pathogen Archives - Amazing Health Advances

New Method Developed to Assess the Effectiveness of Facemasks in Obstructing Droplets

AHA Publisher — Wed, 01 Jul 2020 07:00:46 +0000

Florida Atlantic University via News-Medical Net – Currently, there are no specific guidelines on the most effective materials and designs for facemasks to minimize the spread of droplets from coughs or sneezes to mitigate the transmission of COVID-19. While there have been prior studies on how medical-grade masks perform, data on cloth-based coverings used by the vast majority of the general public are sparse. Research from Florida Atlantic University’s College of Engineering and Computer Science, just published in the journal Physics of Fluids, demonstrates through visualization of emulated coughs and sneezes, a method to assess the effectiveness of facemasks in obstructing droplets. The rationale behind the recommendation for using masks or other face coverings is to reduce the risk of cross-infection via the transmission of respiratory droplets from infected to healthy individuals. Researchers employed flow visualization in a laboratory setting using a laser light sheet and a mixture of distilled water and glycerin to generate the synthetic fog that made up the content of a cough-jet. They visualized droplets expelled from a mannequin’s mouth while simulating coughing and sneezing. They tested masks that are readily available to the general public, which do not draw away from the supply of medical-grade masks and respirators for healthcare workers. They tested a single-layer bandana-style covering, a homemade mask that was stitched using two-layers of cotton quilting fabric consisting of 70 threads per inch, and a non-sterile cone-style mask that is available in most pharmacies. By placing these various masks on the mannequin, they were able to map out the paths of droplets and demonstrate how differently they perform. Results showed that loosely folded facemasks and bandana-style coverings provide minimal stopping-capability for the smallest aerosolized respiratory droplets. Well-fitted homemade masks with multiple layers of quilting fabric, and off-the-shelf cone style masks, proved to be the most effective in reducing droplet dispersal. These masks were able to curtail the speed and range of the respiratory jets significantly, albeit with some leakage through the mask material and from small gaps along the edges. Importantly, uncovered emulated coughs were able to travel noticeably farther than the currently recommended 6-foot distancing guideline. Without a mask, droplets traveled more than 8 feet; with a bandana, they traveled 3 feet, 7 inches; with a folded cotton handkerchief, they traveled 1 foot, 3 inches; with the stitched quilted cotton mask, they traveled 2.5 inches; and with the cone-style mask, droplets traveled about 8 inches. “In addition to providing an initial indication of the effectiveness of protective equipment, the visuals used in our study can help convey to the general public the rationale behind social-distancing guidelines and recommendations for using facemasks,” said Siddhartha Verma, Ph.D., lead author and an assistant professor who co-authored the paper with Manhar Dhanak, Ph.D., department chair, professor, and director of SeaTech; and John Frakenfeld, technical paraprofessional, all within FAU’s Department of Ocean and Mechanical Engineering. “Promoting widespread awareness of effective preventive measures is crucial at this time as we are observing significant spikes in cases of COVID-19 infections in many states, especially Florida.” When the mannequin was not fitted with a mask, they projected droplets much farther than the 6-foot distancing guidelines currently recommended by the United States Centers for Disease Control and Prevention. The researchers observed droplets traveling up to 12 feet within approximately 50 seconds. Moreover, the tracer droplets remained suspended midair for up to three minutes in the quiescent environment. These observations, in combination with other recent studies, suggest that current social-distancing guidelines may need to be updated to account for aerosol-based transmission of pathogens. “We found that although the unobstructed turbulent jets were observed to travel up to 12 feet, a large majority of the ejected droplets fell to the ground by this point,” said Dhanak. “Importantly, both the number and concentration of the droplets will decrease with increasing distance, which is the fundamental rationale behind social-distancing.” The pathogen responsible for COVID-19 is found primarily in respiratory droplets that are expelled by infected individuals during coughing, sneezing, or even talking and breathing. Apart from COVID-19, respiratory droplets also are the primary means of transmission for various other viral and bacterial illnesses, such as the common cold, influenza, tuberculosis, SARS (Severe Acute Respiratory Syndrome), and MERS (Middle East Respiratory Syndrome), to name a few. These pathogens are enveloped within respiratory droplets, which may land on healthy individuals and result in direct transmission, or on inanimate objects, which can lead to infection when a healthy individual comes in contact with them. “Our researchers have demonstrated how masks are able to significantly curtail the speed and range of the respiratory droplets and jets. Moreover, they have uncovered how emulated coughs can travel noticeably farther than the currently recommended six-foot distancing guideline,” Stella Batalama, Ph.D., Dean, Florida Atlantic University College of Engineering and Computer Science “Their research outlines the procedure for setting up simple visualization experiments using easily available materials, which may help healthcare professionals, medical researchers, and manufacturers in assessing the effectiveness of face masks and other personal protective equipment qualitatively.” To read the original article click here.

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The Parkinson’s Disease Gut Has an Overabundance of Opportunistic Pathogens

AHA Publisher — Mon, 29 Jun 2020 07:00:35 +0000

University of Alabama at Birmingham via Newswise – Parkinson’s disease is a common, progressive and debilitating neurodegenerative disease. It currently cannot be prevented or cured. In 2003, Heiko Braak proposed that non-inherited forms of PD are caused by a pathogen in the gut. He hypothesized that the pathogen could pass through the intestinal mucosal barrier and spread to the brain through the nervous system. Up to now, there has been no evidence of a specific pathogen that may trigger PD. Now Haydeh Payami, Ph.D., professor of neurology at the University of Alabama at Birmingham, and colleagues report for the first time a significant overabundance of a cluster of opportunistic pathogens in the guts of persons with PD, compared to control subjects. “The exciting question is whether these are Braak’s pathogens capable of triggering PD, or are they irrelevant to PD but able to penetrate the gut and grow, because the gut lining is compromised in PD,” Payami said. “We emphasize that no claims can be made on function based solely on association. The identity of these microorganisms will enable experimental studies to determine whether and how they play a role in PD.” Payami and colleagues at UAB, Emory University, Albany Medical College and the University of Washington were able to identify these microorganisms because they performed the largest microbiome-wide association study of persons with PD and controls to date. Many previous studies have found altered gut microbiomes in persons with PD but did not detect an increase in opportunistic pathogens. Opportunistic pathogens are often harmless, but they can grow and cause infections if the immune system is compromised or if they penetrate into sterile sites of the body. “We suspect the reason we were able to detect these microorganisms is that they are rare and we had a much larger sample size and power than prior studies,” Payami said. Her researchers re-analyzed their 2017 study that had 197 cases and 130 controls, using a more advanced bioinformatics pipeline. They also analyzed a new, independent dataset with 323 cases of PD and 184 controls, in parallel to the first dataset. This allowed internal replication and the power to detect both rare and common signals. Previous PD microbiome studies have ranged from 10 to 197 PD cases and 10 to 130 controls. A microbiome-wide association study uses advances in DNA sequencing and computational tools to look for microbial communities that may be associated with disease. There is emerging understanding that the gut microbiome — which includes 500 to 1,000 bacterial species that have a mainly beneficial influence — plays an important role in human health and disease. Payami and colleagues also used hypothesis-free correlation network analysis to identify communities of co-occurring microorganisms. Network analysis is an important new tool in biology. An easily understood example of networks is a social network like Facebook, where one can map the connections between followers or friends. A few people will have a huge number of connections, some will have many, and a vast majority will have much fewer. A map of these connections is akin to an airline route map. Using network analysis, Payami and colleagues found three polymicrobial clusters, and also found that each cluster shared functional characteristics. The first cluster was that of opportunistic pathogens overabundant in PD cases, a novel finding. The other two clusters were confirmatory of previous studies. In comparison to controls, persons with PD had reduced levels of a cluster of microbes that produce short-chain fatty acids. In the third cluster, the persons with PD had elevated levels of two genera that are carbohydrate-metabolizing probiotic microbes. Payami says the current study had a precise focus and an intentionally strict analytic execution. The rigor of the study included showing that the altered gut microbiomes in the PD cases were independent of sex, age, BMI, constipation, gastrointestinal discomfort, geography and diet. The 15 PD-associated genera that achieved microbiome-wide significance in both datasets were identified using two methods, and with or without covariate adjustment. “There is more to be learned,” Payami said, “with larger sample sizes with greater power, longitudinal studies to track change from prodromal to advanced disease, and by next-generation metagenome sequencing to broaden the scope from bacteria and archaea to include viruses and fungi, and improve the resolution to strain and gene level.” Co-authors with Payami for the study, “Characterizing dysbiosis of gut microbiome in PD: evidence for overabundance of opportunistic pathogens,” published in the Nature partner journal Parkinson’s Disease are Zachary D. Wallen, Mary Appah, Marissa N. Dean, Cheryl L. Sesler and David G. Standaert, UAB Department of Neurology; Stewart A. Factor, Emory University School of Medicine, Atlanta, Georgia; Eric Molho, Albany Medical College, Albany, New York; and Cyrus P. Zabetian, Veterans Administration Puget Sound Health Care System and University of Washington, Seattle, Washington. Support came from National Institutes of Health grants NS036960, NS062684, NS108675 and NS095775. The U.S. Army Medical Research Acquisition Activity, 820 Chandler Street, Fort Detrick, Maryland 21702-5014, is the awarding and administering acquisition office. This work was also supported by the U.S. Army Medical Research Materiel Command endorsed by the U.S. Army, through the Parkinson’s Research Program, under Award Nos. W81XWH1810508 and W81XWH1810509. Opinions, interpretations, conclusions and recommendations are those of the author and are not necessarily endorsed by the U.S. Army. In conducting research using animals, the investigator(s) adheres to the laws of the United States and regulations of the Department of Agriculture. In the conduct of research utilizing recombinant DNA, the investigator adhered to NIH Guidelines for research involving recombinant DNA molecules. In the conduct of research involving hazardous organisms or toxins, the investigator adhered to the CDC-NIH Guide for Biosafety in Microbiological and Biomedical Laboratories. To read the original article click here.

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