Covid’s toll on smell and taste: What scientists do and don’t know

‘Early in the COVID-19 pandemic, it emerged that many people infected with the SARS-CoV-2 virus were losing their sense of smell — even without displaying other symptoms. Researchers also discovered that infected people could lose their sense of taste and their ability to detect chemically triggered sensations such as spiciness, called chemesthesis.

‘Almost a year later, some still haven’t recovered these senses, and for a proportion of people who have, odours are now warped: unpleasant scents have taken the place of normally delightful ones. Nature surveys the science behind this potentially long-lasting and debilitating phenomenon:

• How many people with COVID-19 lose their sense of smell?
• Why do people with COVID-19 lose their sensitivity to smells?
• How quickly do the impaired senses return?
• How does permanently losing the chemical senses affect a person?
• Are treatments available for restoring these senses?

Read here (Nature, Jan 14, 2021)

Covid outbreak data on US carrier shows a plethora of initial symptoms among the symptomatic, only 5.3% fever : NEJM

‘Among the crew members who had symptomatic Covid-19 (confirmed or suspected), headache was the most common symptom reported at any point during illness (occurring in 68.0%), followed by cough (59.5%), nasal or sinus congestion (43.8%), and altered sense of taste or smell (42.3%) (Figure 3). The predominant symptoms reported at the onset of illness were cough (32.8%), headache (31.0%), and altered sense of taste or smell (24.1%). Shortness of breath at any point during illness was reported by 20.3% of the crew members with symptomatic cases, and 7.0% noted shortness of breath as an initial presenting symptom. In addition, 26.2% of the crew members with symptomatic Covid-19 reported chest pain or chest pressure at some point during their illness. Fever was reported as an initial presenting symptom by 5.3% of the crew members with symptomatic Covid-19, and fever at any point during illness was reported by 13.2%. Measured temperature readings showed that 2.8% of the crew members who had Covid-19 had a recorded temperature of 100.0°F or above, as compared with 0.3% of the crew members who did not have Covid-19. Among the crew members with Covid-19 for whom pulse oximetry data were available, approximately 0.5% had readings below 95% while breathing ambient air, with 0.08% below 94% and none below 90%.’

Read here (New England Journal of Medicine, Nov 11, 2020) 

Covid-19 symptoms usually last months, large-scale Dutch survey suggests

‘A survey in the Netherlands has suggested that most people who showed signs of having Covid-19 still had multiple symptoms nearly three months later. Only 0.7 per cent of respondents said they were completely symptom-free 79 days after first showing signs of infection, according to research published on Thursday in the European Respiratory Society’s Open Research journal. The survey is the first to show only a partial recovery among a large sample of people, according to the researchers. It involved more than 2,100 mostly non-hospitalised people confirmed or suspected to have had Covid-19 in the Netherlands and Flanders, the northern Dutch-speaking part of Belgium.’

Read here (South China Morning Post, Sept 11, 2020)

Singapore researchers develop ‘smart mask’ that can monitor signs associated with Covid-19

‘Local scientists have developed an integrated monitoring system that can be easily attached to any face mask in order to monitor the wearer for health indicators associated with Covid-19. Sensors pick up skin temperature, blood oxygen saturation, blood pressure and heart rate - all of which are parameters associated with coronaviruses. Professor Loh Xian Jun, who is one of the scientists behind the invention, told The Straits Times on Thursday (Sept 10) that the inspiration for the system came around the circuit breaker period.’

Read here (Straits Times, Sept 10, 2020)

A supercomputer analysed Covid-19 — and an interesting new theory has emerged: A closer look at the Bradykinin hypothesis

‘Earlier this summer, the Summit supercomputer at Oak Ridge National Lab in Tennessee set about crunching data on more than 40,000 genes from 17,000 genetic samples in an effort to better understand Covid-19. Summit is the second-fastest computer in the world, but the process — which involved analyzing 2.5 billion genetic combinations — still took more than a week.

‘When Summit was done, researchers analyzed the results. It was, in the words of Dr. Daniel Jacobson, lead researcher and chief scientist for computational systems biology at Oak Ridge, a “eureka moment.” The computer had revealed a new theory about how Covid-19 impacts the body: the bradykinin hypothesis. The hypothesis provides a model that explains many aspects of Covid-19, including some of its most bizarre symptoms. It also suggests 10-plus potential treatments, many of which are already FDA approved. Jacobson’s group published their results in a paper in the journal eLife in early July...

‘Covid-19 is like a burglar who slips in your unlocked second-floor window and starts to ransack your house. Once inside, though, they don’t just take your stuff — they also throw open all your doors and windows so their accomplices can rush in and help pillage more efficiently...’

Read here (Elemental Medium, September 1, 2020)

Long-haulers are redefining Covid-19

‘The physical toll of long COVID almost always comes with an equally debilitating comorbidity of disbelief. Employers have told long-haulers that they couldn’t possibly be sick for that long. Friends and family members accused them of being lazy. Doctors refused to believe they had COVID-19. “Every specialist I saw—cardiologist, rheumatologist, dermatologist, neurologist—was wedded to this idea that ‘mild’ COVID-19 infections last two weeks,” says Angela Meriquez Vázquez, a children’s activist in Los Angeles. “In one of my first ER visits, I was referred for a psychiatric evaluation, even though my symptoms were of heart attack and stroke.”

Read here (The Atlantic, August 19, 2020)

US CDC report on symptom duration and risk factors for delayed return to usual health

Symptom duration and risk factors for delayed return to usual health among outpatients with COVID-19 in a multistate health care systems network — United States, March–June 2020

Read here (US CDC, July 24, 2020)

Coronavirus autopsies: A story of 38 brains, 87 lungs and 42 hearts

‘Given widespread reports about neurological symptoms related to the coronavirus, Fowkes [an associate professor of pathology who is part of a team at Mount Sinai Health that has performed autopsies on 67 covid-19 patients] said, she expected to find virus or inflammation — or both — in the brain. But there was very little. When it comes to the heart, many physicians warned for months about a cardiac complication they suspected was myocarditis, an inflammation or hardening of the heart muscle walls — but autopsy investigators were stunned that they could find no evidence of the condition.

‘Another unexpected finding, pathologists said, is that oxygen deprivation of the brain and the formation of blood clots may start early in the disease process. That could have major implications for how people with covid-19 are treated at home, even if they never need to be hospitalized.’

Read here (Washington Post, July 2, 2020)

The long-term effects of Covid-19 infection

‘Some scientists suspect that Covid-19 causes respiratory failure and death not through damage to the lungs, but the brain – and other symptoms include headaches, strokes and seizures... For Julie Helms, it started with a handful of patients admitted to her intensive care unit at Strasbourg University Hospital in northeast France in early March 2020. Within days, every single patient in the ICU had Covid-19 – and it was not just their breathing difficulties that alarmed her. “They were extremely agitated, and many had neurological problems – mainly confusion and delirium,” she says. “We are used to having some patients in the ICU who are agitated and require sedation, but this was completely abnormal. It has been very scary, especially because many of the people we treated were very young – many in their 30s and 40s, even an 18-year-old.”

‘Helms and her colleagues published a small study in the New England Journal of Medicine documenting the neurological symptoms in their Covid-19 patients, ranging from cognitive difficulties to confusion. All are signs of “encephalopathy” (the general term for damage to the brain) – a trend that researchers in Wuhan had noticed in coronavirus patients there in February.’

Read here (BBC, June 23, 2020)

What are the long-term health implications of Covid-19?

‘Six months into the Covid-19 pandemic, and with more than 380,000 people dead, the picture we have of Sars-CoV-2 remains opaque and unclear. Thousands of papers and reports have flooded the academic sphere during this period, as scientists have rushed to understand the virus, which, according to the journal Science, “acts like no pathogen humanity has ever seen”...

‘What initially appeared to be a predictable respiratory infection, similar to Sars or Avian flu, Sars-CoV-2 is now known to affect the lungs, brain, eyes, nose, heart, blood vessels, livers, kidneys and intestines — virtually every organ in the human body.’

Read here (The Independent, June 4, 2020)

Covid-19 can last for several months

I interviewed nine of them [“long-termers” or “long-haulers” who have suffered symptoms for months] for this story, all of whom share commonalities. Most have never been admitted to an ICU or gone on a ventilator, so their cases technically count as “mild.” But their lives have nonetheless been flattened by relentless and rolling waves of symptoms that make it hard to concentrate, exercise, or perform simple physical tasks. Most are young. Most were previously fit and healthy. “It is mild relative to dying in a hospital, but this virus has ruined my life,” LeClerc said. “Even reading a book is challenging and exhausting. What small joys other people are experiencing in lockdown—yoga, bread baking—are beyond the realms of possibility for me.”

Read here (The Atlantic, June 4, 2020)

Coronavirus may be a blood vessel disease, which explains everything

‘A respiratory virus infecting blood cells and circulating through the body is virtually unheard of. Influenza viruses like H1N1 are not known to do this, and the original SARS virus, a sister coronavirus to the current infection, did not spread past the lung. Other types of viruses, such as Ebola or Dengue, can damage endothelial cells, but they are very different from viruses that typically infect the lungs...

‘An infection of the blood vessels would explain many of the weird tendencies of the novel coronavirus, like the high rates of blood clots... Blood vessel damage could also explain why people with pre-existing conditions like high blood pressure, high cholesterol, diabetes, and heart disease are at a higher risk for severe complications from a virus that’s supposed to just infect the lungs.’

Read here (Medium, May 29, 2020)

Coronavirus: 'Baffling' observations from the front line

“It felt in some ways like we were trying to prepare for the D-Day landings," says Barbara Miles, clinical director of intensive care at Glasgow Royal Infirmary, "with three weeks to get ready and not a great deal of knowledge about what we would be facing". But what arrived in the UK as winter turned into spring took even the most experienced ICU specialists by surprise. Most people infected with the coronavirus have only mild symptoms, or sometimes none at all. But in many thousands of patients who fall critically ill, Covid-19 is a disease of alarming complexity.’

Read here (BBC, May 23, 2020)

China’s new outbreak shows signs the virus could be changing

‘Patients found in the northern provinces of Jilin and Heilongjiang appear to carry the virus for a longer period of time and take longer to test negative, Qiu Haibo, one of China’s top critical care doctors, told state television on Tuesday. Patients in the northeast also appear to be taking longer than the one to two weeks observed in Wuhan to develop symptoms after infection, and this delayed onset is making it harder for authorities to catch cases before they spread, said Qiu, who is now in the northern region treating patients.’

Read here (Bloomberg, May 20, 2020)

Unusual symptoms of coronavirus: What we know so far

‘While most people are familiar with the hallmark symptoms of COVID-19 by now—cough, fever, muscle aches, headaches and difficulty breathing—a new crop of medical conditions are emerging from the more than 4 million confirmed cases of the disease around the world.

‘These include skin rashes, diarrhea, kidney abnormalities and potentially life-threatening blood clots. It’s not unusual for viruses to directly infect and affect different tissues and organs in the body, but it is a bit unusual for a primarily respiratory virus like SARS-CoV-2, which is responsible for COVID-19, to have such a wide-ranging reach in the body.’

Read here (Time Magazine, May 19, 2020)

What does recovery from Covid-19 look like?

“Eighty to 85% of our patients who are infected do not need to be hospitalized, but they do require monitoring and medical care, most of which is now taking place with telehealth,” Dr. Ellman says. He says it’s typical for these patients to have a telehealth appointment, either on phone or video, at least every other day for 10 to 14 days from the onset of symptoms...

“Generally speaking, most patients can be managed outside of the hospital,” Dr. Sofair says. “But if you start to get sicker, early treatment can prevent complications. If you do need to be admitted to the hospital, that does not mean you will get really sick. Only a minority of patients end up in the ICU. We have had many good outcomes, and our doctors and nurses now have experience treating this.”

Read here (Yale Medicine, May 18, 2020)

A quarter of Covid-19 patients who died in England had diabetes

‘A quarter of people who died with coronavirus in hospitals in England had diabetes, officials say. People with dementia or lung problems are also among those most at risk of dying after contracting COVID-19, according to new NHS figures.’

Read here (Sky News, May 14, 2020)

How the novel coronavirus attacks our entire body

‘Of course, the lungs and airways are the main focus of attention with the COVID-19 respiratory disease. Since the new SARS-CoV-2 pathogen mainly attacks the lower respiratory tract, infected persons who experience a moderate or severe course of the disease have a dry cough, shortness of breath and/or pneumonia. However, there are now numerous indications that the new coronavirus also attacks other organs on a massive scale and can severely affect the heart, blood vessels, nerves, brain, kidneys and skin.’

Read here (DW, May 11, 2020)

Damage to the kidneys, heart, brain — even ‘covid toes’ — prompts reassessment of the disease and how to treat it

‘...many scientists have come to believe that much of the disease’s devastation comes from two intertwined causes. The first is the harm the virus wreaks on blood vessels, leading to clots that can range from microscopic to sizable. Patients have suffered strokes and pulmonary emboli as clots break loose and travel to the brain and lungs. A study in the Lancet, a British medical journal, showed this may be because the virus directly targets the endothelial cells that line blood vessels. The second is an exaggerated response from the body’s own immune system, a storm of killer “cytokines” that attack the body’s own cells along with the virus as it seeks to defend the body from an invader.

‘Research and therapies are focused on these phenomena. Blood thinners are being more widely used in some hospitals. A review of records for 2,733 patients, published Wednesday in the Journal of the American College of Cardiology, indicates they may help the most seriously ill.’

Read here (Washington Post, May 10, 2020)

‘Finally, a virus got me.’ Scientist who fought Ebola and HIV reflects on facing death from COVID-19

‘Many people think COVID-19 kills 1% of patients, and the rest get away with some flulike symptoms. But the story gets more complicated. Many people will be left with chronic kidney and heart problems. Even their neural system is disrupted. There will be hundreds of thousands of people worldwide, possibly more, who will need treatments such as renal dialysis for the rest of their lives. The more we learn about the coronavirus, the more questions arise. We are learning while we are sailing. That’s why I get so annoyed by the many commentators on the sidelines who, without much insight, criticize the scientists and policymakers trying hard to get the epidemic under control. That’s very unfair.’

Read here (Science, May 8, 2020)