagnosis – including skin biopsy, tissue fixation, processing, sectioning and histochemical staining. Images appear like biopsied, histochemically stained skin sections imaged on microscope slides,” said the study’s senior author, Aydogan Ozcan, Chancellor’s Professor and Volgenau Chair for Engineering Innovation of the Electrical and Computer Engineering Department at UCLA Samueli.

The technology may enable rapid diagnosis of malignant skin tumours, reducing unnecessary invasive skin biopsies and allowing skin cancer diagnosis at an earlier stage. This technology had only previously been applied to microscopy slides of unstained tissue, acquired through a biopsy. This is the first time virtual histology has been applied to intact, unbiopsied tissue.

“The current standard for diagnosing skin diseases, including skin cancer, relies on invasive biopsy and histopathological evaluation. For patients, this often leads to unnecessary biopsies and scars as well as multiple visits to doctors. It also can be costly for patients and the health care system,” said Dr Philip Scumpia, assistant professor of dermatology and dermatopathology at the David Geffen School of Medicine at UCLA and the West Los Angeles Veterans Affairs Hospital and a member of the UCLA Jonsson Comprehensive Cancer Center. “Our approach potentially offers a biopsy-free solution, providing images of skin structure with cellular-level resolution.”

The research team, led by Ozcan, Scumpia and Dr. Gennady Rubinstein, a dermatologist at the Dermatology & Laser Centre in Los Angeles, created a deep-learning framework to transform images of intact skin acquired by an emerging noninvasive optical technology, reflectance confocal microscopy (RCM), into a format that is user-friendly for dermatologists and pathologists. Analysing RCM images requires special training because they are in black and white, and unlike standard histology, they lack nuclear features of cells.

“I was surprised to see how easy it is for this virtual staining technology to transform the images into ones that I typically see of skin biopsies that are processed using traditional chemical fixation and tissue staining under a microscope,” Dr Scumpia said.

The researchers trained a neural network to rapidly transform RCM images of unstained skin into virtually stained 3D images like the H&E (haematoxylin and eosin) images familiar to dermatologists and dermatopathologists.

“This framework can perform virtual histology on a variety of skin conditions, including basal cell carcinoma. It also provides detailed 3D images of several skin layers,” said Ozcan. “In our studies, the virtually stained images showed similar color contrast and spatial features found in traditionally stained microscopic images of biopsied tissue. This approach may allow diagnosticians to see the overall histological features of intact skin without invasive skin biopsies or the time-consuming work of chemical processing and labeling of tissue.”

“The only tool currently used in clinics to help a dermatologist are dermatoscopes, which magnify skin and polarise light. At best, they can help a dermatologist pick up patterns,” said Rubinstein, who also uses reflectance confocal microscopes in clinic.

The authors said there is a way to go before clinical use, but they aim to introduce the technology at various scales alongside other optical-imaging systems. Once the neural network is “trained,” with many tissue samples and the use of powerful graphics processing units (GPUs), it will be able to run on a computer or network, enabling rapid transformation from a standard image to a virtual histology image.

This technology could usher in a new age of “digital dermatology” and change how dermatology is practised. Additionally, the research team will see if this artificial intelligence platform can work with other AI technologies to look for patterns and further aid in clinical diagnosis.

Source: UCLA

Categories : Diet and Nutrition UncategorizedTags :

Leafy Vegetable-rich Diet Could Curb Migraine Symptoms

On By ModernMedia
Source: Pixabay

It may be worth adopting a plant based diet, rich in dark green leafy vegetables, to ease the symptoms of chronic migraine, suggest doctors reporting on a case study.

Writing in BMJ Case Reports, the doctors’ recommendation comes after treating a man who suffered from migraines for 12 years and had tried medication, yoga and avoiding potential ‘trigger foods’ to no avail.

Over 1 billion people worldwide have migraines, characterised as one-sided, pulsating headaches lasting 4–72 hours, and often accompanied by sensitivity to noise and light and sometimes prodromal auras. While the condition may be treated and prevented with drugs, a growing body of evidence suggests that diet can be an effective treatment.

Six months before his clinic referral, the man’s migraines had become chronic, occurring on 18–24 days of every month. The pain was described as starting suddenly and intensely in the forehead and left temple. The pain was throbbing in nature, usually lasting 72 hours. His headaches were accompanied by sensitivity to light and sound, and nausea and vomiting. On a scale of 0–10, he scored the pain severity as 10–12 out of 10.

Blood tests showed little systemic inflammation and a normal level of beta-carotene (53 µg/dL). This is likely due to his daily sweet potato consumption, which, although high in beta-carotene, are relatively low in the nutrients responsible for the anti-inflammatory and antioxidant properties of carotenoids, the authors pointed out. These are instead found in dark green leafy vegetables, such as spinach. Systemic inflammation and oxidative stress are implicated in migraine.

The authors recommended that he follow the Low Inflammatory Foods Everyday (LIFE) diet, which is a nutrient dense, whole food, plant-based diet.

The LIFE diet includes eating at least five ounces (142g) of dark green leafy vegetables every day, drinking one 32-ounce (905g) daily green LIFE smoothie, and cutting back on whole grains, starchy vegetables, oils, and animal protein, particularly dairy and red meat.

After two months on the LIFE diet, the frequency of his migraine attacks had fallen to just 1 day a month; the length and severity of the attacks had also lessened. Blood tests showed a substantial rise in beta-carotene levels, from 53 µg/dL to 92 µg/dL.

He stopped his migraine meds and even when he tried certain ‘challenge’ foods which triggered headaches, they were less intense. At three months his migraines completely stopped, and they haven’t returned in 7.5 years.
The 60-year-old patient, whose identity was not disclosed, said: “Before I changed my diet, I was suffering six to eight debilitating migraines a month, each lasting up to 72 hours. Most days, I was either having a migraine or recovering from one.”

The man was allergic, which studies suggest contributes to migraines, and his allergies had disappeared. He was also HIV positive, also linked to migraine risk, so it is certainly possible that the man’s HIV status and antiretroviral drugs had contributed to his symptoms, the reports acknowledge, which they could not exclude.
Nevertheless they concluded: “This report suggests that a whole food plant-based diet may offer a safe, effective and permanent treatment for reversing chronic migraine.

“While this report describes one very adherent patient who had a remarkable response, the LIFE diet has reduced migraine frequency within three months in several additional patients (personal communication).”

Source: EurekAlert!

Categories : Cancer UncategorizedTags :

An Inspiration Led to Understanding Metformin’s Anti-tumour Effect

On By ModernMedia
Scientists report that metformin, used to treat type 2 diabetes mellitus, induces activation and proliferation of tumor-targeting CD8+ T-lymphocytes (CD8TIL), via mechanisms that involve the generation of reactive oxygen species in mitochondria of CD8TIL and an increase in glycolysis. Credit: Heiichiro Udono from Okayama University

Researchers in Japan have elucidated how the antidiabetic drug metformin exerts an anti-tumour effect as well.

Certain drugs like metformin have recently been found to have anti-cancer properties. Metformin appears to bolster anti-tumour immunity but the underlying immunological mechanisms were a mystery. With all the permutations and combinations of cancer, a blanket, yet targeted therapy would be ideal. 

Japanese scientists led by Professor Heiichiro Udono from Okayama University thus decided to address this oncological research question. In their recent study, they looked at how a specific subset of immune cells, called CD8+ infiltrating T-lymphocytes (CD8TIL), which specifically attack tumor cells, behaved in response to metformin. Their findings have been published as a research article in Journal for ImmunoTherapy of Cancer.

Interestingly, Prof. Udono almost gave up on his anti-cancer pursuits, when he lost his own father to cancer. However, a bolt of inspiration came at a conference: “Nearly 10 years ago, a switch turned on in my head when I attended a Keystone Symposia discussing cancer, and hypoxia, held in Banff, Alberta. I realised that we had missed addressing Warburg effect, an effect which bolsters the growth of cancer, in our previous research. So, reverting Warburg effect to normal metabolic profile in cancers became a topic that got me thinking. Surprisingly, I got a hint from the same conference that metformin may aid cancer immunity. So, we got to work!”

Prof Udono and his team got to work, meticulously conducting a series of experiments on cancer cell lines, and ‘knockout gene’ mice, searching for possible biomolecules that result in metformin-dependent anti-tumour immunity. They probed the intracellular mechanisms in CD8TIL, when exposed to metformin, and assessed different biomarkers for growth. Given that CD8TIL produces proteins called interferons to attack cancer cells, they also assessed corresponding levels.

Accordingly, the scientists found that metformin causes the generation of reactive oxygen species in the mitochondria of CD8TIL (mtROS) and increases glycolysis. They also found that mtROS activated growth pathways in CD8TIL, allowing these cells to proliferate. Notably, this is achieved through a transcription factor involved in anti-oxidative stress response, called Nrf. Though metformin did not directly cause apoptosis, ‘cell suicide’ in tumours, it did cause CD8TIL to secrete interferon-ɣ to alter the tumour microenvironment in favour death of tumour cells.

Summing up the findings, Prof. Udono said: “More than anything else, our study provides the knowledge that we can ourselves protect our body from cancer. We hope that this understanding will result in not only the reduction of cancer incidence and improve treatment, but also will help prolong our life.”

The researchers also added that these findings strongly suggest the possibility of using metformin as a drug to strengthen anti-tumour immunity in patients with cancer. The findings appear in the Journal for ImmunoTherapy of Cancer.

Source: EurekAlert!

Categories : UncategorizedTags :

Can Prozac be Used to Treat Macular Degeneration?

On By ModernMedia
Source: Unsplash

The antidepressant fluoxetine, best known as Prozac, could offer the first treatment for the leading cause of blindness among people over 50, new research from the University of Virginia School of Medicine suggests.

Researchers have found early evidence that the drug fluoxetine may be effective against atrophic (or ‘dry’) age-related macular degeneration, a condition that affects nearly 200 million people worldwide. An analysis based on bench research, mouse models and huge insurance databases concluded that patients taking fluoxetine were less likely to develop atrophic macular degeneration (AMD).

On the strength of their findings, which were published in PNAS, the researchers are urging the investigation of fluoxetine to treat AMD, possibly as an oral pill or slow-release implant in the eye.

“These findings are an exciting example of the promise of drug repurposing, using existing medicines in new and unexpected ways,” said Bradley D. Gelfand, PhD, of UVA’s Center for Advanced Vision Science. “Ultimately, the best way to test whether fluoxetine benefits macular degeneration is to run a prospective clinical trial.”

The researchers believe fluoxetine works by binding with an inflammasome, NLRP3-ASC, which triggers the breakdown of the pigmented layer of the eye’s retina.

After conducting extensive bench research, Dr Gelfand and his team tested fluoxetine and eight other depression drugs in lab mice. Fluoxetine slowed the progression of the disease, but the others did not, the scientists found.

Encouraged by their findings, the researchers looked at fluoxetine use among patients aged over 50 in two enormous insurance databases with over 100 million records. They found that people taking the drug had a “significantly” slower rate of developing dry AMD.

Their approach, which combines bench research with big-data analysis, could lead to faster repurposing of existing drugs.

“Traditional approaches to drug development can be expensive and time-consuming: On average, a new FDA-approved drug takes 10–12 years and costs $2.8 billion (present-day dollars) to develop,” the researchers wrote. “Our identification of the unrecognised therapeutic activity of an existing FDA-approved drug using big data mining, coupled with demonstrating its efficacy in a disease-relevant model, could greatly accelerate and reduce the cost of drug development.”

Dr Gelfand was involved earlier this year in using a similar approach to determine that HIV drugs known as nucleoside reverse transcriptase inhibitors, or NRTIs, may be useful against dry macular degeneration as well.

“While we have had a great deal of success with the approach of using real-world patient data, we may have only begun to scratch the surface of finding new uses for old drugs,” said Dr Gelfand, of UVA’s departments of ophthalmology and biomedical engineering. “It is tempting to think about all the untapped therapeutic potential of medicines sitting on pharmacy shelves.”

Source: University of Virginia

Categories : Diseases, Syndromes and Conditions UncategorizedTags :

Diabetes Drug Could Halve Glaucoma Risk

On By ModernMedia
Source: Pixabay CC0

GLP-1R agonists, a popular class of diabetes drugs, may also have a protective effect against glaucoma in diabetic patients, according to a new study published in the British Journal of Ophthalmology.

The researchers examined retrospective data of 1961 diabetic patients who were new users of this class of drugs and matched them to 4371 unexposed control subjects. After 150 days on average, 10 patients in the medicated group were newly diagnosed with glaucoma (0.5%) compared to 58 patients (1.3%) in the control group. These results indicate that GLP-1 receptor agonists could halve a diabetic patient’s risk of developing glaucoma.

The findings are supported by a Penn Medicine study from 2020, which found that GLP-1R agonists reduced neuroinflammation and prevented retinal ganglion cell death in mice. This class of drugs has also shown similarly protective effects against Alzheimer’s and Parkinson’s diseases in animal models, and clinical trials are underway to test the medications against neurodegenerative diseases in humans.

Glaucoma is the second leading cause of blindness worldwide, and people with diabetes are twice as likely to develop the condition.

“It was very encouraging to see that a popular diabetes medication could significantly reduce the risk of developing glaucoma, and our study suggests that these medications warrant further study in this patient population,” said Qi N. Cui, MD, PhD, with Brian VanderBeek, MD, MPH, both assistant professors of Ophthalmology at Penn.

Source: EurekAlert!

Categories : UncategorizedTags :

Nelson Mandela Bay Area Hit by Rabies Outbreak

On By ModernMedia
Source: Pexels CC0

An outbreak of rabies has hit the Nelson Mandela Bay metro, with a nine-year-old Gqeberha boy being its first victim so far.

The Nelson Mandela Bay Metropolitan Municipality (NMBMM) issued a warning calling on residents to be vigilant and to take their domestic pets for rabies vaccinations, following the death of a boy last weekend who was bitten by a dog. Health-e News received confirmation from NMBMM that the nine-year-old boy died at the Dora Nginza Hospital on Friday last week.

“We have learnt with sadness of the passing of the boy from Motherwell, who died due to rabies. We have the family in our prayers,” said Acting Mayor Luxolo Namette.

The municipality’s health services directorate deputy director Dr Patrick Nodwele said vaccinating domestic pets can be the most effective way of preventing rabies transmission to humans.

“The boy passed at Dora Nginza Hospital where it was established that he had been bitten by a dog. Our health officials, together with the Department of Agrarian Reform, have been busy these last couple months vaccinating dogs and cats in an effort to curb the virus as we know that rabies is a vaccine-preventable disease and post-bite vaccinations save lives,” Dr Nodwele told Health-e News.

Rabies causes viral encephalitis which kills up to 70 000 people a year around the world. Infected animal saliva transmits viral encephalitis to humans. Rabies is one of the oldest known diseases in history with cases dating back to 4000 years ago. For most of human history, a bite from a rabid animal was uniformly fatal. In the past, people were so scared of rabies that after being bitten by a potentially rabid animal, many would commit suicide. 

Rabies cases rose significantly over August and September, he added, which is why they are calling on residents to take their domestic pets for vaccinations. The outbreak is spread throughout the entire Nelson Mandela metro region and Nodwele said that 61 rabies specimens submitted for testing all came back positive.

So far 5254 dogs and 438 cats have been vaccinated across the metro. The municipality from time to time issues a domestic pets vaccination schedule, and is calling on residents to observe the schedule so that they bring their animals for vaccination. A vaccination and community education programme is also being run.

Dr Nodwele said the incubation period of rabies is two to three months, though with factors such as bite location and viral load, it can also vary from one week to a year.

“Initial symptoms include a fever and pain, and unusual or unexplained tingling, pricking or burning sensations at the wound site. As the virus spreads through the body to the central nervous system, progressive and fatal inflammation of the brain and spinal cord develops,” Dr Nodwele explained.

Source: Health-e News

Categories : UncategorizedTags :

Many Respiratory Diseases Are Borne by Aerosols

On By ModernMedia
Photo by Britanny Colette on Unsplash

As the COVID pandemic forced a close study of airborne transmission, new evidence has challenged the idea that many respiratory pathogens besides SARS-CoV-2 were only carried in the large respiratory droplets from coughs and sneezes of infected individuals. Rather, they also spread through virus-laden microscopic respiratory aerosols.

In a review published in Science, Chia Wang and colleagues discussed recent research regarding airborne transmission of respiratory viruses and how an improved understanding of aerosol transmission will enable better-informed controls to reduce and mitigate airborne transmission.

Most respiratory pathogens were until recently assumed to spread largely in large droplets expirated from an infectious person or transferred from contaminated surfaces. Public health recommendations in mitigating viral spread has, thus far, been guided by this understanding.

It is also known however, that a number of respiratory pathogens, such as influenza and the common cold, spread through infectious respiratory aerosols, which can remain suspended in the air, travelling further and for much longer, infecting those that inhale them.

According to a growing body of evidence, much of which gained from studying the spread of COVID, airborne transmission may be a more dominant mode of respiratory virus transmission than previously thought. Here, Wang et al. highlight how infectious aerosols are generated, travel throughout an environment and deliver their viral payloads to hosts. Before COVID, the maximum size for droplets to be classified as aerosols was 5 micrometres, but this has now been updated to 100 micrometres, because up to this size, droplets can remain suspended in the air for up to 5 seconds from a height of 1.5m and travel one metre to be inhaled by another.

The deal with this under-appreciated threat, the authors described ways to mitigate aerosol transmission at long and short ranges, including improvements to ventilation and airflows, air filtration, UV disinfection and personal face mask fit and design.

Source: News-Medical.Net