It’s possible that I shall make an ass of myself. But in that case one can always get out of it with a little dialectic. I have, of course, so worded my proposition as to be right either way (K.Marx, Letter to F.Engels on the Indian Mutiny)
Tuesday, October 25, 2022
Sewage monitoring method can trace source of child hepatitis outbreaks
IMAGE: VIALS CONTAINING SEWAGE WATER ARE SCANNED A METHOD FOR MONITORING COVID-19 IN SEWAGE, WHICH CAN ALSO BE USED TO TRACE THE SOURCE OF OTHER OUTBREAKS, INCLUDING MONKEYPOX AND HEPATITIS.view more
CREDIT: MARIEL PEREZ ZABALETA
Researchers in Sweden have created a method that now makes it possible to monitor sewage for a virus that is believed to be linked to hepatitis outbreaks worldwide. First developed for the Covid-19 pandemic, the method can be adapted for a number of viruses, including monkey pox, offering a valuable addition to the public health toolkit.
In a recent study conducted by researchers from KTH Royal Institute of Technology in Stockholm, adenovirus F41 was detected in wastewater samples at the Swedish Environmental Epidemiology Center-KTH node in Stockholm. The results were presented in September to the European Commission and Swedish authorities.
The F41 virus is known for causing outbreaks of gastroenteritis in children—which typically causes diarrhea and vomiting—a condition parents often refer to as “stomach flu.” But a recent outbreak in the U.S. suggested that F41 may also lead to liver inflammation.
Several children in Alabama were hospitalized during the summer with hepatitis symptoms, but they tested negative for hepatitis while testing positive for F41. That outbreak led the U.S. Centers for Disease Control to begin an investigation into the possibility of a link between F41 and hepatitis A, B and C.
KTH researchers Zeynep Cetecioglu Gurol and Mariel Perez Zabaleta say that in the event of such outbreaks, the method could be used by public health authorities to trace the source.
“If we know the water system plan, we can collect wastewater samples close to schools, hospitals or airports,” Cetecioglu Gurol says. “Even if wastewater is mixed from multiple parts of a community, the samples are going to be more concentrated than the samples taken directly from the wastewater treatment plants.”
The researchers adapted a sampling technique that had first been created at KTH in 2020 to monitor Covid-19 virus particles in wastewater collected at Stockholm’s sewage treatment facilities. Perez Zabaleta says the technique can also be used to detect not only F41, but monkey pox and seasonal viruses such influenza and norovirus.
She says the researchers are now adapting their methods to detect the presence of antibiotic resistance via sewage samples.
Animals in national parks impacted by even just a few people
IMAGE: A WOLF SEEN ON A MOTION-ACTIVATED CAMERA IN GLACIER BAY NATIONAL PARK, ALASKA.view more
CREDIT: MIRA SYTSMA
People often visit U.S. national parks to catch a glimpse of wildlife. But how does our presence impact the animals we hope to see?
National park traffic has grown steadily over the past decade, and popular parks like Yosemite and Yellowstone can easily see over a million visitors a year. In these heavily used areas, one might expect animals to change their behavior to avoid humans.
But a new University of Washington-led study has found that even in remote, rarely visited national parks, the presence of even just a few humans impacts the activity of wildlife that live there. Nearly any level of human activity in a protected area like a national park can alter the behavior of animals there, the study found. The research was published Oct. 13 in the journal People and Nature.
“There’s been increasing recognition of how much just the presence of humans in these places, and our recreating there, can impact wildlife,” said senior author Laura Prugh, associate professor in the UW School of Environmental and Forest Sciences. “These results are striking in showing that really any level of human activity can have an effect on wildlife.”
The research team based its study in Glacier Bay National Park, a coastal area in southeast Alaska that is accessible only by boat or plane. Most visitors arrive on cruise ships, but the boats don’t dock on shore, and the park has very little human foot traffic. Because so few people visit each year — only about 40,000 but increasing — the park was an ideal place to locate this study, Prugh explained.
“Glacier Bay is a great park to explore what the lower limits are where humans start to affect wildlife behavior,” Prugh said.
The researchers worked with the national park’s staff to design and implement an experiment that compared wildlife activity in areas used frequently by humans to areas where people were absent. They installed 40 motion-activated cameras across 10 sites to capture detections of people and four animal species — wolves, black bears, brown bears and moose — over two summers. By controlling where and when people could access certain areas of Glacier Bay and then measuring wildlife responses to the differing levels of human activity, the researchers identified two important thresholds.
First, if humans were present in an area, the cameras detected fewer than five animals per week across all four species studied. In most cases, this likely meant that animals avoided areas where humans were present. Second, in backcountry areas, wildlife detections dropped to zero each week once outdoor recreation levels reached the equivalent of about 40 visitors per week.
The researchers were surprised by the apparent low tolerance wildlife had for the presence of people nearby.
“It was eye-opening to see the number of wildlife sightings we are ‘missing’ just by recreating in backcountry areas of Glacier Bay,” said lead author Mira Sytsma, who completed this work as a UW graduate student. “I was surprised that for all four species, wildlife detections were always highest when there wasn't any human activity. So many people visit national parks for the chance to view wildlife, and that desire alone may reduce the chance of it happening.”
Though all four species showed some change in activity due to humans, wolves were most likely to disappear from cameras when people were around. Brown bears were the least impacted by human presence. Moose, however, were more active during the times of day and locations where people were seen. The researchers hypothesize that moose might be using humans as a protective shield from predators, opting to align their active hours with humans to avoid becoming prey.
The researchers expect that in parks where animals are more accustomed to seeing people, at least some individual animals won’t react as strongly to humans as in Glacier Bay. But the findings do shed light on a reality that’s likely playing out at national parks and wilderness areas across the country: More people are visiting these areas than ever before, and the presence of humans is almost certainly impacting the behavior of animals that live there.
“I expect that similar results could be found in other national parks, particularly those with relatively low visitation. I wouldn't be surprised if more and more people seek out less popular national parks to explore, which will have interesting and important implications for park management and wildlife,” Sytsma said.
National parks and wilderness areas aren’t just seeing more visitors during the high season. More people are opting to use the trail systems during less-busy times to avoid crowds. Additionally, some parks are expanding their trail networks to accommodate more visitors.
The authors hope this study can help park managers consider different approaches to making parks accessible both to humans and animals. For example, managers could consider concentrating trails and human use in certain areas to reduce their total footprint, or put restrictions on the time of year or days in which people can visit.
“Our findings lend support to concentrating human activities in some areas, because if you’re going to go above zero human activity and it’s going to have an impact, you might as well go way above zero in some areas and then have other areas where you have almost no human activity,” Prugh said. “In those areas, then, wildlife can live their natural lives unaffected by people.”
Co-authors are Beth Gardner at the UW and Tania Lewis at Glacier Bay National Park and Preserve. This research was funded by the National Park Service.
IMAGE: DISCOVERY IN SOUTHERN CALIFORNIA OF A NEW GENUS AND SPECIES OF THE FAMILY NIMRAVIDAE, PANGURBAN EGIAE, FROM THE EOCENE PERIOD, WITH STRONGLY HYPERCARNIVOROUS FEATURES.view more
CREDIT: KYOTOU/JIM MELLI (SAN DIEGO NATURAL HISTORY MUSEUM)
Dogs, cats, and their close relatives -- existing and extinct -- are members of Carnivoramorpha, a group of mammals in which saber-like canines have evolved twice.
Sabertoothed nimravids were early members of Carnivoramorpha, but dogs and cats did not evolve from them.
"Our specimen has serrated slicing teeth which have important similarities to later predators. The teeth tell us that close relatives of today’s living carnivores spread around the world earlier than we believed, and they diversified quickly when they reached new continents like North America," explains lead author Ashley Poust.
By roughly 40 million years ago, saber-like canines evolved in an ancestral nimravid. By about 16 million years ago, saber-like canines also evolved in an ancestor of a cat subfamily called Machairodontinae, which would give rise to the genus Smilodon about 2.5 million years ago.
"So the nimravids were the original sabretooth carnivores among Carnivoramorpha," explains corresponding co-author Susumu Tomiya of Kyoto University's CICASP.
Now, the team of researchers has re-identified a fossil specimen collected in San Diego in 1997. Earlier, based solely on a partial upper jaw with only two intact teeth and missing saber-like canines, the specimen was misidentified as a Hyaenodon, a separate group of carnivorous mammals.
Further morphological analysis of the tooth shapes, helped to determine that the specimen was one of the earliest nimravids dating back 37 to 40 million years.
"We are excited to honor Dr Naoko Egi, who has added so much to our knowledge of carnivore evolution, by renaming our find as Pangurban egiae," Poust adds.
"The stressed tropical and subtropical ecosystems and movement of species 38 million years ago that resemble changes happening today may have driven the evolution and rise of hypercarnivorous carnivoramorphans, particularly the nimravids."
The first nimravids possibly originated in Asia, and after migrating across vast land masses that are now today's continents, inhabited western North America.
"The discovery of Pangurban egiae reminds us how quickly invasion and adaptation can occur and the large role it has played in the history of life," concludes Poust.
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The paper "An early nimravid from California and the rise of hypercarnivorous mammals after the middle Eocene climatic optimum" appeared on 12 October 2022 in Biology Letters with doi: 10.1098/rsbl.2022.0291
Kyoto University is one of Japan and Asia's premier research institutions, founded in 1897 and responsible for producing numerous Nobel laureates and winners of other prestigious international prizes. A broad curriculum across the arts and sciences at both undergraduate and graduate levels is complemented by numerous research centers, as well as facilities and offices around Japan and the world. For more information, please see: http://www.kyoto-u.ac.jp/en
IMAGE: AN ARTIST'S IMPRESSION OF BETELGEUSE'S SUPERNOVA.view more
CREDIT: EUROPEAN SOUTHERN OBSERVATORY/L. CALÇADA
Astronomers from Liverpool John Moores University and the University of Montpellier have devised an ‘early warning’ system to sound the alert when a massive star is about to end its life in a supernova explosion. The work was published in Monthly Notices of the Royal Astronomical Society.
In this new study, researchers determined that massive stars (typically between 8 and 20 solar masses) in the last phase of their lives, the so-called ‘red supergiant’ phase, will suddenly become around a hundred times fainter in visible light in the last few months before they die. This dimming is caused by a sudden accumulation of material around the star, which obscures its light.
Until now, it was not known how long it took the star to accrete this material. Now, for the first time, researchers have simulated how red supergiants might look when they are embedded within these pre-explosion 'cocoons'.
Old telescope archives show that images do exist of stars that went on to explode around a year after the image was taken. The stars appear as normal in these images, meaning they cannot yet have built up the theoretical circumstellar cocoon. This suggests that the cocoon is assembled in less than a year, which is considered to be extremely fast.
Benjamin Davies from Liverpool John Moores University, and lead author of the paper, says “The dense material almost completely obscures the star, making it 100 times fainter in the visible part of the spectrum. This means that, the day before the star explodes, you likely wouldn't be able to see it was there.” He adds, “Until now, we’ve only been able to get detailed observations of supernovae hours after they’ve already happened. With this early-warning system we can get ready to observe them real-time, to point the world’s best telescopes at the precursor stars, and watch them getting literally ripped apart in front of our eyes.”
IMAGE: INTERFACIAL REACTION DRIVING FORCE TOGETHER WITH CAPILLARY FORCE FACILITATE THE TRANSIENT INFILTRATION OF MOLTEN LI INTO A 3D HOST FOR STABLE 3D COMPOSITE LITHIUM ANODE.view more
CREDIT: NANO RESEARCH, TSINGHUA UNIVERSITY PRESS
As electric vehicles and personal portable electronics become more ubiquitous, researchers are trying to solve some of the major limitations of current lithium-ion battery technology, which uses a graphite anode and a lithium-based transition metal oxide cathode. In contrast, lithium metal batteries, which use a lithium anode in addition to a lithium cathode, may have the potential to solve some of these problems, creating high energy, long-lasting, and safer alternatives to lithium-ion batteries.
For widespread lithium metal battery adoption, two key challenges need to be resolved. The first is that these batteries tend to form accumulations of lithium dendrites, which are metallic deposits. The second is that these batteries have large electrode volume variations. Both problems lead to a decline in performance and safety hazards.
In a paper published in Nano Researchon October 11, researchers describe a technique for developing a three-dimensional composite lithium anode using thermal infusion, which successfully addresses lithium deposition and energy loss during charge cycles.
“Lithium metal batteries emerge as the promising electrochemical storage devices for electric vehicles due to their high energy density; however, these issues related to the growth of lithium dendrites and large electrode volume variations of lithium anode restrict their practical application,” said researcher Feifei Cao of Huazhong Agricultural University in Wuhan, China. “It is highly desirable to explore suitable ways to address the issues of lithium anodes so these batteries can become a more practical option.”
In order to achieve a lithium metal battery that addresses these challenges, researchers created a 3D scaffold and infused molten lithium onto it. The key to ensuring the safety of this technique is using a layer of nanosheets made out of a magnesium-aluminum double oxide. This material is described as lithiophilic, which means it attracts the lithium to generate an alloy medium. The molten lithium is drawn toward the nanosheets and, through capillary action, is brought through the 3D scaffold. This capillary force is extremely important, explained Cao, because it facilitates the transient infiltration of molten lithium into the 3D host, creating a stable 3D composite lithium anode.
Researchers performed rigorous tests on the batteries developed with the new technique. When compared to existing technology, the batteries formed tubular dendrites, but only showed a small thickness fluctuation of 3%. In comparison, without the novel technology, the large electrode grew by 22%. Researchers also tested the battery’s coulombic efficiency or current efficiency, which measures the battery’s capacity and energy loss. After 100 charging cycles, the battery’s efficiency stayed at 98.6%. In comparison, the regular lithium metal batteries saw significant energy loss after only 23 charge cycles.
Looking ahead, researchers are planning how to continue to improve lithium metal batteries so that this technology can be more widely adopted. “For the next step, we will replace the heavy matrix with a light-weight matrix to yield a high weight ratio of active lithium to improve the battery energy density,” said Cao. “We expect to prepare a high safety composite lithium anode that is competitive for high gravimetric energy-density cell with more than 500 Wh kg-1.”
Other contributors include Lan-Xing Li, Yun-Nuo Li, and Huan Ye of the College of Science at Huazhong Agricultural University.
The National Natural Science Foundation of China (Grant Nos. 21975091, 21805105, and 21773078), the Natural Science Foundation of Hubei Province (Program No. 2019CFA046), and the Fundamental Research Funds for the Central Universities of China (Grant No. 2662021JC004) supported this research.
Nano Research is a peer-reviewed, international and interdisciplinary research journal, publishes all aspects of nano science and technology, featured in rapid review and fast publishing, sponsored by Tsinghua University and the Chinese Chemical Society. It offers readers an attractive mix of authoritative and comprehensive reviews and original cutting-edge research papers. After 15 years of development, it has become one of the most influential academic journals in the nano field. In 2022 InCites Journal Citation Reports, Nano Research has an Impact Factor of 10.269 (9.136, 5 years), the total cites reached 29620, ranking first in China's international academic journals, and the number of highly cited papers reached 120, ranked among the top 2.8% of over 9000 academic journals.
SciOpen is a professional open access resource for discovery of scientific and technical content published by the Tsinghua University Press and its publishing partners, providing the scholarly publishing community with innovative technology and market-leading capabilities. SciOpen provides end-to-end services across manuscript submission, peer review, content hosting, analytics, and identity management and expert advice to ensure each journal’s development by offering a range of options across all functions as Journal Layout, Production Services, Editorial Services, Marketing and Promotions, Online Functionality, etc. By digitalizing the publishing process, SciOpen widens the reach, deepens the impact, and accelerates the exchange of ideas.
Washington, October 13, 2022—Earlier elementary school day start times predict less sleep for students but have little to no effect on their educational outcomes, according to new research published today in Educational Evaluation and Policy Analysis, a peer-reviewed journal of the American Educational Research Association. For school districts that must stagger start times for transportation and other logistical reasons, the findings provide evidence that early start times are less detrimental to elementary school students than to students in high school or middle school.
This report on two studies is among the first to look at the impact of changing school start times on elementary students. Traditionally, research on school start times has focused on high schools and middle schools, where the evidence supports later start times based on biological changes in adolescent sleep.
“We found earlier start times for elementary schoolers do not have the same negative effects as they do for middle and high schoolers,” said co-author Sarah Crittenden Fuller, research associate professor in the Department of Public Policy and at the Education Policy Initiative at Carolina (EPIC) at the University of North Carolina. “For elementary students, earlier start times predicted only a slight increase in absences and a small increase in math scores.”
“As a number of districts and, notably, the state of California, adjust school start times to allow high schools and middle schools to start later, our findings offer reassurance that moving elementary schools to earlier start times is unlikely to harm the educational outcomes of the youngest students,” said co-author Kevin C. Bastian, Director of EPIC and research associate professor in the Department of Public Policy.
One of the studies by Bastian and Fuller was broad in scope, covering all public, non-charter elementary schools in North Carolina from 2011–12 through 2016–17, and one focused on an urban district in North Carolina that changed its elementary and high school start times in 2016–17. In each study, the authors examined the relationship between start times and student absences and suspensions as well as achievement on standardized exams.
Bastian and Fuller noted that there is some evidence in their study and other research that school start times have the largest impacts on traditionally disadvantaged groups and that those groups are most likely to be affected by the disruption of changing start times.
“To the extent that districts can change start times to bring middle and high school start times in line with the science on adolescent sleep, this may help close achievement gaps,” said Fuller. “In addition, traditionally disadvantaged groups may benefit most from supports that schools and districts can provide to address disruptions in childcare and transportation created by a change in start times.”
Should the emergence of a new COVID variant or another virus force schools to return to remote learning, the researchers noted that school leaders should carefully consider the best start times rather than simply defaulting to those established for in-person instruction.
Funding note: This research was supported by the Robert Wood Johnson Foundation.
Study citation: Bastian, K.C, & Fuller, S.C. (2022). Early birds in elementary school? School start times and outcomes for younger students. Educational Evaluation and Policy Analysis. Prepublished October 13, 2022. https://doi.org/10.3102/01623737221121799.
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About AERA The American Educational Research Association (AERA) is the largest national interdisciplinary research association devoted to the scientific study of education and learning. Founded in 1916, AERA advances knowledge about education, encourages scholarly inquiry related to education, and promotes the use of research to improve education and serve the public good. Find AERA on Facebook, Twitter, and Instagram.
UNIVERSITY OF ILLINOIS AT URBANA-CHAMPAIGN, NEWS BUREAU
IMAGE: PEOPLE WHO STRONGLY VIEWED SEX AS A LEISURE ACTIVITY BEFORE AND DURING THE PANDEMIC USED THEIR DOWNTIME TO ENGAGE IN MORE FREQUENT, SATISFYING AND CREATIVE SEXUAL ACTIVITY, ACCORDING TO A STUDY BY RECREATION, SPORT AND TOURISM PROFESSOR LIZA BERDYCHEVSKY AT THE UNIVERSITY OF ILLINOIS URBANA-CHAMPAIGN.view more
CREDIT: PHOTO BY L. BRIAN STAUFFER
CHAMPAIGN, Ill. — The fear, uncertainty and stress associated with the COVID-19 pandemic took a toll on adults’ mental and physical health – and their sex lives, several studies reported. However, new research suggests that individuals who embraced sex as a leisure activity found creative ways to cope with the effects of the pandemic and enjoyed more satisfying and active sex lives compared with people who did not view sex the same way.
Researcher Liza Berdychevsky, a professor of recreation, sport and tourism at the University of Illinois Urbana-Champaign, conducted an online survey of 675 adults in the United States, the United Kingdom and Canada between February and May 2021. Published in the journal Leisure Studies, the first paper from the project examined people’s views of sex as leisure before and during the pandemic and the effects those outlooks had on the respondents’ quantity and quality of sex.
The sex-as-leisure perspective was defined in the study as engaging in sexual activity for purposes such as recreation, relaxation, self-gratification or personal development.
“When sexual activity is pleasurable, freely chosen, and intrinsically motivated, it aligns with most definitions of leisure activity,” Berdychevsky said. “The sex-as-leisure mindset affects sexual inhibitions, attitudes and practices, and it is congruent with the view of sexual health as key to our overall wellbeing and quality of life.”
Those who strongly viewed sex as a leisure activity had more resilient sex lives, Berdychevsky found. They reported increased sexual desire, as well as greater variety, frequency and quality of sex compared with people who were less inclined to view sex the same way.
“Viewing sex as leisure minimized the negative effects of the pandemic on people’s sex lives and was linked with greater ability to reach orgasm, heightened sexual intimacy and more touching and caressing,” Berdychevsky said.
“These individuals used the additional time with their partners to devote more time to sexual intimacy, communication and experimentation. Adopting this approach may have been a powerful means for individuals and couples to feel both safe and adventurous in their sex lives during a rather scary time.”
The participants ranged in age from 18-76. The sample included almost 66% women, 30% men and 2.8% individuals who identified differently. About 68% of respondents had a regular sexual partner and 12% had a casual partner.
In another paper from that project, published in the journal Leisure Sciences, Berdychevsky examined the capacity of the sex-as-leisure approach to serve as a coping strategy and whether it was related to a tendency to use and benefit from other sexual coping mechanisms.
Participants were asked whether they engaged in various attitudinal, behavioral and technology-assisted sex-as-leisure coping mechanisms.
The attitudinal strategies included engaging in sex for comfort, pleasure, stress relief or to be playful. The behavioral coping strategies encompassed trying new positions, toys or activities such as bondage and domination or sexual role-playing. And the technology-assisted coping strategies involved watching pornography, sexting and using geo-social networking apps.
Over half of the respondents found sex-as-leisure to be a useful coping mechanism during the pandemic, with many reporting increased feelings of creativity, playfulness and spontaneity. Sex was a source of pleasure, relaxation and comfort for more than two-thirds of the respondents, as well as a means of stress relief, distraction or passing free time.
More than 20% of respondents indulged in long-suppressed sexual fantasies, tried new positions (41%), explored sex toys and aids (26%) or engaged in bondage and domination (18%) or sexual role-playing (13%).
Not surprisingly, with the pandemic’s extended periods of isolation and heightened fears of contagion, the use of technology-mediated coping mechanisms flourished, offering people an outlet for flirting and sexual expression without concerns about safety and social distancing, Berdychevsky found.
Respondents reported that they watched porn alone or with a partner (59% and 17%, respectively), took erotic photos or videos (31%), exchanged erotic notes or emails (25%) or participated in phone or webcam sex (nearly 14%).
Participants reported that they found the behavioral sex-as-leisure coping strategies much more effective than the attitudinal tactics. However, while about 21% of the people surveyed used geo-social networking apps to connect with others, these were rated the least effective of the behavioral coping mechanisms, according to the study.
Initially, Berdychevsky’s data analyses showed that participants’ tendency to view sex as a leisure activity deteriorated, on average, during the pandemic. While a mixture of variables affected the quality of respondents’ sex lives – including age, stress levels and access to a regular sexual partner – when Berdychevsky took a closer look at the data, she found that individuals’ perception of sex as a leisure activity predicted whether their sex lives thrived or deteriorated.
“These results demonstrate that a strong tendency to view sex as leisure served as a protective factor against the adverse impacts of the COVID-19 pandemic on people’s sex lives,” she said. “The decline in people’s tendency to view sex as a form of leisure activity is a potentially problematic health risk factor because this perspective is positively related to all aspects of sexuality, including sexual desire, intimacy and satisfaction.
“Frequent and rewarding sexual activity has been associated with individuals’ greater overall enjoyment of life, quality of life and well-being. It is crucial not to let sexual and relational health become collateral damage of the COVID-19 pandemic. Public health messages educating people to view sex as leisure could help them navigate the impacts and aftermath of the pandemic in their intimate lives and improve their preparedness for future public health crises,” she said.
A new study analyzed genes in nasal swabs from asymptomatic people who tested positive for SARS-CoV-2.
The study found a cluster of people who worked together in a lab that focuses on plasmids.
Plasmids are tiny bits of DNA commonly used to study the proteins produced by viruses.
The analysis attributed the positive tests to the plasmid DNA, not the virus RNA.
The new study shows the importance of considering occupation in diagnostic exams.
Washington, D.C. – For some laboratory workers a positive test for SARS-CoV-2 may more accurately indicate an occupational exposure rather than a viral infection. This week in Microbiology Spectrum, researchers in Seattle report on a small group of laboratory workers whose false positive tests for the virus came not through viral RNA, but instead from a usually harmless bit of DNA, called a plasmid, that’s commonly used to study the virus.
“Plasmids are small DNA structures commonly found in bacteria, and we use them all the time in the lab to make proteins,” said virologist and study leader Lisa Frenkel, M.D., at the University of Washington, who co-directs the Center for Global Infectious Disease Research at Seattle Children’s Research Institute. “And here, the plasmid seemed to take hold in the noses of people who worked with it.” The study also showed that plasmids can spread to other members of a person’s household.
The number of asymptomatic people who test positive and work with SARS-CoV-2 plasmids in labs, is unknown, since most are unlikely to be tested when asymptomatic, Frenkel said.
More importantly, she noted, the new study revealed that plasmids can linger in the nose, probably within bacteria, for weeks. They can interfere with clinical diagnostic tests. When physicians interpret diagnostic results, she said, they should consider a patient’s occupational exposure as well as their medical history.
Frenkel, whose work usually focuses on HIV, did not originally set out to study lab workers or plasmids. But in late March 2020, as COVID-19 case counts grew worldwide, her lab (and those of many colleagues at Seattle Children’s) pivoted to work on SARS-CoV-2. They began looking for biomarkers that could predict how a person would respond to infection. They launched a prospective observational trial that monitored, on a weekly basis, a group of people who had tested positive for SARS-CoV-2 by polymerase chain reaction (PCR) test but didn’t show symptoms.
As they analyzed the data, the researchers realized that 4 of the asymptomatic subjects in their study who tested positive for SARS-CoV-2 by PCR all worked together in the same lab.
“We knew the principal investigator of that lab, and we knew what they were working on,” Frenkel said. Researchers in that lab had been working with a plasmid that encoded a SARS-CoV-2 protein.
That connection raised a question: Could the diagnostic tests be picking up DNA in the plasmid, rather than the virus? After all, PCR tests detect genetic material from the virus. To find out, the researchers analyzed nucleic acids taken from the nasal swabs of the 4 co-workers and one additional participant, a partner of one of the lab workers who was also asymptomatic and testing positive.
Senior scientist Ingrid Beck, M.S., proved that in all cases tested, the detected material came from the plasmid, not the virus. Multiple PCR assays conducted on the specimens amplified DNA sequences unique to the plasmid used in the lab, but not regions of the SARS-CoV-2 RNA. “They had it in their noses for long periods of time, either in nasal tissues or in bacteria,” Frenkel said. The researchers were most likely exposed to the plasmid through their lab work.
The findings raise other questions that remain unanswered. “Now we’re curious, did [the plasmid] vaccinate those people?” Frenkel asked. “We don’t know if they got mucosal immunity to that part of the virus. Could it protect them?”
Since the end of the study, Frenkel has resumed her work on HIV. “SARS-CoV-2 is going to evolve, but luckily it doesn’t evolve as quickly as HIV,” she said. “It’s a virus that we’re able to deal with better than HIV.”
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The American Society for Microbiology is one of the largest single life science societies, composed of more than 30,000 scientists and health professionals. ASM's mission is to promote and advance the microbial sciences.
ASM advances the microbial sciences through conferences, publications, certifications, educational opportunities and advocacy efforts. It enhances laboratory capacity around the globe through training and resources. It provides a network for scientists in academia, industry and clinical settings. Additionally, ASM promotes a deeper understanding of the microbial sciences to diverse audiences.
