Researchers have studied the mechanisms by which the novel coronavirus can reach the brains of patients with COVID-19. The results show that SARS-CoV-2 enters the brain via nerve cells in the olfactory mucosa.

Using post-mortem tissue samples, a team of researchers from Charité — Universitätsmedizin Berlin have studied the mechanisms by which the novel coronavirus can reach the brains of patients with COVID-19, and how the immune system responds to the virus once it does. The results, which show that SARS-CoV-2 enters the brain via nerve cells in the olfactory mucosa, have been published in Nature Neuroscience*. For the first time, researchers have been able to produce electron microscope images of intact coronavirus particles inside the olfactory mucosa.

It is now recognized that COVID-19 is not a purely respiratory disease. In addition to affecting the lungs, SARS-CoV-2 can impact the cardiovascular system, the gastrointestinal tract and the central nervous system. More than one in three people with COVID-19 report neurological symptoms such as loss of, or change in, their sense of smell or taste, headaches, fatigue, dizziness, and nausea. In some patients, the disease can even result in stroke or other serious conditions. Until now, researchers had suspected that these manifestations must be caused by the virus entering and infecting specific cells in the brain. But how does SARS-CoV-2 get there? Under the joint leadership of Dr. Helena Radbruch of Charité’s Department of Neuropathology and the Department’s Director, Prof. Dr. Frank Heppner, a multidisciplinary team of researchers has now traced how the virus enters the central nervous system and subsequently invades the brain.

As part of this research, experts from the fields of neuropathology, pathology, forensic medicine, virology and clinical care studied tissue samples from 33 patients (average age 72) who had died at either Charité or the University Medical Center Göttingen after contracting COVID-19. Using the latest technology, the researchers analyzed samples taken from the deceased patients’ olfactory mucosa and from four different brain regions. Both the tissue samples and distinct cells were tested for SARS-CoV-2 genetic material and a ‘spike protein’ which is found on the surface of the virus. The team provided evidence of the virus in different neuroanatomical structures which connect the eyes, mouth and nose with the brain stem. The olfactory mucosa revealed the highest viral load. Using special tissue stains, the researchers were able to produce the first-ever electron microscopy images of intact coronavirus particles within the olfactory mucosa. These were found both inside nerve cells and in the processes extending from nearby supporting (epithelial) cells. All samples used in this type of image-based analysis must be of the highest possible quality. To guarantee this was the case, the researchers ensured that all clinical and pathological processes were closely aligned and supported by a sophisticated infrastructure.

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Testing half the population weekly with inexpensive, rapid-turnaround COVID-19 tests would drive the virus toward elimination within weeks — even if those tests are significantly less sensitive than gold-standard clinical tests, according to a new study published today by University of Colorado Boulder and Harvard University researchers.

Such a strategy could lead to “personalized stay-at-home orders” without shutting down restaurants, bars, retail stores and schools, the authors said.

“Our big picture finding is that, when it comes to public health, it’s better to have a less sensitive test with results today than a more sensitive one with results tomorrow,” said lead author Daniel Larremore, an assistant professor of computer science at CU Boulder. “Rather than telling everyone to stay home so you can be sure that one person who is sick doesn’t spread it, we could give only the contagious people stay-at-home orders so everyone else can go about their lives.”

For the study, published in the journal Science Advances, Larremore teamed up with collaborators at CU’s BioFrontiers Institute and the Harvard T.H. Chan School of Public Health to explore whether test sensitivity, frequency, or turnaround time is most important to curb the spread of COVID-19.

The researchers scoured available literature on how viral load climbs and falls inside the body during infection, when people tend to experience symptoms, and when they become contagious.

They then used mathematical modeling to forecast the impact of screening with different kinds of tests on three hypothetical scenarios: in 10,000 individuals; in a university-type setting of 20,000 people; and in a city of 8.4 million.

When it came to curbing spread, they found that frequency and turnaround time are much more important than test sensitivity.

For instance, in one scenario in a large city, widespread twice-weekly testing with a rapid but less sensitive test reduced the degree of infectiousness, or R0 (“R naught”), of the virus by 80%. But twice-weekly testing with a more sensitive PCR (polymerase chain reaction) test, which takes up to 48 hours to return results, reduced infectiousness by only 58%. When the amount of testing was the same, the rapid test always reduced infectiousness better than the slower, more sensitive PCR test.

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Researchers have developed a new artificial intelligence platform that detects COVID-19 by analyzing X-ray images of the lungs.

Called DeepCOVID-XR, the machine-learning algorithm outperformed a team of specialized thoracic radiologists — spotting COVID-19 in X-rays about 10 times faster and 1-6% more accurately.

The researchers believe physicians could use the A.I. system to rapidly screen patients who are admitted into hospitals for reasons other than COVID-19. Faster, earlier detection of the highly contagious virus could potentially protect health care workers and other patients by triggering the positive patient to isolate sooner.

The study‘s authors also believe the algorithm could potentially flag patients for isolation and testing who are not otherwise under investigation for COVID-19.

The study will be published on Nov. 24 in the journal Radiology.

“We are not aiming to replace actual testing,” said Northwestern’s Aggelos Katsaggelos, an A.I. expert and senior author of the study. “X-rays are routine, safe and inexpensive. It would take seconds for our system to screen a patient and determine if that patient needs to be isolated.”

“It could take hours or days to receive results from a COVID-19 test,” said Dr. Ramsey Wehbe, a cardiologist and postdoctoral fellow in A.I. at the Northwestern Medicine Bluhm Cardiovascular Institute. “A.I. doesn’t confirm whether or not someone has the virus. But if we can flag a patient with this algorithm, we could speed up triage before the test results come back.”

Katsaggelos is the Joseph Cummings Professor of Electrical and Computer Engineering in Northwestern’s McCormick School of Engineering. He also has courtesy appointments in computer science and radiology. Wehbe is a postdoctoral fellow at Bluhm Cardiovascular Institute at Northwestern Memorial Hospital.

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Although there is much attention being directed toward SARS-CoV-2, the coronavirus at the center of the global pandemic, there are multiple coronaviruses that infect humans.

These seasonal coronavirus infections occur frequently and typically result in a mild, common cold-like illness. The presence of these coronavirus infections in the population has led to the hypothesis that immune cross-reactivity among these related viruses could occur, and potentially offer some protection to SARS-CoV-2. Now, a group of scientists has detected preexisting antibody-driven immunity against SARS-CoV-2 in a small proportion of individuals who were uninfected at the time of sampling.

This work is published in Science in the paper, “Preexisting and de novo humoral immunity to SARS-CoV-2 in humans.”

The four coronaviruses that result in a common cold-like infection when infecting humans are 229E (alpha coronavirus), NL63 (alpha coronavirus), OC43 (beta coronavirus), and HKU1 (beta coronavirus). The other three coronaviruses known to infect humans cause far more serious infections. They are MERS-CoV (the beta coronavirus that causes Middle East Respiratory Syndrome, or MERS), SARS-CoV (the beta coronavirus that causes SARS), and SARS-CoV-2, the novel coronavirus that causes COVID-19.

People around the world commonly get infected with human coronaviruses 229E, NL63, OC43, and HKU1.

The London-based group of researchers found that 16 out of 302 adults (5.3%) harbored IgG antibodies that were likely generated during previous seasonal “common cold” coronavirus infections, and which cross-reacted with subunit S2 of the SARS-CoV-2 spike protein complex.

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Researchers from UCLA believe using plasma could promise a significant breakthrough in the fight against the spread of COVID-19.

In Physics of Fluids, by AIP Publishing, modeling conducted in June showed strains of the novel coronavirus on surfaces like metal, leather, and plastic were killed in as little as 30 seconds of treatment with argon-fed, cold atmospheric plasma.

The researchers used an atmospheric pressure plasma jet they built with a 3D printer to spray surfaces that were treated with SARS-CoV-2 cultures. The surfaces included plastic, metal, cardboard, and basketball, football, and baseball leather.

The spray using plasma fed by argon killed all the coronavirus on the six surfaces in less than three minutes, and most of the virus was destroyed after 30 seconds. Additional testing showed the virus was destroyed in similar times on cotton from face masks.

The novel coronavirus can remain infectious on surfaces for several hours. Author Richard E. Wirz said the findings show great potential for the use of plasma in halting the virus’s transmission cycle.

“This is only the beginning,” Wirz said. “We are very confident and have very high expectations for plasma in future work. In the future, a lot of answers for the scientific community will come from plasma.”

Plasma is one of the four basic states of matter and can be created by heating a neutral gas or subjecting it to a strong electromagnetic field. A relatively new technology, cold atmospheric plasma is an ionized, near-room-temperature gas that has proven effective in cancer treatments, wound healing, dentistry, and other medical applications.

The authors ran a similar coronavirus test with helium-fed plasma, but the helium was not effective, even with treatments up to five minutes. The authors believe this was due to lower rates of reactive oxygen and reactive nitrogen when using helium-fed gas, compared to argon.

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A variant of the coronavirus that is believed to have originated in Spain has spread across Europe and now accounts for most of the new cases reported in several countries in the region, according to the findings of a new study.

The research, which is due to published on Thursday and has not been peer reviewed, details how an international team of scientists has closely monitored the coronavirus through its genetic mutations.

Each variant of the coronavirus has its own genetic signature, meaning it can be traced back to the place it first emerged.

It says a new variant of the disease, identified as 20A.EU1 by researchers from Switzerland and Spain, was first observed in Spain in June. The new variant has been recorded in Spain at frequencies of above 40% since July, the study said.

Elsewhere, the new variant of the coronavirus has increased from “very low” values prior to July 15 to 40% to 70% in Switzerland, Ireland, and the U.K. in September. It was also found to be prevalent in Norway, Latvia, the Netherlands, and France.

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Many COVID-19 survivors are likely to be at greater risk of developing mental illness, psychiatrists said on Monday, after a large study found 20% of those infected with the coronavirus are diagnosed with a psychiatric disorder within 90 days.

Anxiety, depression and insomnia were most common among recovered COVID-19 patients in the study who developed mental health problems, and the researchers also found significantly higher risks of dementia, a brain impairment condition.

“People have been worried that COVID-19 survivors will be at greater risk of mental health problems, and our findings … show this to be likely,” said Paul Harrison, a professor of psychiatry at Britain’s Oxford University.

Doctors and scientists around the world urgently need to investigate the causes and identify new treatments for mental illness after COVID-19, Harrison said.

“(Health) services need to be ready to provide care, especially since our results are likely to be underestimates (of the number of psychiatric patients),” he added.

The study, published in The Lancet Psychiatry journal, analyzed electronic health records of 69 million people in the United States, including more than 62,000 cases of COVID-19.

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The rest of the world joined the celebration today as Pfizer and its German partner BioNTech announced the encouraging results of their candidate in a press release.

Pfizer says it could seek an emergency use authorization (EUA) for the vaccine from the U.S. Food and Drug Administration (FDA) in the next few weeks. But Peter Hotez, a vaccine researcher at Baylor College of Medicine, speaks for many scientists when he says that despite the “apparently good news,” he would keep the champagne corked. “It’s always hard to read the tea leaves of a company press release,” without the underlying data, says Hotez, who is also part of a team making a vaccine against SARS-CoV-2, the virus that causes COVID-19. He stresses that whatever happens, the vast majority of the public will not have access to this or any other COVID-19 vaccine for several months. “This is a slowly evolving process,” Hotez says.

“There are a lot of unanswered questions,” adds Georgetown University’s Jesse Goodman, who was formerly chief scientist at FDA and before that headed its vaccine division. Nothing, for example, is known about how long the immunity triggered by the vaccine will last, whether it can prevent severe COVID-19, and even whether it will slow transmission rates if it’s used widely in a population. It’s unclear how well it works in the elderly, who suffer the most from SARS-CoV-2. The vaccine, based on a simple strand of messenger RNA (mRNA), has to be kept at frigid temperatures below –80°C to preserve the genetic material, and making and delivering it to hundreds of millions—if not billions—of people remain huge challenges.

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Siemens Healthineers has launched a rapid and easy-to-use antigen test for the detection of SARS-CoV-2 in the United Kingdom and other CE countries.

The CLINITEST Rapid COVID-19 Antigen Test is a point-of-care cassette test that does not require laboratory instruments or specialised lab personnel to administer, and it delivers results in 15 minutes.

The CE-marked test, which has been developed and tested by a Siemens Healthineers partner demonstrated 96.72 % sensitivity and 99.22 % specificity based on a clinical study of 317 subjects.

The study was performed using operators with varied credentials at six diverse sites including a hospital, a community clinic, a college campus, and an oncology unit.

Siemens Healthineers intends to meet such testing demand as the pandemic evolves. There are also plans to submit the test for FDA Emergency Use Authorisation in the USA.

“There is a great public need for reliable tests that can quickly identify contagious individuals and help to minimise the spread of COVID-19, especially in high-traffic areas and where people commonly congregate,” states Stewart Hutton, Head of Point of Care Diagnostics at Siemens Healthineers GB&I.

“With quality at the forefront of decision-makers’ criteria to determine test reliability, it was critical the clinical study for this test assessed variable clinical conditions that can be expected when implementing a rapid antigen test.

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A new discovery about how the body transports dexamethasone, a drug that can increase the survival chances of patients with severe COVID-19, suggests diabetes and other factors may reduce its potentially lifesaving effectiveness. Based on their findings, the researchers say doctors may need to rethink how they dose the drug for certain groups of patients.

The team of scientists, based at the University of Virginia School of Medicine, the University of South Carolina, and in Poland, has determined how a protein in our blood called serum albumin picks up dexamethasone and takes it where it is needed. Low serum albumin levels are already considered a major risk factor for severe COVID-19, as is diabetes.

The new research suggests diabetes or low albumin levels may make it difficult for patients to get the benefits of dexamethasone, a corticosteroid that calms the hyperactive immune response that can lead to death in severe COVID-19.

Diabetes is associated with high blood sugar levels, which results in a modification of albumin that may alter the binding site for dexamethasone. Other drugs may also compete with dexamethasone for the limited space in serum albumin’s cargo holds. Albumin’s cargo capacity is also naturally decreased when there is a low albumin level in the blood.

The researchers published their findings in the scientific journal IUCrJ, and the research will be featured on the journal’s cover. The research team consisted of Shabalin, Mateusz P. Czub, Karolina A. Majorek, Brzezinski, Marek Grabowski, David R. Cooper, Mateusz Panasiuk, Maksymilian Chruszcz, and Minor.

 

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