Tag: covid

Categories : Immune SystemTags :

Newly Discovered ‘Goldilocks’ Protein Keeps the Immune System in Check

On By ModernMedia

A newly discovered ‘Goldilocks’ protein may be responsible for helping keep the immune system from running amok, according to researchers at the Lunenfeld-Tanenbaum Research Institute (LTRI).

This protein, known as WAVE2, is expressed in all immune cells and plays a critical role in keeping the immune system in balance. To test its role, researchers knocked out the WAVE2 protein in a subset of immune cells in mice, leading to severe autoimmunity and inflammation, as well as an inability to mount an immune response to a viral infection.

Senior author Dr Kathy Siminovitch, said the team also found that in the absence of WAVE2, another protein, known as mTOR, became overly active, sending the immune system into overdrive and leading to immune cell exhaustion.

“Much like Goldilocks, a proper immune response requires such a delicate balance,” said Dr  Siminovitch. “You have to get it just right. By developing a mouse strain in which T cells, key players in immunity, lack WAVE2, we have shown that this protein is absolutely required for balanced immune responses.”

The question of how to keep the immune system in balance is of key importance in the pandemic, where many deaths occur due to cytokine storms as the immune system overreacts, especially in the elderly. 
As part of her work exploring the mechanisms balancing the immune system, Dr Siminovitch helped trace the complex molecular steps that turn a rare gene mutation into Wiskott-Aldrich syndrome, a potentially lethal disease which impairs the immune system of boys.

Future research would look at how the contribution of the WAVE2-mTOR pathway to specific autoimmune, inflammatory and other conditions, such as Alzheimer’s disease.

Source: News-Medical.Net

Journal information: Liu, M., et al. (2021) WAVE2 suppresses mTOR activation to maintain T cell homeostasis and prevent autoimmunity. Science. doi.org10.1126/science.aaz4544.

Categories : COVIDTags :

Asymptomatic Carriers are the Biggest Barrier to Containing COVID

On By ModernMedia

The lack of testing in asymptomatic carriers makes it harder to control SARS-CoV-2 spread, according to researchers at the Georgetown Center for Global Health Science and Security, Georgetown University in Washington.

Two groups of individuals dominate the transmission of COVID: asymptomatic carriers, who do not develop any symptoms throughout the course of their infection; and presymptomatic carriers, who develop symptoms a few days after being infected.

Transmission without symptoms makes it difficult to estimate the infectious timeline and potential exposures. Asymptomatic cases may likely mingle with others oblivious to their infection, promoting virus spread. They may also not adhere to social distancing, mask wearing etc. Contact tracing is vital to monitor the spread of the disease, and asymptomatic cases makes surveillance to analyse secondary attack rates highly challenging.

Though there is no accurate reporting on the prevalence of asymptomatic cases available, early studies showed that they made up so 30% to 80% of infections. More recent evidence put asymptomatic cases at 17% to 30% of infections.

In COVID cases, the infectious period begins two days before symptom onset and several days thereafter, though viral shedding is reduced in the first week of symptoms.

Viral shedding in asymptomatic cases is poorly understood, however it is known that asymptomatic cases have the same viral load as symptomatic cases, regardless of severity. In asymptomatic individuals, infectious periods are shorter due to reduced titers at peak replication and faster viral clearance.

Some studies have shown that asymptomatic individuals are 42% less likely to infect others and have lower secondary attack rates, while other research indicates that, despite the shorter infectious periods, asymptomatic individuals have similar transmissibility to those who are presymptomatic.
The researchers note that symptomatic individuals were motivated to seek testing, treatment and self-isolate upon feeling COVID symptoms.

“With many contagious people experiencing no symptoms and in the absence of robust surveillance testing for asymptomatic or presymptomatic infections, it is critical to maximising efforts to reduce transmission risk in the community,” noted the researchers.

Source: Medical-News.Net

Journal information: Rasmussen, A., and Popescu, S. (2021). SARS-CoV-2 transmission without symptoms. Science. https://science.sciencemag.org/content/371/6535/1206

Categories : COVIDTags :

Brazil’s ICU Beds Full Amidst ‘Catastrophe’

On By ModernMedia

Brazilian doctors say the situation is “well beyond chaos” even as the country’s COVID-sceptic president refuses to take decisive action against the pandemic.  

An article in The Guardian reports that Brazil is facing the worst medical crisis in its history, as researchers from its leading healthcare institute, Fiocruz, have said the country is entering into a “catastrophe”.

COVID intensive care units in virtually all of the country’s hospitals are either full or almost full, with Fiocruz warning that “The situation is absolutely critical.”

Ricardo Barros, Bolsonaro’s leader in the lower house said on Wednesday: “Our situation isn’t all that critical. Compared to other countries, it’s actually quite comfortable.” This was said on a day in which 2798 fatalities and a record 90 830 new cases were reported.

However, intensive care physicians interviewed by The Guardian tell a different story.

“Things are desperate,” said Dr Hermeto Paschoalick, the head of the critical care unit in the midwestern state of Mato Grosso do Sul, where ICUs are currently 93% full.

Things were worse elsewhere, especially in the state’s capital. “I was told yesterday that there’s a health clinic there with 20 ambulances parked outside. The patients are arriving from small towns in the interior and there’s nowhere to put them – so they just keep them in the ambulances,” said Dr Paschoalick.

Although most in his care were over 60s, Dr Paschoalick said there were young people as well. “Right now, I’ve got three people on ventilators including a 22-year-old woman and another who is 25. Both were pregnant when they arrived. One lost the baby, the other managed to give birth. Both are intubated and in a really bad state,” he said.

Many doctors are forced to choose which patients can receive a bed in ICU.

“People are going around saying Brazil is going to collapse,” said critical care doctor Pedro Carvalho at a university hospital in the riverside town of Petrolina. “But we’ve collapsed already – completely collapsed.” 

Brazil’s President Jair Bolsonaro meanwhile, shows no sign of changing his stance, claiming that there is a “war” against him. 

Source: The Guardian

Categories : Hospitals Mental HealthTags :

Burnout is Highly Prevalent in Healthcare Workers in Cape Town

On By ModernMedia
Image by Free-Photos from Pixabay

Among Cape Town healthcare workers, burnout is highly prevalent, and worsened by the fear of infection, said City spokesperson Priya Reddy.

A year after the breakout of COVID in the Western Cape, the provincial department of health also reported significant levels of burnout among its health-care workers, especially in doctors, nurses and support staff.

Reddy said: “Burnout is highly prevalent as a result of exposure to trauma, loss, grief and compassion fatigue, and is exacerbated by the high levels of anxiety for fear of contracting the virus.”

However, she said: “The presence of Covid-19 has not diverted health-care workers from their primary responsibilities, thus the pandemic added additional levels of care and caution to the way they work and required a major adjustment.”

In response, the City has made available a number of employee assistance programmes (EAP) and wellness interventions to all employees, including City health-care workers and those supporting them in their different functions. The City is also providing workshops on burnout, compassion fatigue and resilience, and making proactive interventions to deal with stress and anxiety.

The provincial health department reported that between October and December last year, 2832 employees accessed the employee health and wellness programme. Work related problems, trauma, COVID related challenges, family challenges and relationships issues were the most common problems presented during this time.

In his review of the pandemic ‘s year in the province, provincial department of health head, Dr Keith Cloete said: “The department recognised the immense impact the pandemic has had on its staff and has initiated intentional healing and grieving sessions with our front-line workers and managers.”

“The department also recognised the need for staff to rest and recuperate, and in between the two waves we encouraged and granted staff to take leave so they can spend some time with family members,” Dr Cloete added.

SA Society of Psychiatrists (Sasop) board member Dr Renata Schoeman said: “Because people on the verge of burnout feel the need to keep going even though they are exhausted and in a state of relentless overwork, by the time they consult a health professional, burnout has often already become depression or anxiety disorder.”

She added: “Avoiding burnout is a classic case where prevention is better than cure, and lifestyle is the most effective preventative strategy. Improving your emotional and mental fitness, as well as physical fitness, helps to build resilience which means you can handle stress better and cope with setbacks.”

A survey of burnout in India found that 52.8% of respondents reported pandemic-related burnout, compared to 26.9% for work-related burnout. Burnout risk was increased by 1.64 for doctors and by 5 for support staff.

Source: IOL

Categories : COVID GeneticsTags :

Bat Coronavirus 94.5% Similar to SARS-CoV-2 Found

On By ModernMedia

Researchers in China and Australia have reported the discovery of novel bat coronaviruses with a similarity of up to 94.5% to SARS-CoV-2. 

This finding further illuminates the diversity and complex evolutionary history of these viruses. A pre-print version of the research paper is available on the bioRxiv server.

Now, Weifeng Shi from Shandong First Medical University & Shandong Academy of Medical Sciences in Taian, China and colleagues have conducted a meta-transcriptomic analysis of samples collected from 23 bat species in Yunnan province in China during 2019 and 2020.  

Using a combination of genome sequencing and sampling studies, researchers identified a number of SARS-CoV-2-related coronaviruses in wildlife species that together pointed to underestimation of the phylogenetic and genomic diversity of coronaviruses.

“Our study highlights both the remarkable diversity of bat viruses at the local scale and that relatives of SARS-CoV-2 and SARS-CoV circulate in wildlife species in a broad geographic region of Southeast Asia and southern China,” said the team.

Bats are hosts to a broad range of viruses that can infect humans, and four of the seven known human coronaviruses have zoonotic origins.  They are also host to many coronaviruses, but sometimes “intermediate” hosts such as dromedary camels (MERS-CoV) are involved in the jump to humans.

Retrospective genome sequencing and sampling studies identified a number of SARS-CoV-2-related coronaviruses in wildlife species. These included the RaTG13 virus, which is the closest known relative of SARS-CoV-2,  found in the Rhinolophus affinis bat. SARS-CoV-2-related viruses have also been identified in various other Rhinolophid bats across Asia.

“Collectively, these studies indicate that bats across a broad swathe of Asia harbour coronaviruses that are closely related to SARS-CoV-2 and that the phylogenetic and genomic diversity of these viruses has likely been underestimated,” said Shi and colleagues.

Notably, one of these novel bat coronaviruses – RpYN06 – exhibited 94.5% sequence identity to SARS-CoV-2 across the whole genome, with key similarities in certain genes. Low genopmic sequence identity in the spike gene made RpYN06 the second closest relative of SARS-CoV-2, next to RaTG13. This is far more similar than seen in other SARS-CoV-2-like viruses identified in wildlife species.

Indeed, while the other three SARS-CoV-2-related viruses identified here were almost identical in sequence, the spike protein sequences formed an independent lineage that was separated from known sarbecoviruses (a  viral subgenus or the coronaviruses that  includesSARS-CoV-2)   by a relatively long branch.

“Collectively, these results highlight the extremely high, and likely underestimated, genetic diversity of the sarbecovirus spike proteins, which likely reflects their adaptive flexibility,” wrote Shi and colleagues.

The researchers say studies have previously shown that host switching of coronaviruses among bats is a frequent occurrence.

Source: News-Medical.Net

Journal information: Shi W, et al. Identification of novel bat coronaviruses sheds light on the evolutionary origins of SARS-CoV-2 and related viruses. bioRxiv. 2021. doi: https://doi.org/10.1101/2021.03.08.434390

Categories : COVID HospitalsTags :

Brazil’s Hospitals Are on The Brink of Collapse

On By ModernMedia

Health systems in most of Brazil’s largest cities are close to collapse because of COVID cases, its leading health institute Fiocruz warns.

More than 80% of intensive care unit beds are occupied in the capitals of 25 of Brazil’s 27 states, Fiocruz said.  The highly contagious variant that emerged in Brazil may have serious knock-on effects for the rest of the world, health experts have warned.

In a stark warning, Fiocruz epidemiologist Jesem Orellana told AFP news agency that  “Brazil is a threat to humanity.”

Brazil’s President Jair Bolsonaro had already provoked outrage among his citizens and rebukes from local leaders by telling people to “stop whining” about COVID. The country recorded 1972 COVID deaths on Tuesday, along with a surge to 70 000 cases — a 38% increase on last week’s figure. ICUs at 15 state capitals are at 90% capacity, said Fiocruz, and in two cities, Porto Alegre and Campo Grande, they had exceeded capacity.

“The fight against COVID was lost in 2020 and there is not the slightest chance of reversing this tragic circumstance in the first half of 2021,” Fiocruz’s Jesem Orellana said, as quoted by AFP.

“The best we can do is hope for the miracle of mass vaccination or a radical change in the management of the pandemic. Impunity in management seems to be the rule.”

Of the currently available vaccines, so far Pfizer’s has been confirmed to be effective in lab tests against a specially engineered version of the virus made to mimic the variant.

Source: BBC News

Categories : COVIDTags :

Bolsonaro Tells Brazilians to ‘Stop Whining’ About COVID

On By ModernMedia

Amidst a surge of COVID cases and deaths in Brazil that have brought its healthcare system to the brink of collapse, President Jair Bolsonaro has told its citizens to “stop whining”, saying that the country must balance economic concerns against controlling the pandemic.

According to Brazil’s health ministry, the country has suffered 260 000 deaths from the virus, the second highest in the world after the United States.

“Stop whining. How long are you going to keep crying about it?” Mr Bolsonaro said at an event. “How much longer will you stay at home and close everything? No one can stand it anymore. We regret the deaths, again, but we need a solution.”

In order to stave off further disaster, a number of local governments have started taking matters into their own hands by imposing their own curfews and other social distancing measures. 

São Paulo’s governor, João Doria, who has been particularly critical of Mr Bolsonaro’s response to the pandemic, called President Bolsonaro “a crazy guy” for attacking “governors and mayors who want to buy vaccines and help the country to end this pandemic”.

“How can we face the problem, seeing people die every day? The health system in Brazil is on the verge of collapse,” Mr Doria said.

This comes as a Duke University scientist, another Bolsonaro critic, warned of the danger of another quarter of a million deaths, and called for an immediate lockdown to help control the situation.

The situation is exacerbated by the emergence of the P.1 variant which emerged in Manaus, and has high transmissibility and the capability to evade immunity, having a 25% to 60% chance of reinfecting an immune individual.

Source: BBC News

Categories : COVID General Interest UncategorizedTags :

Nurse Recounts His Year on the Frontlines

On By ModernMedia
Stethoscope. Photo by Robert Ruggiero on Unsplash

One year into the first case of COVID being detected in South Africa, one nurse recounts the hardships he and other healthcare workers have faced as they battled against the pandemic.

Lebohang Nkoana, a nurse on the frontline at Thelle Mogoerane Hospital in Vosloorus, Ekurhuleni, spoke to IOL of his experiences.

“When Covid-19 came, no one knew what to expect,” said Nkoana, who has been a nurse for eight years and is also a branch secretary for the Democratic Nurses Organisation of SA.

“It was devastating because we were already short-staffed. At first, we were resistant. We did not want to work with Covid-19 patients

“We were just using normal non-sterile gloves. Then we stopped working for two days as we did not want to risk our lives and also because we were not fully informed about the disease.”

Like many in the first days of the pandemic, he was forced to work without adequate PPE. Lack of regulation and price gouging had also worsened the PPE situation during the early days of the pandemic.

“There was no PPE, no increment, nothing. I had to use what I had at my disposal to protect myself and render a service.

“I went into a Covid ward to save lives, but in the process, exposed myself.”

Mr Koana contracted COVID during the course of his duty, and lost 19 of his colleagues to the disease, with little in the way of support for his trauma. He is also stigmatised in his community, as people assume that he has COVID. He also fears for his wife and two children.

“I am not scared for myself, because as a nurse, I took an oath. I am scared for my children. If I bring the virus home and it kills my wife, who will take care of our children?”

Source: IOL

Categories : COVIDTags :

Scientist Issues Stark Warning on Brazil’s COVID Response

On By ModernMedia

If Brazil continues to let COVID rage unchecked, it risks deadly new variants emerging to threaten the global community, a Duke University neuroscientist in Brazil told The Guardian.

Miguel Nicolelis urged the international community to put pressure on the Brazilian government, which has made little effort to manage its COVID outbreak which has so far left a quarter of a million Brazilians dead. Brazil’s COVID deaths amount to one tenth of the world’s total.

“The world must vehemently speak out over the risks Brazil is posing to the fight against the pandemic,” said Nicolelis who has spent much of the lockdown in his São Paulo flat.

“What’s the point in sorting the pandemic out in Europe or the United States, if Brazil continues to be a breeding ground for this virus?”

He said: “It’s that if you allow the virus to proliferate at the levels it is currently proliferating here, you open the door to the occurrence of new mutations and the appearance of even more lethal variants.”

Manaus, the largest city in the Brazilian Amazon, has already seen the emergence of a deadly, highly transmissible variant, P1, six cases of which have been detected in the UK already. The new variant with its “unique constellation of mutations” may also evade immunity, scientists have warned.

“Brazil is an open-air laboratory for the virus to proliferate and eventually create more lethal mutations,” Nicolelis said. “This is about the world. It’s global.”

The warning comes as hospitals around Brazil are on the verge of collapse, with a record 1726 daily deaths recorded on Tuesday.

“We’ve now gone past 250 000 deaths, and my expectation is that if nothing is done we could have lost 500 000 people here in Brazil by next March. It’s a horrifying and tragic prospect, but at this point it’s perfectly possible,” he said.

Nicoleis puts the blame squarely upon Brazil’s far right President Jair Bolsonaro. “The policies that he is failing to put into practice jeopardise the fight against the pandemic in the entire planet.”

José Gomes Temporão, who was the health minister during the 2009 swine flu pandemic, said Bolsonaro and others would have to be held accountable for their poor response.

“To this day, Brazil doesn’t have a national plan to combat COVID,” Temporão complained, criticising Bolsonaro’s failure to secure sufficient vaccines for Brazil. 

“I don’t think there is any other leader who is so obtuse, so backward, who has such a mistaken and warped vision of reality as the president of Brazil,” Temporão said. “History will condemn these people.”

Source: The Guardian

Categories : Cardiovascular Disease COVIDTags :

Study Shows That COVID Causes Heart Damage

On By ModernMedia

Heart problems in COVID are caused by the virus invading heart cells and causing damage, according to a new study.

Heart problems such as arrhythmia and lack of pumping ability were associated with COVID even at the start of the pandemic. However, it was not clear whether these effects were caused by the virus, or whether it was due to the body’s inflammatory response in mounting a defence against the virus. 

“Early on in the pandemic, we had evidence that this coronavirus can cause heart failure or cardiac injury in generally healthy people, which was alarming to the cardiology community,” said senior author Kory J Lavine, MD, PhD, an associate professor of medicine. “Even some college athletes who had been cleared to go back to competitive athletics after COVID-19 infection later showed scarring in the heart. There has been debate over whether this is due to direct infection of the heart or due to a systemic inflammatory response that occurs because of the lung infection.”

Dr Lavine, along with other researchers from the Washington University School of Medicine, engineered stem-cell derived tissue as a model for how human heart tissue contracts. Studying these heart tissue models, they came to the conclusion that the viral infection kills muscle cells as well as the muscle fibre units involved in heart muscle contraction. This cell death and muscle fibre destruction happened even without inflammation.

“Our study is unique because it definitively shows that, in patients with COVID-19 who developed heart failure, the virus infects the heart, specifically heart muscle cells,”  Dr Lavine said. “Inflammation can be a second hit on top of the damage caused by the virus, but the inflammation itself is not the initial cause of the heart injury.”

While other viral infections have been linked to heart damage, SARS-CoV-2 is unique in that monocytes and dendritic cells dominate the immune response, while other viruses that damage the heart attract T and B cells.

“COVID-19 is causing a different immune response in the heart compared with other viruses, and we don’t know what that means yet,” Dr Lavine said. “In general, the immune cells seen responding to other viruses tend to be associated with a relatively short disease that resolves with supportive care. But the immune cells we see in COVID-19 heart patients tend to be associated with a chronic condition that can have long-term consequences. These are associations, so we will need more research to understand what is happening.”

Source: News-Medical.Net

Journal information: Bailey, A. L., et al. (2021) SARS-CoV-2 Infects Human Engineered Heart Tissues and Models COVID-19 Myocarditis. JACC: Basic to Translational Science. doi.org/10.1016/j.jacbts.2021.01.002.