Friday, 10 July 2020

COVID-19: Over 80% of young people may show no symptoms

A preliminary study suggests that more than 80% of people aged 20 and under may show no symptoms after contracting SARS-CoV-2. This may have important implications for virus transmission.
Experts from the Bruno Kessler Foundation in Trento, Italy, in collaboration with colleagues affiliated to the ATS Lombardy COVID-19 Task Force and various research institutions, conducted a study assessing what percentage of people who have contracted SARS-CoV-2 are likely to experience any symptoms.
This preliminary study does not yet appear in a peer-reviewed journal, but its authors have made their findings available online, on the preprint platform arXiv.
The rate of likely asymptomatic carriers of the coronavirus could have important implications for viral transmission, the study authors point out.
“This work allows us to clearly show the difficulties in identifying infections with surveillance since the majority of these are not associated with respiratory symptoms or fever,” says study co-author Stefano Merler, who specializes in mathematical modeling of infectious disease transmission.

The researchers analyzed data on 5,484 individuals from the Lombardy region of Italy who had been in contact with people with a new coronavirus infection. Of these, 2,824 individuals had laboratory-confirmed SARS-CoV-2 infections.
Looking at the data, the investigators found that, of the 2,824 individuals with known coronavirus infections, only 876 (31%) had presented any symptoms.
Looking at data on age, the researchers calculated that, among people aged 20 years and under, a probable 81.9% would present no symptoms following infection with the coronavirus.
Among those 80 years of age or over, the investigators estimate that only 35.4% are likely to show no symptoms following infection with the new coronavirus.
Among individuals with a confirmed SARS-CoV-2 infection who were 60 years old and under, 73.9% were likely not to experience fever — body temperature of at least 37.5oC — or respiratory symptoms, the study authors noted.
In terms of general trends, the researchers concluded that the likelihood of experiencing SARS-CoV-2 infection symptoms increased with age.
They also noted that 6.6% of people aged 60 years and older had a severe form of COVID-19 as a result of contracting the new coronavirus, and males had a “significantly higher risk” than females of experiencing a critical state.
Part of what makes the current study important, according to Merler, is that it “also represents a useful piece of information to better understand the role of children in the epidemiology of COVID-19, which we still know very little about.”
“Everyone knows that few positive children were identified during the pandemic,” he says, “but this study allows us to determine the contribution of a possible lower susceptibility to infection in children, which we had identified in a previous study conducted in China, compared to the probability of developing clinical symptoms once infected.”
Source: MedicalNews Today

Monday, 6 July 2020

35% of excess deaths from pandemic not caused by COVID-19

New research suggests that in the United States, around 35% of excess deaths during the early phase of the pandemic were not directly caused by COVID-19.
A new study has found that in the U.S., up to 35% of excess deaths during the early phase of the pandemic may not have been directly due to COVID-19.
The research, which now appears in the journal JAMA, suggests that experts may have underestimated the pandemic’s death toll in publicly reported deaths.

In severe cases, COVID-19 can cause pneumonia: The body’s inflammatory response overcompensates for the presence of the virus in the lungs, reducing the lungs’ ability to get oxygen into the blood.
This can, in turn, lead to organ failure or serious cardiovascular events and, ultimately, death.
However, as well as the direct effects of COVID-19 on a person’s body, the virus can also cause death by exacerbating underlying health issues; the body’s immune system is weakened while fighting off the illness.
Furthermore, the sudden emergence and rapid spread of the disease overwhelmed critical care units when the virus was at its peak, reducing the amount of care any individual patient could receive. This affected not only COVID-19 patients but all those who may have needed critical care.
Consequently, the effect of the pandemic on excess deaths — that is, the number of additional deaths beyond what experts expect of a country during a given time — may be greater than what experts have typically reported, particularly if those reports relied on deaths directly attributed to COVID-19.

This was the finding of a new study that explored the attribution of cause of death for the excess deaths in the U.S. during the early phase of the COVID-19 pandemic.
The study found that death toll reports attributed only 65% of the excess deaths in the U.S. to COVID-19.
Furthermore, in 14 states — including California and Texas, which have large populations — reports linked less than 50% of excess deaths directly to COVID-19.
For lead study author Prof. Steven Woolf, director emeritus of Virginia Commonwealth University’s Center on Society and Health in Richmond, this may mean that experts have underestimated the death toll of the pandemic.
According to Prof. Woolf: “There are several potential reasons for this under-count. Some of it may reflect under-reporting; it takes a while for some of these data to come in. Some cases might involve patients with COVID-19 who died from related complications, such as heart disease, and those complications may have been listed as the cause of death rather than COVID-19.”
“But a third possibility, the one we’re quite concerned about, is indirect mortality — deaths caused by the response to the pandemic. People who never had the virus may have died from other causes because of the spillover effects of the pandemic, such as delayed medical care, economic hardship, or emotional distress.”
– Prof. Steven Woolf
The study also found that excess deaths not linked to COVID-19 rose significantly in states that had the largest outbreaks of the disease during the virus’s peak in early April. These included Massachusetts, Michigan, New Jersey, New York, and Pennsylvania.
For example, in these states, there were 96% more diabetes-related deaths than experts predicted. For heart disease, the figure was 89%; for Alzheimer’s disease, it was 64%; and for stroke, it was 35%.
As well as people not being able to get the necessary treatment due to hospitals being overloaded, the study authors also speculate that people may have stayed at home due to the virus despite experiencing worsening symptoms of another condition they may have had.
They also believe that the pandemic’s effects on people’s mental health may have played a part.
As Prof. Woolf notes: “We can’t forget about mental health. A number of people struggling with depression, addiction, and very difficult economic conditions caused by lockdowns may have become increasingly desperate, and some may have died by suicide. People addicted to opioids and other drugs may have overdosed.”
“All told, what we’re seeing is a death count well beyond what we would normally expect for this time of year, and it’s only partially explained by COVID-19.”
These findings are particularly important, as new cases of the virus are beginning to surge after the relaxation of physical distancing rules in various states across the U.S.
For Prof. Woolf, “[p]ublic officials need to be thinking about behavioral healthcare and ramping up their services for those patients in need. The absence of systems to deal with these kinds of other health issues will only increase this number of excess deaths.”
Source: MedicalNews Today

Tuesday, 30 June 2020

How to Wear Cloth Face Coverings

Cloth face coverings are an additional step to help slow the spread of COVID-19 when combined with every day preventive actions and social distancing in public settings.
  • Who should NOT use cloth face coverings: children under age 2, or anyone who has trouble breathing, is unconscious, incapacitated or otherwise unable to remove the mask without assistance.
  • Cloth face coverings are NOT surgical masks or N95 respirators. Currently, surgical masks and N95 respirators are critical supplies that should be reserved for healthcare workers and other first responders.

Wear your Face Covering Correctly

  • Wash your hands before putting on your face covering
  • Put it over your nose and mouth and secure it under your chin
  • Try to fit it snugly against the sides of your face
  • Make sure you can breathe easily
fitting a cloth facemask to your face. The mask should cover from below your chin to above your nose, and be pinched to fit the bridge of your nose snugly.
people observing social distancing guidelines

Use the Face Covering to Protect Others

  • Wear a face covering to help protect others in case you’re infected but don’t have symptoms
  • Wear the covering in public settings when around people outside of your household, especially when other social distancing measures are difficult to maintain
  • Don’t put the covering around your neck or up on your forehead
  • Don’t touch the face covering, and, if you do, wash your hands

Follow Everyday Health Habits

  • Stay at least 6 feet away from others
  • Avoid contact with people who are sick
  • Wash your hands often, with soap and water, for at least 20 seconds each time
  • Use hand sanitizer if soap and water are not available
Illustration of two individuals with masks on standing 6 feet apart
Illustration of a person removing a face mask

Take Off Your Cloth Face Covering Carefully, When You’re Home

  • Untie the strings behind your head or stretch the ear loops
  • Handle only by the ear loops or ties
  • Fold outside corners together
  • Place covering in the washing machine (learn more about how to wash cloth face coverings)
  • Be careful not to touch your eyes, nose, and mouth when removing and wash hands immediately after removing.

Source: cdc.gov.

Thursday, 25 June 2020

The new coronavirus may spread more easily in crowded homes

A study in New York City revealed a threefold higher risk of infection among pregnant women living in neighborhoods with the most crowded households. Poverty and unemployment also appeared to increase the likelihood of infection.

SARS-CoV-2, which is the coronavirus that causes COVID-19, can spread when a person coughs or sneezes, when they make physical contact with someone else, and when they touch a surface that is contaminated with the virus.
Past research has suggested that housing has a powerful influence on the transmission of infections that spread via physical contact and airborne droplets, such as tuberculosis.
A new study by researchers at Columbia University Irving Medical Center in New York City, NY, suggests that this has contributed to a higher risk of hospitalization with and death from COVID-19 among people who live in the most deprived areas of cities.
“Our study shows that neighborhood socioeconomic status and household crowding are strongly associated with risk of infection,” says study leader Dr. Alexander Melamed, an assistant professor of obstetrics and gynecology at Columbia University Vagelos College of Physicians and Surgeons.
“This may explain why Black and Hispanic people living in these neighborhoods are disproportionately at risk [of] contracting the virus,” he adds.

Dr. Melamed and colleagues investigated SARS-CoV-2 infections among women who lived in the city and gave birth at two hospitals in New York City between March 22, 2020, and April 21, 2020. This was the peak of the outbreak in the city.
A limitation of some other studies examining the risk of contracting the virus is that testing is often restricted to people who are sick. More than 40% of people with the virus may show no symptoms.
However, because all the women in the new study underwent testing on admission to the hospital, its results included those who had the virus but were asymptomatic.
The researchers cross-linked the patients’ home addresses with local data about housing and socioeconomic factors from the United States Census Bureau’s American Community Survey and New York’s Department of City Planning.
Out of the 396 women included in the study, 71 (17.9%) tested positive for the virus.
The odds of infection were three times higher among women who lived in neighborhoods where the average number of people per household was high.
The chance of infection was also two times higher in areas with the most household crowding, which the researchers defined as more than one person per room on average, and in locations with high unemployment rates.
In addition, the likelihood of infection was greater in neighborhoods with high poverty levels. However, this finding was not statistically significant due to the relatively small sample size.

Given these observations, the researchers were surprised to find no evidence of an association between infection and population density.
“New York City has the highest population density of any city in the [U.S.], but our study found that the risks are related more to density in people’s domestic environments rather than density in the city or within neighborhoods,” says study co-author Dr. Cynthia Gyamfi-Bannerman.
This offers hope that public health measures can reduce transmission.
“One may think that because New York City is so dense, there’s little that can slow the spread of the virus, but our study suggests the risk of infection is related to household, rather than urban density,” she adds.
“For our pregnant [population], that may mean counseling women about the risk of infection if they are considering bringing in other family members to help during pregnancy or postpartum.”
The study authors do acknowledge that their findings may not apply to the wider population, given the unique social and biological circumstances of pregnant women.
However, they believe that their work provides an added impetus to reduce the risk of infection in deprived areas where household crowding is a problem.
Source: MedicalNews Today

Tuesday, 23 June 2020

CDC releases consolidated COVID-19 testing recommendations

The Centers for Disease Control and Prevention (CDC) has released consolidated recommendations for COVID-19 testing, including interim testing guidelines for nursing home residents and healthcare personnel, as well as testing strategy options for high-density critical infrastructure workplaces after a COVID-19 case is identified. These recommendations compile and update previous testing guidance.
The consolidated recommendations for testing, Overview of Testing for SARS-CoV-2were developed based on what is currently known about COVID-19 and are subject to change as additional information becomes available. This document includes a summary of current CDC recommendations for testing people who
  • have signs or symptoms of COVID-19;
  • have no symptoms but recently had contact with someone known or suspected to have COVID-19;
  • have no symptoms and no known contact with someone known or suspected to have COVID-19 but still may be tested for early identification in special settings;
  • have had confirmed COVID-19 but no longer have symptoms; and
  • may be tested by public health officials to track spread of the virus that causes COVID-19.
Testing Guidelines for Nursing Homes is an important addition to other infection prevention and control (IPC) recommendations aimed at keeping COVID-19 out of nursing homes (as well as other long-term care facilities), detecting cases quickly if they do occur, and stopping further transmission in these facilities. Nursing home residents are at high risk for infection, serious illness, and death from the disease. Updated recommendations include recommendation against testing the same individual more than once in a 24-hour period; consideration for testing residents with symptoms for other causes of respiratory illness, such as influenza; and coordination of repeat testing in response to outbreaks with local, territorial, and state health departments.
Outbreaks of illness among workers in food-producing facilities and surrounding communities have raised unique questions about testing for COVID-19. Critical infrastructure employers have an obligation to manage the continuation of work in a way that best protects the health of their workers and the general public. Appropriate workplace protections, such as engineering and administrative controls, for those present in the workplace should remain in place. In addition, CDC’s Testing Strategy for Coronavirus (COVID-19) in High-Density Critical Infrastructure Workplaces after a COVID-19 Case is Identified presents different testing strategy options for exposed co-workers when public health organizations and employers determine testing is needed to help support existing disease control measures. Such strategies can aid in identifying infectious individuals with the goal of reducing transmission of SARS-CoV-2 in the workplace.

Source: https://www.cdc.gov/media

Monday, 22 June 2020

Gut bacteria linked to brain blood vessel abnormality

A new study shows that gut bacteria have links to an abnormality in a brain blood vessel that can increase the chances of stroke.

New research has found a link between cavernous angiomas (CA), a type of brain blood vessel abnormality, and the gut microbiome’s composition.
The study further supports emerging research on the significance of the microbiota-gut-brain axis, which is the relationship between bacteria in the gut and how the brain functions.

According to one article, CA are a type of abnormal blood vessel in a person’s brain. Estimates show that 0.5% of the population has them. Of these, 40% become symptomatic, sometimes due to the vessel hemorrhaging.
Symptoms can include headaches, visual disturbances, seizures, or stroke.
Doctors can monitor CA with frequent magnetic resonance imaging (MRI) scans. Some people may require surgery.
Scientists know that CA have a genetic component, so a person may inherit certain gene variants that make developing CA more likely.
However, previous research on mice has shown that the gut microbiome may also affect CA. The microbiome is the collective genome of approximately 100 trillion micro-organisms, primarily bacteria, that live in a person’s gut.
While scientists have suggested a link between the gut microbiome and CA, more detail about what type of microbiome a person with CA has is not available, and few studies have looked at human subjects.
The authors of the present study, which is available in nature communications, wanted to determine what type of bacteria people with CA have, and whether different types of CA correlated to different gut microbiomes.

To do this research, the authors of the present study conducted an advanced genomic analysis of the stool samples of 122 people with at least one identified CA. They compared these samples to a control group matched for age and sex who did not have any CA.
The study found that the CA group had more gram-negative gut bacteria, whereas the control group had more gram-positive gut bacteria.
Further, the study found that particular types of gut bacteria were more prevalent in people with CA, even after they had accounted for possible confounding factors, such as sex, geographic location, or genetics.
The study also identified that the gut bacteria in the people with CA also produced more lipopolysaccharide molecules. The authors noted a link with the production of CA in mice.
As well as indicating a link between types of bacteria and the presence of CA, the study also demonstrated that the composition of some gut bacteria could help identify how aggressive CA might be.
Finally, the study made clear that analyzing the particular type of microbiomes in combination with blood plasma could help clinicians determine the severity of a person’s brain disorder.

The authors suggest that further research should involve larger cohorts and follow-up assessments. They also suggest that it may be valuable to look at the effects of diet on the microbiome and consequently, on CA.
While the research clarifies a link between the gut microbiome and CA, precisely how the two relate is not yet clear.
The microbiota-gut-brain axis is at the forefront of current health science research, and the relationship between the gut and the brain is complex.
However, the study provides further evidence for the importance of the gut-brain relationship and offers more detail on the specifics of CA in relation to gut bacteria.
Source: MedicalNews Today

Thursday, 18 June 2020

How the heart changes our sensory perception

A new study helps explain why our sensitivity to external sensory stimuli fluctuates with the beating of our hearts.
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New research finds a connection between external stimuli and a person’s heart rate.
According to popular culture, the brain and heart work in opposition to each other. The brain is the seat of rational, objective thought, while the heart is emotional and intuitive.
In reality, the activity of the two organs is intimately connected, with neither having a monopoly on reason or emotion.
Our hearts beat faster when we think about something exciting or frightening, for example. Conversely, an early morning jog can brighten our mood as our heart and lungs work harder.
A new study adds to evidence that the brain’s sensitivity to external sensory stimuli changes in step with the beating of the heart.
Researchers at the Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig, and the Berlin School of Mind and Brain, both in Germany, set out to investigate this relationship.

The scientists recruited 37 volunteers and carried out a total of 960 trials. In 800 of these, they gave the participant a mild electric shock to either the middle or index finger of their left hand. The volunteers indicated when they detected the stimulus, and in which finger they felt it.
The researchers told the participants that every trial contained a stimulus, but in the remaining 160 trials, there was no such stimulus.
During each trial, the researchers used electroencephalography (EEG) to record electrical activity in the brain and electrocardiography (EKG) to record the electrical activity of the heart.
They discovered two mechanisms that they believe underpin how the heart influences sensory perception.
The first shows how the phase of the heartbeat might change conscious experience.
Previous research by the same scientists found that during systole, when the heart pumps blood around the body, people are less able to detect and localize a weak electric shock than they are during diastole, when the heart is refilling with blood.
The new study linked this change in sensitivity to a distinctive feature of the brain’s electrical activity known as the P300, which relates to consciousness.
It seems that the P300 signals the extent to which a sensory stimulus is “surprising.” The signal is larger when the stimulus is unexpected, making it more worthy of conscious attention.
The researchers found that the P300 signal dipped during systole. They believe that this may be because the pulse of raised blood pressure that sweeps through the body when the heart contracts is a predictable stimulus that does not merit conscious attention.
It is also important that people do not confuse internal, self-generated stimuli, such as the heartbeat, with external stimuli.
However, the weakened P300 in the brain during systole seems to have the knock-on effect of reducing our sensitivity to sensory stimuli that coincide with it.

The second, related mechanism that connects the heart and sensory perception appears to depend on whether the focus of our attention is inward or outward.
Another distinctive feature of the brain’s electrical activity, known as the heartbeat-evoked potential (HEP), reflects how consciously aware of our heartbeat we are at that moment.
The researchers discovered that when the volunteers’ HEP was strong, they were worse at detecting and localizing the electric shocks.
“This seems to be a result of directing our attention between external environmental signals and internal bodily signals,” explains Esra Al, who led the research.
The brain can rapidly switch conscious attention between internal sensations, such as breathing or heartbeat, and external sensations. It seems that we cannot focus on both simultaneously, though.
Beyond its curiosity value, the new research may also have implications for healthcare.
After a heart attack or stroke, the usual two way communication between heart and brain may become impaired.
“The new results might help to explain why patients after stroke often suffer from cardiac problems and why patients with cardiac disease often have impaired cognitive function,” says senior author Arno Villringer.
Source: MedicalNews Today