Zika virus has triggered large outbreaks in human populations, in some cases causing congenital deformities, fetal loss, or neurological problems in adults. While the yellow fever mosquito Aedes aegypti is considered the primary vector of Zika virus, the Asian tiger mosquito Aedes albopictus has been shown experimentally to transmit the virus and was involved in several transmissions of the virus in France in 2019. Originating from Southeast Asia, Ae. aegypti is an aggressive biter that has invaded the world and is now present on all inhabited continents, including temperate Europe, due to its ability to endure harsh winter conditions. As the second most important vector of human viral pathogens, Ae. albopictus is displacing Ae. aegypti populations due to competitive advantages. But it is not known if Ae. albopictus could trigger large-scale Zika virus epidemics.

To address this question, the researchers exposed Ae. albopictus to Zika virus and assessed infection rates in experiments, modeled the dynamics of Zika virus infection within individual humans, and used epidemiological simulations. The highest risk of transmission occurred during the pre-symptomatic stage of the disease. At this dose, mosquito infection probability was estimated to be 20%, and 21 days were required to reach median systemic infection rates. Despite these unfavorable characteristics for transmission, Ae. albopictus was still able to trigger large outbreaks in a simulated environment in the presence of sufficiently high mosquito densities and biting rates. According to the authors, active surveillance and eradication programs should be implemented in territories occupied by Ae. albopictus to maintain the low risk of Zika virus outbreaks.

The authors conclude, “The complementary combination of dose-dependent experimental infection, modeling of intra-human viremia dynamics, and in silico epidemiological simulations confirms the low epidemic potential of Aedes albopictus for Zika virus.”

Story Source:

Materials provided by PLOS. Note: Content may be edited for style and length.

In response to accounts of potential allergic reactions in some people following COVID-19 vaccination in the United Kingdom, that country’s medical regulatory agency advised that individuals with a history of anaphylaxis to a medicine or food should avoid COVID-19 vaccination. After closer review of the data related to allergic reactions, however, the FDA recommended that the vaccines be withheld only from individuals with a history of severe allergic reactions to any component of the COVID-19 vaccine, and the Centers for Disease Control and Prevention advised that all patients be observed for 15 minutes post-vaccination by staff who can identify and manage such reactions. The U.S. agencies do not recommend that people with food or medication allergies avoid vaccination.

To provide insights from allergists’ perspectives, Aleena Banerji, MD, clinical director of the Allergy and Clinical Immunology Unit at MGH and associate professor at Harvard Medical School, and her colleagues have summarized what’s currently known about allergic reactions to vaccines like those developed against COVID-19, and they have proposed detailed advice so that individuals with different allergy histories can safely receive their first COVID-19 vaccine. They also outline steps on safely receiving the second dose in individuals who develop a reaction to their first dose of COVID-19 vaccine.

“As allergists, we want to encourage vaccination by reassuring the public that both FDA-approved COVID-19 vaccines are safe. Our guidelines are built upon the recommendations of U.S. regulatory agencies and provide clear steps to the medical community on how to safely administer both doses of the vaccine in individuals with allergic histories,” says Banerji.

The experts note that allergic reactions to vaccines are rare, with a rate of about 1.3 per 1 million people. They also determined that the Pfizer-BioNTech and Moderna COVID-19 vaccine allergic reactions will have a similarly low rate of occurrence. They stress that vaccine clinics will be monitoring all patients for 15 to 30 minutes and can manage any allergic reactions that occur. Banerji and her co-authors recommend that individuals with a history of anaphylaxis to an injectable drug or vaccine containing polyethylene glycol or polysorbate speak with their allergists before being vaccinated. They stress that patients with severe allergies to foods, oral drugs, latex, or venom can safely receive the COVID-19 vaccines.

Co-senior authors of the review are MGH’s Kimberly G. Blumenthal, MD, MSc, and Brigham and Women’s Elizabeth Phillips, MD. Other co-authors include MGH’s Paige G. Wickner, MD, Rebecca Saff, MD, PhD, Lacey B. Robinson, MD, MPH, Aidan A. Long, MD, Anna R. Wolfson, MD, and David A. Khan, MD; Cosby A. Stone Jr., MD, MPH, of Vanderbilt University Medical Center; and Paul Williams, MD, of the University of Washington School of Medicine.

Story Source:

Materials provided by Massachusetts General Hospital. Note: Content may be edited for style and length.

After looking at social media posts, parents of young children were better able to recall safety messages such as how to put a baby safely to sleep when the images in the posts aligned with the messages in the text, the researchers found.

The study appears in the Journal of Health Communication.

“Many times, scientists and safety experts aren’t involved in decisions about social media for health agencies and other organizations, and we end up seeing images that have nothing to do with the safety message or, worse, images that contradict the guidance,” said lead author Liz Klein, an associate professor of public health at The Ohio State University.

Take the safe sleep example, for instance. The researchers found posts that advocated a bumper-free crib for baby but used an image of an infant in a crib with bumpers. They saw posts about preventing head injury with bike helmets illustrated by pictures of kids without bike helmets.

“In this study, we were trying to understand how much those mismatches matter — do people understand the message even if the picture isn’t right? Does the picture really matter?” Klein said.

Their answers came from research using eye-tracking technology to gauge the attention young parents paid to various posts, and subsequent tests to see what they recalled about the safety messages.

When the 150 parents in the study were shown a trio of posts with matched imagery and text and three other posts with mismatched visual and written messages, they spent far longer on the matched posts — 5.3 seconds, compared to the 3.3 seconds their eyes lingered on the mismatched posts.

Further, the matched messages appeared to make a difference in understanding and recall of safety messages. After accounting for differences in health literacy and social media use among participants, the researchers found that each second of viewing time on matched posts was associated with a 2.8% increase in a safety knowledge score.

“With nearly 70% of adults reporting use of social media, and many parents using social media and other internet sources to keep current on injury prevention strategies, social media is a great opportunity to broadcast safety and injury prevention messages,” said study co-author Lara McKenzie, a principal investigator in the Center for Injury Research and Policy at Nationwide Children’s Hospital in Columbus.

“As more health organizations and public health agencies use social media to share health information with the public, the findings of our study underscore the need to ensure that the imagery and text in social media posts are aligned.”

Klein said she understands that those managing social media accounts may be drawn to images that are the most attention-grabbing. But when it comes to health and safety, this study suggests that making sure the image and the text are sending the same message is more important.

“If you want people to put their medicine up and out of reach of children, kids to wear their bike helmets or new parents to remember that babies should always go to sleep on their backs, alone and in a crib — that’s where matching matters. Maybe save the eye-grabbing stuff and the humorous posts for different purposes.”

Klein said the findings in this study likely extend beyond child safety messaging to any number of health and safety campaigns, but that there’s more work to be done to understand how best to harness the power of social media for different types of public health communication.

“We need to pay more attention to how we communicate with the people we’re trying to influence with health and safety guidance. All of us can do a better job of thinking about how we use our social media accounts to contribute to better public health,” she said.

Story Source:

Materials provided by Ohio State University. Original written by Misti Crane. Note: Content may be edited for style and length.

The article, “The neural mechanisms underlying processing speed deficits in individuals who have sustained a spinal cord injury: A pilot study”  was published online on September 25, 2020 by Brain Topography. The authors are scientists with expertise in research in cognitive rehabilitation and SCI rehabilitation: Glenn Wylie, DPhil, Nancy D. Chiaravalloti, PhD, Erica Weber, PhD, Helen Genova, PhD, and Trevor Dyson-Hudson, MD, from Kessler Foundation, and Jill M. Wecht, EdD, from the James J. Peters VA Medical Center.

Individuals with chronic SCI have an increased risk for cognitive deficits that resemble the deficits associated with the aging process, giving rise to the theory of “accelerated cognitive aging.” As reported previously by this team, the deficits affect processing speed, new learning and memory, and verbal fluency, which are the domains affected during aging. This study is the first to examine the neural mechanisms of higher order cognitive tasks of individuals with SCI. The focus was on processing speed, which is known to be affected by SCI and aging, and is integral to cognitive function and everyday life activities.

The 30 participants were participants of a larger study who underwent optional neuroimaging studies at the Rocco Ortenzio Neuroimaging Center at Kessler Foundation — 10 individuals with cervical SCI, 10 age-matched controls, and 10 healthy older individuals. In addition to traditional neuropsychological testing methods, processing speed was tested in the scanner, using timed letter comparison tasks during functional magnetic resonance imaging (fMRI). This study was the first to use the modified letter comparison test.

Significant differences in brain activation were found between the SCI group and the age-matched control group, but the SCI and older groups had similar patterns, including activation of the hippocampal, frontal and parietal areas. “This suggests that individuals with SCI are compensating for deficits in processing speed by relying on the areas of the brain involved in executive control and memory,” noted Dr. Chiaravalloti, “which supports the theory of accelerated brain aging after SCI.”

Despite the limitations of sample size and level of injury, the study is an important contribution to our understanding of the impact of SCI on cognition, according to Dr. Wylie, director of the Ortenzio Center. “Our ability to observe brain activation while the individual performs specific cognitive tasks provides new information on the mechanisms that underlie the cognitive deficits that we now know affect a substantial proportion of the SCI population,” Dr. Wylie said. “Developing treatments targeted to these deficits depends on our pursuit of this line of research, which may benefit other populations affected by delayed processing speed.”

Story Source:

Materials provided by Kessler Foundation. Note: Content may be edited for style and length.

The structure of the lungs exposes them to viruses and bacteria from both the air and the blood. Macrophages are immune cells that, among other things, protect the lungs from such attacks. But under certain conditions, lung macrophages can also contribute to severe lung diseases, such as chronic obstructive pulmonary disease (COPD) and COVID-19.

To date, research on the development of human lung macrophages has been limited.

Macrophages can have different origins and develop, among other things, from white blood cells, monocytes, that are divided into different genetically determined main types. In humans, two of these are “classical” CD14+ monocytes and “non-classical” CD16+ monocytes.

In a new study at Karolinska Institutet, researchers have used a model to study the development of lung macrophages directly in a living lung. This has been combined with a method to study gene activity in individual cells, RNA sequencing, and thereby discovered how blood monocytes become human lung macrophages.

“In our study, we show that classical monocytes migrate into airways and lung tissue and are converted into macrophages that protect the health and function of the lungs. We have also identified a special kind of monocyte, HLA-DRhi, which is an intermediate immune cell between a blood monocyte and an airway macrophage. These HLA-DRhi monocytes can leave the blood circulation and migrate into the lung tissue,” says Tim Willinger, Associate Professor at the Department of Medicine, Huddinge, Karolinska Institutet, who led the study.

The non-classical monocytes, however, develop into macrophages in the many blood vessels of the lungs and do not migrate into the lung tissue.

“Certain macrophages in the lungs probably have a connection to a number of severe lung diseases. In respiratory infections, for example, monocytes in the lungs develop into macrophages, which combat viruses and bacteria. But a certain type of macrophage may also contribute to severe inflammation and infections,” says the study’s first author Elza Evren, a doctoral student in Tim Willinger’s research team.

In an infection with the novel coronavirus, SARS-COV-2, which causes COVID-19, researchers believe that protective, anti-inflammatory macrophages are replaced by pro-inflammatory lung macrophages from blood monocytes.

“The existence of these blood monocyte-derived macrophages has been shown in other studies to correlate with how severely ill a person becomes in COVID-19 and how extensive the damage to the lungs is. Patients with severe COVID-19 also have fewer HLA-DRhi monocytes in their blood, probably because they move away from the blood into the lungs. Given their important role in rapid inflammatory responses, our results indicate that future treatments should focus on inflammatory macrophages and monocytes to reduce lung damage and mortality from severe COVID-19,” says Tim Willinger.

The research is financed by the Swedish Research Council, Karolinska Institutet, Centre for Innovative Medicine (CIMED)/Region Stockholm, the Swedish Heart-Lung Foundation, and the Swedish Cancer Foundation. There are no reported conflicts of interest.

Story Source:

Materials provided by Karolinska Institutet. Note: Content may be edited for style and length.