Category: Corona Virus

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A coronavirus uses protein "spikes" to grab and infect cells. Despite their name, those spikes aren't stiff and pointy. They're shaped like chicken drumsticks with the meaty part facing out, and the meaty part can tilt every which way on its slender stalk. That ability to tilt, it turns out, affects how successfully the spike can infect a cell.

Now researchers from the Department of Energy's SLAC National Accelerator Laboratory and Stanford University, along with collaborators at three more universities, have obtained high-resolution images of intact coronavirus spikes on the surfaces of virus particles; identified a tiny hinge surrounded by sugar molecules that allows the spike's glob-like "crown" to bend on its stalk; and measured how far it can tilt in any direction.

While the study was carried out on a much less dangerous cousin of SARS-CoV-2, the coronavirus that causes COVID-19, it has implications for COVID-19, too, since both viruses bind to the same receptor on a cell's surface to initiate infection, said Jing Jin, a biologist at Vitalant Research Institute and adjunct assistant professor at the University of California, San Francisco who performed virology experiments for the study.

The results, she said, suggest that disabling the spike's hinges could be a good way to prevent or treat a wide range of coronavirus infections.

The team also discovered that each coronavirus particle is unique, both in its underlying shape and its display of spikes. Some are spherical, some are not; some bristle with spikes while others are nearly bald.

"The spikes are floppy and move around, and we used a combination of tools to explore all their possible angles and orientations," said Greg Pintilie, a Stanford scientist who developed detailed 3D models of the virus and its spikes. Seen up close, he said, each spike is different from all the rest, mainly in its direction and degree of tilting.

The research team reported its findings in Nature Communications.

"Since the pandemic started, most studies have looked at the structures of coronavirus spike proteins that were not attached to the virus itself," said Wah Chiu, a professor at SLAC and Stanford and co-director of the Stanford-SLAC Cryo-EM facilities where the imaging was done. "These are the first images made of the spikes of this strain of coronavirus while they're still attached to the virus particles."

The study has roots in the early days of the pandemic, when research at SLAC shut down except for work aimed at understanding, preventing and treating COVID-19 infections.

Because experiments with the actual SARS-CoV-2 virus can only take place in high-level (BSL3) biosafety labs, many scientists chose to work with more benign members of the coronavirus family. Chiu and his colleagues selected human coronavirus NL63 as their subject. It causes up to 10% of human respiratory infections, mainly in children and immunocompromised people, with symptoms ranging from mild coughs and sniffles to bronchitis and croup.

In 2020, Chiu said, the team used cryogenic electron microscopy (cryo-EM) and computational analysis to image the crowns of NL63 spikes with near-atomic resolution.

But because a spike's stalk is much thinner than its crown, they were not able to get clear, high-resolution images of both at once.

This study combined information gleaned from a series of experiments to get a much more complete picture.

First, Stanford graduate student David Chmielewski used cryogenic electron tomography (cryo-ET) to combine cryo-EM images of viruses that were taken from different angles into high-resolution 3D images of more than a hundred NL63 particles.

SLAC senior scientist Michael Schmid plugged those images into a 3D visualization tool and discovered that each of a particle's spikes was bent in a unique way. Another SLAC scientist, Muyuan Chen, used advanced image reconstruction to create maps showing the average density of the spikes' crowns and stalks.

Zooming in on one of those spikes, biological chemist Lance Wells at the University of Georgia used a technique called mass spectrometry to pinpoint the site-specific chemical compositions of the 39 sugar chains attached to each of the spike's three identical proteins.

Finally, Abhishek Singharoy, a computational biophysicist at Arizona State University, and his student, Eric Wilson, integrated all those measurements into atomic models of the spikes' crowns and stalks at different bending angles, and carried out further simulations to see how far and how freely a spike can bend.

"It turns out that no matter what, the spikes have a preferred bending angle of about 50 degrees," Chiu said, "and they can tilt up to 80 degrees in any direction in the simulation, which matches well with our cryo-ET experimental observations."

The bending occurred at a place on the stalk, just below the crown, where a particular cluster of sugar molecules clung to the protein, forming a hinge. Computer simulations suggested that changes in the structure of this hinge would affect its ability to bend, and lab experiments went one step further: They showed that mutations in the protein part of the hinge made the spike much less infectious. This suggests that targeting the hinge could provide an avenue to fight the virus.

"People working on the more dangerous coronaviruses, including MERS-CoV and SARS-CoV-2, have identified a region equivalent to this one and discovered antibodies targeting this region," Jin said. "That tells us it's a critical region that is highly conserved, meaning that it has stayed much the same over the course of evolution. So maybe by targeting this region in all coronaviruses, we can come up with a universal therapy or vaccine."

More information: David Chmielewski et al, Structural insights into the modulation of coronavirus spike tilting and infectivity by hinge glycans, Nature Communications (2023). DOI: 10.1038/s41467-023-42836-9

Journal information: Nature Communications

More here:

How tiny hinges bend the infection-spreading spikes of a coronavirus - Phys.org

As you make your shopping list, plan travel, and schedule parties this holiday season, theres something else you should add to your to-do list: making sure youre up-to-date on the latest guidance around COVID-19, the flu, and RSV, as respiratory disease season hits full swing.

It's always important to factor in the possibility of either transmitting an infection to other people or becoming infected, especially when getting together in large groups, says Matthew Binnicker, director of clinical virology at the Mayo Clinic. There are ways to safely gather and enjoy the holiday season, but it requires taking the right precautions.

Heres what to know aboutand how to say safe fromCOVID, the flu, and RSV this holiday season.

Late fall and winter are typically peak times for COVID-19, the flu, and RSV to spreadand mid-November surveillance data suggests all three are already on the rise in the U.S. Based on historical trends, Binnicker says he expects to see continued upticks in infections in late November into December. We typically see a surge in respiratory viruses as the temperatures drop and we proceed into the winter months, he says.

If you havent had COVID-19 or been vaccinated against it in at least six months, Binnicker recommends getting the updated booster shot, which was authorized in September. If you were vaccinated a year ago or two years agoyour immunity likely isnt going to protect you from infection with the currently circulating strains, he says.

As of the two-week period ending Nov. 11, the U.S. Centers for Disease Control and Prevention (CDC) estimated about 50% of new sequenced cases were caused by the Omicron subvariants HV.1 and EG.5. Both are descendants of the XBB family, the lineage vaccine manufacturers designed the latest booster shot to target.

Sooner is better when it comes to getting boosted. You cant get it an hour before and then jump into a party, says Emily Smith, an assistant professor at Duke University with a specialty in global health. It takes about two weeks for the body to mount a full immune response after getting vaccinated.

The same goes for flu shots, Smith says. Recent research suggests you can get your COVID-19 booster and flu shot at the same time without reducing eithers efficacy, so you can schedule both appointments at once.

Finally, those eligiblepeople who are pregnant or elderlyshould consider getting the newly approved RSV vaccine. Young babies can also get an antibody treatment meant to protect against RSV.

The CDC still says anyone who tests positive for COVID-19 should isolate themselves for at least five full days. And through the 10th day after testing positiveeven once the five-day isolation period is overthey should wear a high-quality mask, such as an N95 or KN95, any time they have to be around other people indoors.

If your holiday plans fall within that initial five-day isolation period, the responsible thing to do is the hardest thing to do, which is wait until youre better to see family, Smith says.

The decision is a little trickier if youre done with your five-day isolation, but still within the 10 days of recommended masking. It is possible to be contagious even after your five days of isolation are up, Binnicker notes, so its best to continue taking precautions. If your holiday plans involve being around people who are high-risk for severe disease, including elderly adults or people who are immunocompromised, CDC guidance suggests you should stay home. If you do keep your plans, agency guidance supports staying masked or outdoors the entire time.

The exception: if you test negative on two separate at-home tests taken 48 hours apart, the CDC says you can remove your mask, even if it hasnt been a full 10 days.

While testing requirements for travel are mostly a thing of the past, the CDC still says not to get on planes, trains, or buses during your five-day isolation period. Through day 10, if you absolutely must use public transit, you should remain masked the entire time, unless you've gotten your pair of negative test results.

If youre hosting a party, Smith says its a good idea to ask everyone to test first, particularly if youll have high-risk guests in attendance. Make a game out of it, where people have to test before they come in the house and hand them hot cocoa while they wait, she suggests.

Hosts may also want to keep a supply of masks on hand in case any guests show up ill (or simply want to wear one while around others)or have a plan for moving the party to an outdoor area.

In fact, if the weather in your area allows, consider hosting an entirely outdoor gathering. If its too cold to be outside, Smith says opening a few windows to improve air flow is better than nothing.

At this point, its probably inevitable that there will be many people in the country who will show up to a gathering and someone will be coughing, sneezing, acting visibly unwell, Binnicker says.

If that person turns out to have COVID-19, you dont have to completely isolate yourself unless you also develop symptoms or test positive, the CDC says. However, the agency recommends taking certain precautions in the following days, including wearing a mask when youre around other people indoors, monitoring yourself for symptoms, and testing yourself. Recent research suggests that, after an Omicron exposure, it can take only about three days for an illness to start.

Continue reading here:

How to Handle COVID-19 and Flu During the 2023 Holidays - TIME

In case of a runny nose, you experience excess drainage ranging from a clear fluid to thick mucus from the nose and nasal passages. A runny nose can be caused by colds, flu or even allergies. It is also a symptom associated with a COVID infection in both children and adults. As a result, it can be difficult to tell what your runny nose is caused by.

Its often difficult to tell what exactly is causing the runny nose without a proper diagnosis. If you think you might have COVID-19, the best thing to do is get tested. Further, if you are experiencing other symptoms associated with COVID or might have come in contact with someone else infected, you could have it too.

According to the US CDC, along with a runny nose, other possible COVID symptoms include fever or chills, cough, shortness of breath or difficulty breathing, fatigue, muscle or body aches, headache, new loss of taste or smell, sore throat, nausea or vomiting and diarrhea.

If COVID cases are not widespread where you live, and there are seasonal changes, chances are you might have a runny nose due to allergies, especially if you get them every time with seasonal changes. Other symptoms of allergies include watery eyes, red eyes, itchy eyes, a blocked nose, an itchy nose and sneezing. These signs are more associated with allergies than COVID. The absence of fever can also indicate that a person has allergies instead of COVID-19.

If you have a runny nose, it is important to get adequate rest. Drink plenty of fluids, especially water, to keep your body hydrated. Inhale steam two to four times a day to provide relief from congestion. Use a saline nasal spray to help clear out mucus.

Read more: Exercises to cut down weight gain due to diabetes

If you have a mild infection or allergies, home remedies or over-the-counter medications may provide relief. However, if you feel sick, it is best to see a doctor. It is especially important to urgently see your doctor if you experience any of the following symptoms with COVID difficulty breathing; persistent pain or pressure in the chest; an inability to wake up or stay awake; pale, gray, or blue skin, lips, or nail beds; and confusion.

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Coronavirus: How to tell if your runny nose is due to COVID infection - IndiaTimes

Coronavirus By IANS 6 hours ago TWC India

Representational Image

According to a study, SARS-CoV-2 is likely to follow a seasonal pattern similar to influenza, with the highest rates of infection occurring in colder months in the northern hemisphere and subsiding in summer. As COVID-19 becomes an endemic disease, scientists are attempting to predict the timing of future surges in infections.

"Having some idea of when we'll have surges in the future is important for public health policy and decision-making," said Jeffrey Townsend, Professor of Biostatistics and Ecology and Evolutionary Biology, at Yale University in the US.

"Late fall, winter, and early spring are the highest-risk times for surges of infection," he added.

The research published in the journal mBio can aid clinics and hospitals in preparing for a large number of COVID-19 patients. This prior knowledge is particularly essential since other respiratory viruses, such as influenza and respiratory syncytial virus (RSV), may be active at the same time, adding to the burden on healthcare systems.

To determine future seasonality and when SARS-CoV-2 will be most active, the researchers analysed monthly infection data of common-cold coronaviruses that are often attributed to causing colds. The studies conducted in Europe, East Asia, and North America from 1985 to 2020 had amassed viral samples from thousands of people. Using statistical methods, the team predicted that SARS-CoV-2 would surge in colder months, at least in the temperate places of the Northern Hemisphere they studied.

Nonetheless, the exact timing of the surges will differ by location. It is worth noting that these results apply only when COVID-19 becomes an endemic disease, which has yet to happen. However, most experts believe it is imminent.

Endemicity refers to the virus being steady in the population. The immune systems of the population have been exposed to the virus multiple times, and it spreads the same way every year without interventions. It is unclear how many years it will take to reach that point, but we may be almost there, or it could be another ten years.

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The above article has been published from a wire agency with minimal modifications to the headline and text.

The Weather Companys primary journalistic mission is to report on breaking weather news, the environment and the importance of science to our lives. This story does not necessarily represent the position of our parent company, IBM.

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COVID-19 to Follow Seasonal Pattern Similar to Influenza, Peaking in Colder Months: Study | Weather.com - The Weather Channel

USDA / Bob Nichols

A multinational collection that includes some of the biggest names in poultry production has signed on to an effort to reduce the need for the use of antimicrobials on farms.

The 11 organizationsincluding Cargill Inc., Tyson Foods, McDonalds, the British Poultry Council, Chicken Farmers of Canada, and the Animal Husbandry Association of Vietnamannounced yesterday that they'll adopt antimicrobial stewardship principles developed by the Transformational Strategies for Farm Output Risk Mitigation (TRANSFORM) project. They join 8 other organizations that have already endorsed the principles. Collectively, the 19 organizations represent over 30% of global poultry production.

By advancing science-based antimicrobial use stewardship principles, we are able to create an ecosystem where animal health improves, the need for antibiotic use decreases, and animal production increases.

By committing to these principles, the organizations are agreeing to take a risk-based approach around each instance of antimicrobial use and to adopt farm management practices that improve animal health and reduce the need for antimicrobials. The TRANSFORM principles also call for poultry producers to use antimicrobials only in compliance with national authorizations, and to use medically important antibiotics only under a supervising veterinarian's diagnosis and oversight.

TRANSFORM is a collaboration between Cargill, the International Poultry Council, and Heifer International and is part of the US Agency for International Development's Global Health Security Program. The project is working in Kenya, India, and Vietnam to increase the capacity of small- and large-scale farmers, governments, and agribusinesses to prevent emerging zoonotic diseases and mitigate antimicrobial resistance (AMR).

"By advancing science-based antimicrobial use stewardship principles, we are able to create an ecosystem where animal health improves, the need for antibiotic use decreases, and animal production increases," Annie Kneedler, Chief of Party for TRANSFORM, said in a press release. "These collective efforts contribute to the Global Health Security Agenda goals of reducing the risk of antimicrobial resistance and zoonotic diseases, lessening their impacts on the health of humans around the world."

See more here:

Severe COVID-19 tied to prolonged cough, sputum production in long COVID - University of Minnesota Twin Cities

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Correlation of Diabetic Status and Coronavirus Disease 2019 (COVID-19) in Patients With Mucormycosis: A ... - Cureus

WA Health is re-introducing mask-wearing requirements in public hospitals due to surging COVID cases.

From next Monday staff and patients must wear surgical masks in high-risk hospital clinical areas including haematology, oncology, organ transplant and renal dialysis and around vulnerable patients in critical care settings like intensive care units.

The West Australian is aware of cases of patients dying after contracting the disease in hospital after being admitted with different ailments.

WA Health doesnt track hospital-acquired COVID cases.

There were 57 new hospital admissions and four admissions into an intensive care unit in the week up to November 12.

COVID claimed the lives of four elderly West Australians during the week.

WAs chief health officer Andy Robertson said COVID cases had been increasing in the community since early September 2023 primarily driven by the Omicron XBB variant EG.5.

Its an expected part of the ongoing evolution of COVID-19 in the community as peoples immunity wanes over time, he said.

Given the increase in COVID hospitalisations and health staff off sick, health service providers have agreed on consistent mask recommendations across our public health system.

Previously rules on mask wearing had been devolved to individual units at WA hospitals.

WA Health said surgical masks were recommended for staff and visitors in all public hospital clinical areas and they were reminded to stay home if sick or recovering from COVID.

Dr Robertson on Friday also advised private hospitals and aged care facilities across WA to consider strengthening mask-wearing requirements for staff and visitors.

COVID is very much still with us and my advice for the community remains the same stay home if you are sick and do not visit high-risk settings such as aged care facilities and hospitals if you have cold or flu symptoms, he said.

Consider wearing a mask in crowded indoor settings or where physical distancing is not possible and get a booster COVID-19 vaccination particularly if you have complex health issues or are over 65.

The Australian Medical Association in WA welcomed the move as very sensible given the mounting wave of infections.

I absolutely support the move, president Michael Page said on Friday.

Its about protecting the most vulnerable patients. Patients who have low immunity, due to being on drugs for treating cancers and other reasons, remain vulnerable to severe illness from COVID, including death. For other members of the community to be asked to protect them, by wearing a mask when theyre in proximity to them in a clinical environment is not a big ask of them. I hope the community will understand that and support it.

He encouraged private hospitals to adopt the same measures.

There should be consistency across the health system based on the best clinical advice available at the time, Dr Page added.

To have inconsistency just leads to confusion. Consistency is key.

WA Health said healthcare facilities would continue to implement infection prevention and control measures and precautions including wearing P2/N95 masks when caring for suspected or confirmed COVID-19 cases.

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COVID-19 surge in WA sparks return to masks in hospitals for patients and staff - The West Australian

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Scientists at EPFL have uncovered a cunning strategy that SARS-CoV-2, the virus that causes COVID-19, uses to increase its infectivity.

SARS-CoV-2, the novel coronavirus first identified in late 2019, has since spread globally, leading to the COVID-19 pandemic that has affected millions. As countries grapple with its health, social, and economic impacts, scientists and researchers worldwide have been working tirelessly to understand the virus better and develop effective treatments and vaccines.

In a new study, researchers at EPFL have unveiled a novel mechanism by which SARS-CoV-2 increases its infectivity. The study focuses on the virus's notorious Spike protein, which allows it to enter and infect human cells. The research, now published in Nature Communications, was led by Francisco S. Mesquita and Laurence Abrami in the group of Gisou van der Goot at EPFL's School of Life Sciences.

Upon infecting a host, SARS-CoV-2 manipulates its cellular machinery to modify an enzyme that then turbocharges Spike's ability to invade other cells. The enzyme, abbreviated as ZDHHC20, normally tags proteins with a little fat molecule that changes the way they work.

But upon infection, the virus takes over the ZDHHC20 enzyme. "In our previous work, we discovered the enzyme that modifies the SARS-CoV-2 Spike proteinit adds lipids to itand this is essential for the virus to fuse with target cells," says van der Goot. "What we now show is that the virus actually triggers an optimization of the enzyme by inducing a change in the transcription of its gene."

Analyzing the effects of SARS-CoV-2 on the gene (zdhhc20), the researchers found that the virus triggers a change in its transcriptional start sitethe part of a gene where the process of "reading" it into a protein begins.

Studying both cells in the lab and live organisms, they confirmed that this "transcriptional change" produces an enzyme with 67 additional amino acids. This is enough to increase its lipid-adding activity on Spike 37 times, leading to a heavily enhanced viral infectivity.

The team also used metabolic labeling, Western blotting, and immunofluorescence to visualize and quantify proteins, and get a comprehensive view of the virus's manipulative tactics.

Digging deeper, the researchers found that this change in the transcriptional start of genes seems to be something cells normally do in response to stresses or challengesin the case of the study, chemically induced colitis. What this means is that SARS-CoV-2 hijacks a pre-existing cell damage response pathway to generate more infectious viruses.

The discovery highlights SARS-CoV-2's tactics to boost its infectivity, offering a blueprint for potential treatments, and suggests that other viruses might use similar strategies of co-opting host defenses. Additionally, the findings indicate that the cellular response the virus leverages could be a general reaction to various stresses, which expands the study's findings beyond viral infection.

More information: Francisco S. Mesquita et al, SARS-CoV-2 hijacks a cell damage response, which induces transcription of a more efficient Spike S-acyltransferase, Nature Communications (2023). DOI: 10.1038/s41467-023-43027-2

Journal information: Nature Communications

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How the COVID-19 virus makes itself more infectious - Phys.org

Dual outbreaks of gastro and COVID on the Grand Princess cruise ship that docked in Adelaide on Monday have now been declared over by the doctor on board.

A spokesperson for Princess Cruises, which operates the ship, said a number of passengers had presented with symptoms on a previous voyage. But the ship has since been disinfected and the number of people who were ill when the ship arrived into Adelaide was said to be in single digits.

While this is positive news, reports of infectious outbreaks on cruise ships evoke a sense of deja vu. We probably all remember the high-profile COVID outbreaks that occurred on cruise ships in 2020.

So what is it about cruise ships that can make them such hotspots for infection?

Respiratory infectious outbreaks on cruise ships may be caused by a range of pathogens including SARS-CoV-2 (the virus that causes COVID) and influenza viruses. These can be spread by respiratory droplets and aerosols released when people breathe, talk, laugh, cough and sneeze.

Historically, troop transport ships also helped to spread the lethal 1918 flu virus between continents.

Gastro outbreaks on cruise ships are similarly well documented. More than 90% of cruise ship gastro outbreaks are caused by norovirus, which is spread from person to person, and through contaminated objects or contaminated food or water.

Gastro can also be caused by other pathogens such as bacteria in contaminated food or water.

Read more: Cruise ships can be floating petri dishes of gastro bugs. 6 ways to stay healthy at sea this summer

In 2020, around 19% of Diamond Princess passengers and crew docked in Japan tested positive to COVID. Ultimately, nearly one in four Ruby Princess passengers and crew docked in Sydney tested positive.

However, COVID generally presents a lesser risk nowadays, with most people having some level of immunity from vaccination or previous infection. The outbreak on the Grand Princess appears to have been much smaller in scale.

A three-year study before COVID of influenza-like illness (which includes fever), acute respiratory illness (which doesnt require fever to be present) and gastro on cruise ships found these were diagnosed in 32.7%, 15.9% and 17% of ill passengers, and 10.9%, 80% and 0.2% of ill crew, respectively.

An analysis of data from 252 cruise ships entering American ports showed the overall incidence of acute gastro halved between 2006 and 2019. Passenger cases decreased from 32.5 per 100,000 travel days to 16.9, and crew cases from 13.5 per 100,000 travel days to 5.2. This decline may be due to a combination of improved hygiene and sanitation standards.

The risk of getting sick with gastro was significantly higher on bigger ships and longer voyages. This is because the longer you are in close contact with others, the greater the chance of exposure to an infectious dose of viruses or bacteria.

On cruise ships, people tend to crowd together in confined spaces for extended periods. These include dining halls, and during social activities in casinos, bars and theatres.

The risk goes up when the environment is noisy, as more droplets and aerosols are shed when people are laughing, shouting or talking loudly.

Passengers may come from multiple countries, potentially bringing variants from different parts of the world. Influenza, which is usually seasonal (late autumn to early spring) onshore, can occur at any time on a cruise ship if it has international passengers or is calling at international ports.

Human behaviour also contributes to the risk. Some passengers surveyed following cruise ship gastro outbreaks indicated they were ill when they boarded the ship, or they became ill but didnt disclose this because they didnt want to pay for a doctor or be made to isolate, or they thought it wasnt serious.

Those who became ill were more likely than those who did not to think that hand hygiene and isolation were not effective in preventing infection transmission, and were less likely to wash their hands after using the toilet. Given faecal contamination is a major source of norovirus transmission, this is concerning.

Read more: Cruise ships are back and carrying COVID. No, its not 2020. But heres what needs to happen next

While there are usually a la carte dining options on board, many people will choose a buffet option. From personal experience, food tongs are handled by multiple people, some of whom may not have cleaned their hands.

The Department of Health and Aged Care recommends cruise companies encourage crew and passengers to be up-to-date with flu and COVID vaccinations, and encourage anyone who becomes ill to stay in their cabin, or at least avoid crowded spaces and wear a mask in public.

They also recommend cruise ships have a plan to identify and contain any outbreaks, including testing and treatment capacity, and communicate to passengers and crew how they can reduce their transmission risk.

All passengers and crew should report any signs of infectious illness, and practice good hand hygiene and respiratory etiquette, such as covering their mouth if coughing or sneezing, disposing of used tissues, and washing or sanitising hands after touching their mouth or nose.

Read more: Fleas to flu to coronavirus: how 'death ships' spread disease through the ages

South Australias chief health officer has commended the Grand Princess crew for their infection protection and control practices, and for getting the outbreak under control.

The rest is here:

From COVID to gastro, why are cruise ships such hotbeds of infection? - The Conversation

Scientists are learning more about how long COVID affects the brain. David Wall/Getty Images hide caption

Scientists are learning more about how long COVID affects the brain.

Michelle Wilson got COVID three years ago. She's still waiting for her brain and nervous system to recover.

Wilson's memory is spotty, she's frequently in pain, and even a short walk leaves her exhausted.

"I actually bought a cane that turns into a seat so I can go to the botanical garden," she says.

It's a big change for Wilson, 66, who had worked as a nurse at Barnes-Jewish Hospital in St. Louis. But after years of waiting to get better, she says she's realized something:

"This might be as good as it gets."

It's a story shared by a growing number of COVID "long-haulers" those patients who suffer from persistent symptoms long after the initial infection has passed. Many of those symptoms, experts say, appear to be tied to COVID's effects on the brain and nervous system.

Michelle Wilson receives a coronavirus vaccine at Barnes-Jewish Hospital in St. Louis, Mo. Wilson had gotten COVID earlier in the pandemic, before vaccines were available. Michelle Wilson hide caption

Michelle Wilson receives a coronavirus vaccine at Barnes-Jewish Hospital in St. Louis, Mo. Wilson had gotten COVID earlier in the pandemic, before vaccines were available.

Government surveys suggest that millions of people in the U.S. are living with neurological symptoms linked to long COVID. Many, like Wilson, were infected before vaccines became available.

"It's a public health crisis," says Dr. Robyn Klein, who directs the Center for Neuroimmunology and Infectious Diseases at Washington University School of Medicine in St. Louis.

"There are a lot of people suffering and those people need treatment yesterday," says Dr. Ziyad Al-Aly, who holds positions at both Washington University and the Veterans Affairs St. Louis Health Care System.

But treatment remains a distant promise.

"There's still a ton we don't know," says Dr. Troy Torgerson of the Allen Institute for Immunology in Seattle. Scientists are "nibbling away" at the problem, he says.

The virus appears to do most of its damage to the brain indirectly, scientists say.

An infection in the body triggers an immune response that leads to inflammation in the brain. And the inflammation can persist long after the virus has apparently been cleared, scientists say.

The brain may be especially vulnerable to COVID because the disease appears to weaken the blood-brain barrier, which usually protects the organ from both germs and the immune cells that follow them.

Another possibility is that COVID-related inflammation affects the vagus nerve, which carries signals between the body and brain that are important to memory and attention.

Early in the pandemic, doctors tended to focus on what COVID did to a person's lungs.

In those days, Wilson was working in the post-anesthesia care unit at Barnes-Jewish Hospital.

"I got people ready for surgery, and woke them up after their surgeries," she says. "I loved that job."

But the job put her in close proximity to lots of potentially infected patients. And in November of 2020, Wilson got the disease.

When the symptoms grew worse, she went to the emergency department at her own hospital.

"I had bilateral pneumonia and I was in sepsis by that time," she says. "My blood pressure was really low and I had an irregular heartbeat."

The infection was primarily her lungs, but it was also disrupting her brain, including the circuits that control blood pressure and heart rhythm.

"Unfortunately, long COVID, as we know it now, can affect nearly every organ system, including the brain," Al-Aly says.

People with neurological symptoms do get better, he says, but full recovery is rare.

Three years after getting COVID, Wilson continues to struggle with a range of symptoms, including an unreliable memory.

"I have trouble with word retrieval, concept retrieval and sometimes, like, remembering where I was going," she says.

Wilson also has problems sleeping at night, a condition Al-Aly says affects about 40 percent of people with long COVID.

"As a result, they wake up fatigued," he says, which contributes to their exhaustion from even moderate activity.

Poor sleep can also contribute to the pain that many long COVID patients report.

"It's not only 'my wrist is hurting' or 'my knee is hurting,'" Al-Aly says. "It's really almost like the whole body aches."

When Wilson first came home from the hospital, she was in agony.

"The pain across my chest and in my arms was so bad that I slept with pillows under both arms because I couldn't stand my arms to touch my chest," she says.

Now Wilson is able to do things like make breakfast or take a shower so long as she takes her pain meds.

There's growing evidence that even a mild case of COVID can cause long-term changes to the immune system that affect the brain and nervous system.

Torgerson of the Allen Institute was part of a team that studied blood samples from 55 people who had symptoms at least 60 days after a COVID infection.

"We saw persistent ongoing immune activation in about half," he says, even though only a handful had been sick enough to be hospitalized.

Once the immune system gets fired up, Torgerson says, it can affect the brain even if the virus itself doesn't infect brain cells.

For example, circulating immune cells and antibodies may cross from the bloodstream into the brain and damage neurons. Or the presence of an infection may activate a special set of immune cells found only in the brain.

Long COVID also has some striking similarities to autoimmune diseases, which occur when the immune system mistakenly attacks healthy cells, Torgerson says.

Lupus, for example, can cause inflammation that results in joint pain and fatigue. When Lupus reaches the brain, it can also cause the sort of brain fog often seen in long COVID.

To learn more about how long COVID affects a human brain, scientists have been studying mice that develop a mild version of the disease.

"Those animals have cognitive deficits a month after they were infected," Klein says. "They no longer have virus, they're no longer ill. But they can't remember and recognize things."

One reason may be that the infection weakens the blood-brain barrier in these animals, Klein says, allowing the body's immune response to affect brain cells.

The result is inflammation that causes subtle but significant changes in the brain.

"It's not like there's a multitude of dying neurons," Klein says. "What there is, is elimination of the connections between neurons."

Klein suspects that something similar is happening to the synaptic connections in the brains of people who get long COVID. And she says it appears this can happen even in people who don't get very sick.

"You and I may handle viruses differently," she says. "I may end up getting more inflammation in my brain than you because we have a different genetic makeup."

One way to protect the brain after an infection may be with drugs that reduce inflammation and studies to test that idea are already underway. In the meantime, vaccination offers a way for people to reduce their risk of developing long COVID.

Michelle Wilson, though, got infected before vaccination was an option. And she'd like a treatment that can undo what COVID has done to her brain.

"We don't know everything about COVID yet," she says, "So I have hope."

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Long COVID's effects on the brain help explain many long-haulers' symptoms : Shots - Health News - NPR