Highlighting the effectiveness of the COVID-19 vaccines could hold key to converting doubters

UNIVERSITY OF BRISTOL

Research News

Informing people about how well the new COVID-19 vaccines work could boost uptake among doubters substantially, according to new research.

The study, led by the University of Bristol and published in the British Journal of Health Psychology, shows the importance of raising awareness of vaccine efficacy, especially if it compares very favourably to another well-established vaccine.

The research focused on adults who were unsure about being vaccinated against COVID-19. Those who were given information about the vaccine's efficacy scored 20 per cent higher on a measure of willingness to be vaccinated, compared to those who received no information. This improved receptivity increased by as much as double among survey respondents who were also given information about how COVID-19 vaccines perform in comparison to the annual flu vaccine.

Lead author Professor Colin Davis, Chair in Cognitive Psychology at the university's School of Psychological Science, said: "The general positive effect of providing key information is not surprising, as we knew already that people's perception of the effectiveness of a vaccine is an important factor in their vaccination intentions. But the extra benefit of providing comparative information is a novel finding which underscores the vital role of communication in improving vaccine uptake."

The findings come from two surveys of UK adults, aged between 18 and 85, last December. The first survey of 2,400 people revealed that 65 per cent agreed or strongly agreed they would have the COVID-19 vaccine, which at the time wasn't widely available. A further 12 per cent were equally sure that they would not take the vaccine. However, in the middle range were around a quarter (23 per cent) of respondents who expressed reservations and uncertainty about whether they would be vaccinated.

A second survey of 481 of those fence-sitters followed, which aimed to discover whether providing certain relevant information might nudge them to overcome their hesitancy and be more inclined to be vaccinated.

When no information was given, the majority of the participants were unsure about having the vaccine. Confidence levels grew by some 20 per cent when they were told of the overwhelming efficacy of the Pfizer and Moderna vaccines, 95 per cent and 94 per cent respectively at the time. Their likelihood of being vaccinated grew by a similar margin again, when the information about the COVID-19 vaccine also stated the effectiveness of the flu vaccine over the past 15 years, according to the US Centers for Disease Control, which stands at some 40 per cent.

"The findings show the positive potential of the contrast effect. Pointing out factual comparisons can be helpful when making a decision, particularly about something new. People value evidence-based information and this can provide affirmation and reassurance for cautious groups," Professor Davis said.

"It's also important to note the information we provided about the lower effectiveness of the flu jab did not change people's intention to have the flu vaccine. Perception of the flu vaccine benefits from its familiarity and an established sense of safety and efficacy. By positively associating the COVID-19 vaccine with the well-known flu jab, people are reminded that vaccines work and they are safe."

The latest figures show vaccine uptake is slowing. Over the last two months the average number of vaccine doses being administered daily has dropped from over half a million doses a day to just under a third of a million. This reflects a much lower rate of uptake among younger groups. In England while at least 95 per cent of 55 to 79-year-olds have had their first dose and at least 80 per cent of those aged 35 and above, the figure drops to some 76 per cent among 30 to 35-year-olds, 65 per cent for 25 to 29-year-olds, and just 57 per cent of 18 to 24-year-olds, according to latest NHS England data.

Professor Davis said: "Younger people perhaps perceive themselves to be less vulnerable to COVID-19 virus. While mortality rates are fortunately much lower in this age group, exposure to the virus carries the danger of long-COVID in people of all ages. By getting vaccinated young people can protect themselves and also reduce transmission levels in the population as a whole. The vaccination campaign is by no means over and this study shows the importance of informed and targeted communication."

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Paper

'Efficacy information influences intention to take COVID-19 vaccine' by Colin J. Davis et al in the British Journal of Health Psychology

Notes to editors

Professor Colin Davis is available for interview. To arrange this, please email Prof Davis: pscjd@bristol.ac.uk and Victoria Tagg, Media & PR Manager (Research), University of Bristol: victoria.tagg@bristol.ac.uk

 

Supermarket model to guide safer shopping amid pandemic

SKOLKOVO INSTITUTE OF SCIENCE AND TECHNOLOGY (SKOLTECH)

Research News

IMAGE: LEFT: SOCIAL FORCES EXERTED ON AN INDIVIDUAL SHOPPER. RIGHT: A FRAGMENT OF THE SUPERMARKET MODEL view more 

CREDIT: SKOLTECH

A Skoltech team has developed a model for assessing infection risks for supermarket customers. The researchers believe that their model will help formulate scientifically backed rules for safe shopping during the pandemic. The paper was published in PLOS One.

The team included professor Maxim Fedorov, who serves as Skoltech's Vice President for Artificial Intelligence and Mathematical Modeling, and a research group led by professor Nikolai Brilliantov -- the Director of the Skoltech Center for Computational and Data-Intensive Science and Engineering (CDISE).

The composite model presented in the paper incorporates a social forces model that describes customer motions and interactions with other shoppers or obstacles and is known to realistically reproduce waiting lines and congestions in confined spaces, such as stairs, and customers' behavior during emergency evacuation. The approach is based on calculating several "forces" (see image), each describing a customer's tendency to maintain a comfortable speed, approach a target, avoid obstacles, etc.

Other components describe the purchasing strategy and retail space layout. Customers are known to behave differently, depending on the place they visit: a small shop, a supermarket, or a cafe. The team used customer behavior scenarios specific to supermarkets and several layouts with varying numbers of intersections and bottleneck widths. Finally, the team proposed a model of infection transmission by virus-containing aerosol droplets.

The researchers used their composite model in multivariate numerical simulations to assess infection risks depending on several factors, such as average customer density, social distancing, behavior scenarios, use of masks, and retail space geometry. It turned out that the infection rate is primarily determined by social distancing, and to a much lesser extent, by the supermarket layout or customer strategy.

Curiously enough, the team discovered that increasing customer density has only a slight positive effect on sales, so filling the store to the limit makes little sense not just epidemiologically but economically, too.

"The functional version of our model, which we have made publicly available, can be used to assess the effects of various factors on the risk of infection. For example, you can optimize a store's operations in the pandemic environment by controlling customer flow, relocating specific items, and reconfiguring the retail area. Although our selection of layouts did not reveal a noticeable effect of space configuration on infection spread, geometry may be an important factor in other cases," Alexey Tsukanov, a co-author of the paper, comments.

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How well do US consumers understand their dairy purchases?

New research in the Journal of Dairy Science® examines consumer knowledge of dairy processing terms on product labels

ELSEVIER

Research News

Philadelphia, July 13, 2021 - Consumers may have less trust in food processes that they don't understand, and animal-based foods may be subject to more uninformed scrutiny than other foods due to consumers' perception of higher risk. Dairy producers can benefit from understanding how consumers interpret unfamiliar terms and claims on dairy product labels. In a new study appearing in the Journal of Dairy Science®, scientists from North Carolina State University conducted interviews and surveyed more than 1,200 consumers regarding their knowledge of and attitudes toward dairy processing terms that may appear on product labels.

Only about a third of respondents reported that they always or often read labels before purchasing dairy products; however, product labels are the primary source of information about food purchases used by consumers. This is reflected by the fact that only 24 percent of respondents were familiar with microfiltered milk, and no respondents could recall seeing the term on dairy product labels. Despite this, 20 percent expressed a negative opinion of it.

"Our survey data align with previous work that suggests the majority of dairy product consumers find both milk and cheese healthy and natural," said corresponding author MaryAnne Drake, PhD, North Carolina State University, Raleigh, NC, USA. "However, adding processing-related terms to 'milk' lowered average agreement that the resulting product was natural or healthy." Overall, agreement responses suggest that although overall dairy product consumers have a positive view of milk, processing terms introduce uncertainty that may lead to questioning this evaluation.

Providing education about processing terms improves consumer understanding and perception of those terms on labels. Before reading a definition of ultrafiltration and microfiltration, 83 percent of respondents were unfamiliar with the terms. After reading the definition, 97 percent of participants indicated that their understanding had changed. The majority of participants viewed ultrafiltered and microfiltered milk more positively and were more likely to purchase these products.

"Processing-related descriptors in ingredient statements are likely to be overlooked, especially on the labels of products with which consumers already feel familiar. However, consumers may express caution when they are made aware of unfamiliar processing terms," added Drake.

The study suggests that explaining processing-related terms using simple terms may increase positive perception among consumers. On-package education and other marketing messaging should be investigated further.

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The impact of COVID-19 on food-shopping behavior for food-insecure populations

Differences in shopping behavior highlight another health disparity for lower-income individuals during the COVID-19 pandemic

UNIVERSITY OF CONNECTICUT

Research News

The COVID-19 pandemic changed just about every aspect of normal life, including how we bought food.

While grocery stores remained open as an essential business and thrived financially throughout the pandemic, this prosperity did not translate to a consistent and sufficient food supply for many customers. Researchers have found that, on average, people went to the grocery store less frequently and spent more per trip during the pandemic.

Ran Xu, professor of allied health sciences in the College of Agriculture, Health, and Natural Resources, was interested in seeing if this trend applied to people who are food-insecure. COVID-19 exacerbated food insecurity for many. Pandemic-related job loss and other factors also led to an increase in overall rates of food insecurity.

"Because of how COVID-19 hit the economy, more people were suddenly food-insecure, and we needed more research on that," Xu says.

Xu and collaborators recently published a paper in Public Health that evaluated how perceived risk aversion, resource scarcity, and the consumers' food security status affected food procurement behaviors during this moment of national strife. They found that like food-secure individuals, food-insecure individuals made fewer grocery shopping trips due to concerns about contracting COVID-19. But, unlike food-secure individuals, they did not increase spending per trip.

"We think this is a serious issue that shows that COVID-19 impacts different populations differently," Xu says. "The findings we have are worrisome."

The researchers focused on food-insecure individuals who have considerable financial difficulty in procuring food.

They measured food insecurity according to two measures from the USDA's longer food insecurity survey. They asked respondents if they worried their food supply would run out before they had money to buy more, and if the food they bought just didn't last and they didn't have money to get more.

Then, the researchers evaluated participants' food shopping behaviors, such as types of stores they patronize, frequency of trips, and average food expense. They compared these measures with their shopping experience before the pandemic.

Their results showed that, of the 2,500 respondents from around the country, food-secure individuals tended to spend more per trip to stockpile food, reduce the potential for COVID-19 exposure, and prepare for food shortages. But food-insecure individuals could not prepare in the same way as they had much more constrained budgets and resources. Although food-insecure people made fewer grocery shopping trips due to concerns about contracting COVID-19, unlike food-secure people, they did not increase spending per trip.

The team conducted the study in May 2020, during the height of the pandemic in the U.S.

These findings show that the pandemic exacerbated the disparity between food-secure and insecure people.

Food insecurity has serious health consequences. Lack of access or lack of reliable access to nutritious foods contributes to a host of diseases including diabetes and cardiovascular disease.

"Food has everything to do with our health," Xu says. "Food insecurity adds another layer to that."

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The rat's whiskers: multidisciplinary research reveals how we sense texture

Mathematicians and neuroscientists achieve breakthrough in understanding how whiskers 'amplify' texture

UNIVERSITY OF BRISTOL

Research News

 

IMAGE: THE TAPERING OF THE WHISKER HAS THE EFFECT OF AMPLIFYING TINY HIGH-FREQUENCY MOTIONS INTO APPRECIABLE PULSE-LIKE CHANGES IN FORCES AND MOVEMENT AT THE WHISKER FOLLICLE. view more 

CREDIT: NATURE SCIENTIFIC REPORTS

How we sense texture has long been a mystery. It is known that nerves attached to the fingertip skin are responsible for sensing different surfaces, but how they do it is not well understood. Rodents perform texture sensing through their whiskers. Like human fingertips, whiskers perform multiple tasks, sensing proximity and shape of objects, as well as surface textures.

Mathematicians from the University of Bristol's Department of Engineering Mathematics, worked with neuroscientists from the University of Tuebingen in Germany, to understand how the motion of a whisker across a surface translates texture information into neural signals that can be perceived by the brain.

By carrying out high precision laboratory tests on a real rat whisker, combined with computation models, the researchers found that whiskers act like antennae, tuned to sense the tiny stick-slip motions caused by friction between the surface and the tip of the whisker.

"One of the most striking things we found both in the experiments and the theory was the thousand-fold amplification of tiny force signals perceived by the tip of the whisker to that received by the neurons at the whiskers base. Suddenly we realised that the whisker is acting like an amplifier, taking micro-scale stick-slip events and rapidly turning them into clean pulses that can be picked up and processed by the brain," said Professor Alan Champneys from the University of Bristol, co-lead of the modelling work with colleague, Dr Robert Szalai. Dr Thibaut Putelat carried out the detailed numerical modelling.

The research Conveyance of texture signals along a rat whisker, published in the journal Scientific Reports from the publisher Nature, reveals the tapering of the whisker has the effect of amplifying tiny high-frequency motions into appreciable pulse-like changes in forces and movement at the whisker follicle. In turn, the nerve cells in the follicle sense these changes and transmit them to the brain.

"It is almost as if the morphology of the whisker is designed to convey these friction-induced signals as "AC" waves on top of the "DC" motion of the whisker that conveys the information on surface proximity and hardness.

"These AC waves are too small and too rapid to be perceived by the human eye. However, in approaching this problem in a multidisciplinary fashion, we have been able to reveal these waves with clarity for the first time," said Professor Champneys.

"The findings have implications for human touch too, where the morphology of finger-print ridges is more complex, but might similarly distinguish between AC and DC signals as our brain tries to disentangle multiple information streams about what we are feeling," said Dr Maysam Oladazimi, who carried out the experiments as part of his PhD.

The findings could have far-reaching benefits including how textures could be designed to provide optimal cues for the visually impaired, for human safety operation in low light environments, or for immersive artistic installations.

"This research opens several avenues for future work. As neuroscientists, we are interested in developing a more detailed understanding of neural signalling pathways in texture discrimination, while our colleagues in Bristol are keen to explore implications for the design of future robotic sensing systems," said Professor Cornelius Schwarz, who led the experiments at the University of Tuebingen.

Professor Champneys said the research was of particular value to haptic-sensing in the field of robotics, where robots literally feel their environment and is the focus of much current research, especially for robots that need to act autonomously in the dark, such as in search and rescue missions. Professor Nathan Lepora and colleagues at the Bristol Robotics Laboratory are pioneers in this field.

"This transnational interdisciplinary collaboration between experimentalists and mathematical modellers was exciting. The results from the computer models and from the laboratory experiments went hand in hand - it was only through a combination of the two that we were able to make our breakthrough," said Professor Champneys.

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Paper:

Conveyance of texture signals along a rat whisker, by Oladazimi, M; Putelat, T; Szalai, R; Noda, K; Shimoyama, I; Champneys, A & Schwarz, C; published in Scientific Reports. 11, 13570 (2021). https://doi.org/10.1038/s41598-021-92770-3

 OF MICE AND MEN

Combining plant-based diet and a healthy microbiome may protect against multiple sclerosis

Metabolism of isoflavone by gut bacteria protects mice from MS-like inflammation

UNIVERSITY OF IOWA HEALTH CARE

Research News

A new University of Iowa study suggests that metabolism of plant-based dietary substances by specific gut bacteria, which are lacking in patients with multiple sclerosis (MS), may provide protection against the disease.

The study led by Ashutosh Mangalam, PhD, UI associate professor of pathology, shows that a diet rich in isoflavone, a phytoestrogen or plant-based compound that resembles estrogen, protects against multiple sclerosis-like symptoms in a mouse model of the disease. Importantly, the isoflavone diet was only protective when the mice had gut microbes capable of breaking down the isoflavones. The findings were published July 9 in Science Advances.

"Interestingly, previous human studies have demonstrated that patients with multiple sclerosis lack these bacteria compared to individuals without MS," Mangalam says. "Our new study provides evidence that the combination of dietary isoflavones and these isoflavone metabolizing gut bacteria may serve as a potential treatment for MS."

Isoflavones are found in soybeans, peanuts, chickpeas and other legumes. The study also found that mice fed the isoflavone diet have a microbiome that is similar to the microbiome found in healthy people and includes the bacteria which can metabolize isoflavones. Conversely, a diet lacking isoflavones promotes a microbiome in mice which is similar to one observed in patients with MS and lacks beneficial bacteria that can metabolize isoflavone.

Multiple sclerosis is an autoimmune disease of the brain and spinal cord where the immune system attacks the protective coating surrounding nerve fibers. The symptoms of this disease include muscles weakness, balance issues, and problems with vision and thinking. While there are treatments that slow down the disease, there is currently no cure for MS.

Although the exact cause of MS is unknown, a complex interaction between genetic and environmental factors are thought to initiate the disease. Recently, the gut microbiome--the trillions of gut bacteria the live inside human intestines--has emerged as a potential environmental factor that contributes to MS. In prior work, Mangalam and colleagues demonstrated that there are significant differences between the gut microbes of patients with MS and people without MS. Specifically, patients with MS lacked bacteria that are able to metabolize isoflavones. Although role of gut microbiome in human diseases such as MS is being appreciated, the mechanism through which these gut bacteria might influence the disease is poorly understood.

In the current study, Mangalam's team, including first author Samantha Jensen, a UI graduate student in immunology, found that the bacteria that are lacking in patients with MS are able to suppress inflammation in a mouse model of MS. The team compared the effects of an isoflavone diet and an isoflavone-free diet on disease in the mouse model of MS. They found that the isoflavone diet led to disease protection. However, when the team placed the mice on the isoflavone diet but removed the isoflavone-metabolizing gut bacteria, the isoflavone diet was no longer able to protect against MS-like symptoms. When the bacteria were reintroduced, the protective effect of the isoflavone diet was restored. Furthermore, the team was able to show that a specific isoflavone metabolite called equol, which is produced by the gut bacteria from isoflavone, is also able to provide protection against disease.

"This study suggests that an isoflavone diet may be protective so long as the isoflavone metabolizing gut bacteria are present in the intestines," say Mangalam, who also is a member of the Iowa Neuroscience institute and Holden Comprehensive Cancer Center.

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The research was supported in part by the National Multiple Sclerosis Society, the National Institute of Allergy and Infectious Diseases, the National Institute of Environmental Health Sciences, and the Roy J. Carver Charitable Trust.

In addition to Mangalam and Jensen, the team included UI scientists Shailesh Shahi and Stephanie Peterson; Katherine Gibson-Corley at Vanderbilt University; Nicole Cady at the University of Michigan; and Arnav Gupta at the KK Birla in Goa.

 

Empathy may drive rats and other mammals to help friends over strangers

A new study identifies the brain regions involved in rats' tendency to help members of their own social group over strangers, with findings that may help scientists better understand similar social biases in humans

ELIFE

Research News

 

IMAGE: NEW FINDINGS REVEAL THAT RATS FEEL EMPATHY FOR OTHER RATS, BUT REFRAIN FROM HELPING THOSE OUTSIDE THEIR SOCIAL GROUP. view more 

CREDIT: INBAL BEN-AMI BARTAL (CC BY 4.0)

Rescuing a member of their own social group, but not a stranger, triggers motivational and social reward centres in rats' brains, suggests a report published today in eLife.

The study provides the first description of similar brain activity in both rats and humans underlying this socially biased behaviour. The findings add to our understanding of social biases and could help with developing ways to promote cooperation outside of an individual's social group.

"Humans, as well as many other creatures, are biased toward helping other members of their social groups over individuals they view as outsiders, and this can have a negative impact in diverse societies where different groups need to cooperate in order to thrive," says first author Inbal Ben-Ami Bartal, a faculty member at the Sagol School of Neuroscience and the Psychology Department at Tel-Aviv University, Israel. "Understanding the brain mechanisms underlying these biases is essential to finding ways to eliminate them."

To explore this further, Bartal and a multinational team of colleagues placed rats in a situation where either a cage mate of the same type of rat, or a different type of rat they had never met, was trapped. In the experiments, most rats learned to free their cage mate, but few rescued the stranger.

The team then examined the brain activity associated with these behaviours to understand why the rats were biased towards helping their cage mates. They found that some regions of the brain are activated in response to the distress of either a cage mate or an unfamiliar rat, meaning that rats sense the distress of another animal whether or not they know them. But additional brain regions associated with reward seeking and positive social experiences were turned on only when a cage mate was in distress. "This brain activity in the rats that helped their fellow group members suggests an empathetic response to their distress," Bartal says.

Previous studies in humans have also suggested that empathy towards fellow group members drives the desire to help them but not strangers. The current findings suggest that similar brain activity may drive these social biases in rats and potentially other mammals.

"We've provided the first evidence for a common biological mechanism driving empathic helping behaviours in humans and rats in response to the distress of friends," concludes senior author Daniela Kaufer, Professor at the Department of Integrative Biology and the Helen Wills Neuroscience Institute at the University of California, Berkeley, US. "Our results lay the groundwork for future studies to better understand the brain activity involved and why it causes us to choose helping some people over others."

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About eLife

eLife is a non-profit organisation created by funders and led by researchers. Our mission is to accelerate discovery by operating a platform for research communication that encourages and recognises the most responsible behaviours. We aim to publish work of the highest standards and importance in all areas of biology and medicine, including Neuroscience, while exploring creative new ways to improve how research is assessed and published. eLife receives financial support and strategic guidance from the Howard Hughes Medical Institute, the Knut and Alice Wallenberg Foundation, the Max Planck Society and Wellcome. Learn more at https://elifesciences.org/about.

To read the latest Neuroscience research published in eLife, visit https://elifesciences.org/subjects/neuroscience.

 

Are silver nanoparticles a silver bullet against microbes?

Leanne Gilbertson's group studies the mechanisms behind bacterial resistance to silver nanoparticles to determine if their ubiquitous use is a solution to the antimicrobial resistance challenge or if it is perhaps fueling the fire

UNIVERSITY OF PITTSBURGH

Research News

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IMAGE: A DEPICTION OF HYPER-MOTILE E.COLI, A STRAIN OF BACTERIA FOUND TO RESIST SILVER NANOPARTICLES' ANTIMICROBIAL PROPERTIES AFTER REPEATED EXPOSURE. view more 

CREDIT: LISA STABRYLA/UNIVERSITY OF PITTSBURGH.

Antimicrobials are used to kill or slow the growth of bacteria, viruses and other microorganisms. They can be in the form of antibiotics, used to treat bodily infections, or as an additive or coating on commercial products used to keep germs at bay. These life-saving tools are essential to preventing and treating infections in humans, animals and plants, but they also pose a global threat to public health when microorganisms develop resistance to them, a concept known as antimicrobial resistance.

One of the main drivers of antimicrobial resistance is the misuse and overuse of antimicrobial agents, which includes silver nanoparticles, an advanced material with well-documented antimicrobial properties. It is increasingly used in commercial products that boast enhanced germ-killing performance - it has been woven into textiles, coated onto toothbrushes, and even mixed into cosmetics as a preservative.

The Gilbertson Group at the University of Pittsburgh Swanson School of Engineering used laboratory strains of E.coli to better understand bacterial resistance to silver nanoparticles and attempt to get ahead of the potential misuse of this material. The team recently published their results in Nature Nanotechnology.

"Bacterial resistance to silver nanoparticles is understudied, so our group looked at the mechanisms behind this event," said Lisa Stabryla, lead author on the paper and a recent civil and environmental PhD graduate at Pitt. "This is a promising innovation to add to our arsenal of antimicrobials, but we need to consciously study it and perhaps regulate its use to avoid decreased efficacy like we've seen with some common antibiotics."

Stabryla exposed E.coli to 20 consecutive days of silver nanoparticles and monitored bacterial growth over time. Nanoparticles are roughly 50 times smaller than a bacterium.

"In the beginning, bacteria could only survive at low concentrations of silver nanoparticles, but as the experiment continued, we found that they could survive at higher doses," Stabryla noted. "Interestingly, we found that bacteria developed resistance to the silver nanoparticles but not their released silver ions alone."

The group sequenced the genome of the E.coli that had been exposed to silver nanoparticles and found a mutation in a gene that corresponds to an efflux pump that pushes heavy metal ions out of the cell.

"It is possible that some form of silver is getting into the cell, and when it arrives, the cell mutates to quickly pump it out," she added. "More work is needed to determine if researchers can perhaps overcome this mechanism of resistance through particle design."

The group then studied two different types of E.coli: a hyper-motile strain that swims through its environment more quickly than normally motile bacteria and a non-motile strain that does not have physical means for moving around. They found that only the hyper-motile strain developed resistance.

"This finding could suggest that silver nanoparticles may be a good option to target certain types of bacteria, particularly non-motile strains," Stabryla said.

In the end, bacteria will still find a way to evolve and evade antimicrobials. The hope is that an understanding of the mechanisms that lead to this evolution and a mindful use of new antimicrobials will lessen the impact of antimicrobial resistance.

"We are the first to look at bacterial motility effects on the ability to develop resistance to silver nanoparticles," said Leanne Gilbertson, assistant professor of civil and environmental engineering at Pitt. "The observed difference is really interesting and merits further investigation to understand it and how to link the genetic response - the efflux pump regulation - to the bacteria's ability to move in the system.

"The results are promising for being able to tune particle properties for a desired response, such as high efficacy while avoiding resistance."

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Mosquito-resistant clothing prevents bites in trials

NORTH CAROLINA STATE UNIVERSITY

Research News

North Carolina State University researchers have created insecticide-free, mosquito-resistant clothing using textile materials they confirmed to be bite-proof in experiments with live mosquitoes. They developed the materials using a computational model of their own design, which describes the biting behavior of Aedes aegypti, the mosquito that carries viruses that cause human diseases like Zika, Dengue fever and yellow fever.

Ultimately, the researchers reported in the journal Insects that they were able to prevent 100 percent of bites when a volunteer wore their clothing - a base layer undergarment and a combat shirt initially designed for the military - in a cage with 200 live, disease-free mosquitoes. Vector Textiles, an NC State startup company, has licensed the related patent rights and intends to make clothing for commercial sale in the United States.

The researchers think their computational model could be used more widely to develop clothing to reduce transmission of diseases.

"The fabric is proven to work - that's the great thing we discovered," said study co-author Andre West, associate professor of fashion and textile design at NC State and director of Zeis Textiles Extension for Economic Development. "To me, that's revolutionary. We found we can prevent the mosquito from pushing through the fabric, while others were thick enough to prevent it from reaching the skin."

To develop the computational model to design textile materials that could prevent A. aegypti bites, researchers investigated the dimensions of the head, antenna and mouth of A. aegypti, and the mechanics of how it bites. Then, they used the model to predict textile materials that would prevent bites, depending on their thickness and pore size. Researchers said they believe the materials could be effective against other mosquito species in addition to A. aegypti because of similarities in biology and biting behavior.

"There are different uses for clothing," said the study's first author Kun Luan, postdoctoral research scholar of forest biomaterials at NC State. "The idea is to have a model that will cover all possible garments that a person would ever want."

To test the accuracy of their model, the researchers tested the materials predicted to be bite-proof. In experiments with live, disease-free mosquitoes, the researchers surrounded a blood reservoir with plastic materials made according to parameters predicted by the model. They then counted how many mosquitoes became engorged with blood.

One material they initially tested was very thin - less than one millimeter thick - but had a very small pore size to prevent the mosquito from sticking its mouth parts, or proboscis, through the material. Another material had a medium pore size to prevent the mosquito from inserting its head through the textile far enough to reach the skin; and a third material had larger pores, but was sufficiently thick that the mosquito's mouth still couldn't reach the skin.

In a subsequent test, the researchers chose a series of knitted and woven fabrics that met the bite-proof parameters determined by the model, and validated they worked in experiments using both the blood reservoir and human volunteers. The researchers tested the number of bites received by volunteers when study participants inserted an arm covered by a protective sleeve into a mosquito cage. The researchers also compared the fabrics' ability to prevent bites and repel mosquitoes to fabrics treated with an insecticide.

From what they learned in early experiments, researchers developed the bite-resistant, form-fitting undergarment made with a thin material, as well as a long-sleeved shirt, which was initially envisioned as a combat shirt for the military.

When a volunteer wore the garments sitting for 10 minutes and standing for 10 minutes in a walk-in cage with 200 hungry mosquitos, the volunteer found the combat shirt was 100 percent effective at preventing bites. In the first trial testing the base layer, the volunteer received bites on the back and shoulders - seven bites for 200 mosquitoes. The researchers attributed the bites to the fabric stretching and deforming, so they doubled the material layer around the shoulders, and were ultimately able to prevent 100 percent of bites. They also tested the clothing for comfort, and to see how well it trapped heat and released moisture.

"The final garments that were produced were 100 percent bite-resistant," said Michael Roe, William Neal Reynolds Distinguished Professor of Entomology at NC State. "Everyday clothing you wear in the summer is not bite-resistant to mosquitoes. Our work has shown that it doesn't have to be that way. Clothes that you wear every day can be made bite-resistant. Ultimately, the idea is to have a model that will cover all possible garments that person would ever want - both for the military as well as for private use."

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The study, "Mosquito-textile physics: A mathematical roadmap to insecticide-free, bite-proof clothing for everyday life," was published online July X, 2021, in the journal Insects. It was authored by Luan, Roe, West, Charles Apperson, Marian McCord, Emiel DenHartog, Quan Shi, Nicholas Travanty, Robert Mitchell, Grayson Cave, John Strider and Youngxin Wang from NC State University and Isa Bettermann, Florian Neumann and Tobias Beck from Aachen University, Germany. The study was supported by the National Science Foundation, the Department of Defense Deployed War Fighter Program, Natick Contracting Division of the U.S. Department of Defense, the Chancellor's Innovation Fund at NC State, the Southeast Center for Agricultural Health and Injury Prevention, PILOTS and the NC Agriculture Research Experiment Station.

Note to editors: The abstract follows.

"Mosquito-textile physics: A mathematical roadmap to insecticide-free, bite-proof clothing for everyday life"

Authors: Kun Luan, Andre J. West, Marian G. McCord, Emiel DenHartog, Quan Shi, Isa Bettermann, Jiayin Li, Nicholas V. Travanty, Robert D. Mitchell III, Grayson L. Cave, John B. Strider, Yongxin Wang, Florian Neumann, Tobias Beck, Charles S. Apperson and R. Michael Roe.

Published online in Insects on July 13, 2021.

DOI: 10.3390/insects12070636

Abstract: Garments treated with chemical insecticides are commonly used to prevent mosquito bites. Resistance to insecticides, however, is threatening the efficacy of this technology, and people are increasingly concerned about the potential health impacts of wearing insecticide-treated clothing. Here, we report a mathematical model for fabric barriers that resist bites from

Aedes aegypti mosquitoes based on textile physical structure and no insecticides. The model was derived from mosquito morphometrics and analysis of mosquito biting behavior. Precision polypropylene plates were first used to simulate woven and knitted fabrics for model validation.

Then based on model predictions, prototype knitted textiles and garments were developed that prevented mosquito biting and were tested for comfort. Our predictive model can be used to develop additional textiles in the future for garments that are highly bite-resistant to mosquitoes.

Disclaimer: AAAS and

 

Study: Racial/ethnic and language inequities in ways patients obtain COVID-19 testing

UNIVERSITY OF MINNESOTA

Research News

The COVID-19 pandemic caused an unprecedented disruption to health care delivery, with resources shifted toward telehealth services and mass viral testing. While early studies in the pandemic highlighted differences in health care utilization among patients with commercial insurance, data from publicly insured or uninsured "safety-net" patient populations continue to emerge.

A recent study from researchers at the University of Minnesota and Hennepin Healthcare Research Institute (HHRI) is among the first to examine how different socio-demographic groups used telehealth, outpatient (i.e., clinic), emergency department and inpatient (i.e., hospital) care to test for SARS-CoV-2, the virus that causes COVID-19. Their findings were recently published in JAMA Network Open.

The study was led by U of M School of Public Health graduate student Rohan Khazanchi. Along with others from Hennepin Healthcare and HHRI, researchers included Medical School Assistant Professor Tyler Winkelman, who is also with the U of M Robina Institute of Criminal Law and Criminal Justice, and HHRI Data Scientist Peter Bodurtha. The team analyzed anonymous electronic health record data for people with symptoms of viral illness who received SARS-CoV-2 testing at Hennepin Healthcare, a large safety-net health system in Minneapolis.

The study found that:

• Patients who initiated testing via telehealth were disproportionately white and English-speaking, whereas patients who initiated testing through the emergency department were disproportionately Black, Native American, non-English-speaking and had one or more pre-existing conditions.
• Testing initiated through telehealth and outpatient encounters was associated with lower rates of subsequent inpatient and intensive care unit care than testing initiated in more care-intensive settings, such as emergency departments.

"Inequities by race, ethnicity and language in where people seek SARS-CoV-2 testing may point to several structural root causes, including barriers to timely testing access, delays in care seeking, difficulty accessing telehealth services, and higher rates of pre-existing conditions among patients who require higher levels of care," said Khazanchi.

The researchers also added that the inequities could be partially explained by clinician and clinic variations in telehealth use.

"Without structural reforms, rapid implementation of telehealth and other new services may exacerbate inequities in access to care, particularly if these investments come at the expense of other care sites," said Bodurtha.

The authors said that as investigators explore the effects of the COVID-19 pandemic on health use and patient outcomes, future research should continue to examine how and why the health care use of safety-net patients differs from commercially insured individuals to inform equity-oriented interventions.

The study was supported by the National Institutes of Health's National Center for Advancing Translational Sciences (#UL1TR002494).