Thursday, 4 June 2020

Older men less worried about COVID-19, study suggests

A study has found that older men may worry less about COVID-19 and may be less likely to make behavioral changes in response to the pandemic.

New research has found that despite being a more at-risk demographic, older men are likely to worry less and make fewer behavioral changes in response to the SARS-CoV-2 pandemic.
The research, published in The Journals of Gerontology, concludes that older men might require more education and intervention to ensure that they perceive the risks of COVID-19 accurately.

The sudden emergence and rapid spread of the SARS-CoV-2 virus, as well as the risks associated with contracting COVID-19, have necessitated radical changes in people’s everyday life.
Emerging information about the virus has identified the demographics most vulnerable to a severe reaction to the virus.
While everyone should be making behavioral changes to reduce the spread of the virus, vulnerable groups need to take extra care, since severe COVID-19 can be life threatening.
According to the Centers for Disease Control and Prevention (CDC), 8 out of 10 COVID deaths in the United States have been people aged 65 and over. Research has also shown that men are at higher risk of a worse disease outcome, including death.
Given this, one may expect that men aged 65 and over may be more cautious and more worried about the virus. However, previous research has shown that older men are less likely to worry about death and their mortality than other demographics.
According to Dr. Sarah Barber, a gerontology and psychology researcher at Georgia State University and corresponding author of the study, “[n]ot only do older adults exhibit less negative emotions in their daily lives, they also exhibit less worry and fewer PTSD symptoms following natural disasters and terrorist attacks.
“In normal circumstances, not worrying as much is a good thing. Everyday life is probably happier if we worry less. However, where COVID-19 is concerned, we expected that lower amounts of worry would translate into fewer protective COVID-19 behavior changes.”
The present paper explored whether these known reductions in worry were the same or similar concerning COVID-19 and if this was likely to affect a person’s likelihood of making behavioral changes in response to the virus.

To conduct the research, the authors gathered participants aged 18–35 and 65–81. After excluding participants who had received a diagnosis of COVID-19, the remaining sample consisted of 146 younger people (78 women, 68 men) and 156 older people (74 women, 82 men).
The researchers asked each participant to fill in a questionnaire to assess their relative levels of risk perception, worry, and behavior changes in response to the pandemic.
The researchers assessed the risk by asking if the participants thought people were over-reacting to the virus and if they thought the virus was no worse than seasonal flu. The participants answered the questions according to a scale of 1 (strongly disagree) to 7 (strongly agree).
To assess worry, the participants answered a series of questions about whether they worried about catching COVID-19 or its negative effects on their livelihood. The questionnaire asked the participants to select one of the following options to indicate their levels of worry: (a) not at all, (b) a little, (c) a moderate amount, (d) a lot, and (e) a great deal.
The questionnaire also posed a series of questions to assess behavioral changes. Questions included whether the participants were washing their hands more frequently, if they were wearing a hygiene mask more often, or if they had stopped shaking hands. For each question, participants could respond either (a) Yes, (b) I am considering it, but not yet doing it, and (c) No.

The study found that most people were moderately concerned about the pandemic, and 80% of respondents had made behavioral changes in response to it.
However, the study also found that older men worried less than other participants about COVID-19 and made the fewest changes to their behavior.
Despite these findings, Dr. Barber does not believe the answer is to encourage older men to worry more. As she and co-author Hyunji Kim note, “[w]orry has been associated with increased risk for cardiovascular disease, with poorer physical health, and with greater declines in learning and memory over time.”
Dr. Barber thinks it would be better to ensure older men accurately understand the risks of COVID 19.
“Our study showed that for older men, accurate perception of risk worked as well as worry to predict preventive behaviors,” Dr. Barber said.
An accurate perception of risk may have improved since the researchers conducted the study. Dr. Barber notes that the study took place “right after the pandemic was declared, and we all hope that a more accurate perception of risk has evolved over the last 2 months.”
Nonetheless, the study’s findings indicate the importance of ensuring people, particularly older men, have an accurate perception of the risks of COVID-19.
Source: MedicalNews Today

Monday, 1 June 2020

COVID-19 patients experience neurological symptoms

Altered mental status and stroke are the most common neurological symptoms that hospitalized COVID-19 patients experience, according to a new study from Italy.

People with SARS-CoV-2, which is the virus that causes COVID-19, can experience a variety of symptoms.
According to the Centers for Disease Control and Prevention (CDC), these are usually physical symptoms, such as fever or chills, a cough, fatigue, and shortness of breath.
Among the warning signs that indicate that a person needs emergency medical care, the CDC list confusion and an inability to wake up or stay awake.
Although the neurological symptoms associated with COVID-19 have received much less attention than the physical symptoms, some studies suggest that they are common among people with severe forms of the illness.
A study in the BMJ, for example, found that among COVID-19 patients who died at a hospital in Wuhan, China, 22% had experienced a disorder of consciousness, compared with only 1% of those who recovered.
A preprint of another study of hospitalized patients in China found that overall, 25% had central nervous system symptoms or diseases. These included headaches, dizziness, impaired consciousness, uncoordinated muscle movements, seizures, and strokes.
These were more likely in those with severe disease. For example, 6% in the severe group had strokes, compared with 1% in the non-severe group.
In the first published study of its kind, researchers at the University of Cincinnati in Ohio and several Italian universities analyzed the findings of imaging investigations into hospitalized patients in Italy who experienced neurological symptoms with COVID-19.
The researchers have now published their results in the journal Radiology.

After China, Italy became the second epicenter of the COVID-19 pandemic. Italy has now had more than 33,000 deaths.
The researchers analyzed the records of patients treated at the University of Brescia, the University of Eastern Piedmont in Novara, and the University of Sassari.
Out of 725 patients, 15% experienced neurological symptoms or disease. Of this 15%, 99% underwent a CT scan.
The most common neurological symptoms were “altered mental state,” which 59% of the patients experienced, and ischemic strokes, which 31% of the patients experienced.
“Altered mental status” encompasses a wide range of possible signs and symptoms, including confusion, delirium, and coma.
Among the less common neurological symptoms were headache (12%), seizures (9%), and dizziness (4%).
Imaging revealed acute abnormalities in 47% of the patients. Among the most common findings were ischemic strokes, and in 6% of the patients, there were signs of intracranial hemorrhage.

“These newly discovered patterns could help doctors better and sooner recognize associations with COVID-19 and possibly provide earlier interventions,” says lead study author Dr. Abdelkader Mahammedi, an assistant professor of radiology at the University of Cincinnati.
The study was unable to shed light on whether or not SARS-CoV-2 directly damages the central nervous system. It might be that neurological symptoms are a side effect of critical illness. Lack of oxygen in the brain, for example, can cause confusion or loss of consciousness.
In addition, of the 108 patients, 71% had one or more preexisting chronic conditions. These included hypertension, diabetes, coronary artery disease, and cerebrovascular disease.
In their paper, the researchers cite accumulating evidence to suggest that some people with severe COVID-19 experience a “cytokine storm,” in which the body produces an excess of pro-inflammatory molecules called cytokines. This can cause blood clots, which can, in turn, trigger ischemic strokes.
“This topic definitely needs more research,” says Dr. Mahammedi.
“Currently,” he adds, “we have a poor understanding of the neurological symptoms in COVID-19 patients, whether these are arising from critical illness or from direct central nervous system invasion of SARS-CoV-2. We hope further study on this subject will help in uncovering clues and providing better interventions for patients.”
Source: MedicalNews Today

Sunday, 31 May 2020

Eyes could provide early warning of Alzheimer’s

Working with a mouse model of Alzheimer’s, scientists have developed an imaging technique for detecting changes in the texture of the retina that are associated with the disease. Early diagnosis of the condition could aid efforts to slow its progression.

More than 5 million people aged 65 or older in the United States are living with Alzheimer’s, according to the Alzheimer’s Association. Given the aging population, that number is expected to reach 13.8 million by 2050.
Early intervention with medications and mental exercises can, potentially, slow the development of the disease, but it can be difficult for doctors to make a definitive diagnosis.
There are no clear biological signs, or “biomarkers,” of Alzheimer’s. Instead, doctors rely on indications of cognitive decline and, sometimes, brain scans.
Now, biomedical engineers at Duke University, in Durham, NC, have hit upon a technique that combines two existing technologies to detect signs of the disease in the retina at the back of the eye.
So far, they have only tested this technique in a mouse model of Alzheimer’s. But if it can be shown to work in humans, it could lead to the development of a relatively cheap, compact, and easy to use screening device.
The research appears in the journal Scientific Reports.

According to the researchers, the retina is effectively an extension of the central nervous system and was once considered a window into the brain.
Previous studies have revealed that thinning of the retina is an early sign of Alzheimer’s. However, regular aging and other diseases, such as Parkinson’s and glaucoma, also cause this thinning.
The technology used to measure the thickness of the retina, known as optical coherence tomography (OCT), is like the optical equivalent of ultrasound. It builds up a cross-sectional image of the retina by sending waves of light into the tissues and recording how long they take to come back.
However, OCT can give inconsistent results, due to differences among the machines and how they are operated.
To address the technology’s shortcomings, the Duke researchers combined OCT with an imaging technique called angle-resolved low-coherence interferometry (a/LCI), which analyzes how the retina scatters light to measure its morphology.
In a mouse model of Alzheimer’s, they discovered that the topmost layer of the retina is rougher and more disordered than in mice without the disease.
Other studies have found that the plaques that characterize Alzheimer’s in the brain are also present in this layer of the retina, which is called the nerve fiber layer.
These plaques may be one of the distinctive features that give the retina a rougher, more variable texture in Alzheimer’s.

“Our hope is that we can use this insight to create an easy and cheap screening device that wouldn’t only be available at your doctor’s office but at places like your local pharmacy, as well,” says Adam Wax, a professor of biomedical engineering at Duke and the senior author of the study, which was led by graduate student Ge Song.
“You can’t get textural and structural information about the retina with OCT alone,” explains Song. “You need both imaging modalities. That’s the key innovation.”
Prof. Wax and colleagues are now working to incorporate a/LCI technology in a low-cost OCT device that he is developing through a spinoff company called Lumedica.
Existing OCT devices are bulky, weighing more than 60 pounds, and cost more than $50,000. Prof. Wax says his design weighs only 4 pounds, is about the size of a lunchbox, and could retail for less than $15,000.
Before the technology can be rolled out in clinics, however, the researchers will need to demonstrate that their multimodal imaging device can reliably differentiate between indications of Alzheimer’s, other diseases that affect the retina, and regular aging.
Source: MedicalNews Today

Wednesday, 27 May 2020

Mouthwash may reduce spread of the new coronavirus

A recent scientific review speculates that mouthwash could inhibit the spread of SARS-CoV-2, the virus responsible for COVID-19.

A new research review suggests that publicly available mouthwashes could, in theory, inhibit SARS-CoV-2. The team behind the review call for further research to be done to confirm their speculative findings.

If clinical trials prove effective, the findings, published in the journal Function, may provide another way to reduce the spread of the disease until scientists can produce an effective, publicly available vaccine.
Since the sudden emergence and rapid spread of the SARS-CoV-2 virus, scientists and researchers have focussed on the development of a vaccine that could help protect people vulnerable to COVID-19.
However, scientists have estimated that an effective, publicly available vaccine could take at least 12–18 months to develop.
In the meantime, some scientists are focusing on ways to reduce the rate of infection to controllable levels that will not overwhelm hospital intensive care units.
Other scientists have investigated the development of effective treatments that may reduce the transmission rate of the virus.
One area of research involves disrupting the way the virus can take over a cell of a host as it replicates itself.

SARS-CoV-2, like other coronaviruses, is an enveloped virus. This means that it creates an outer membrane by drawing on the cells of a host organism.
This membrane allows the virus to replicate effectively. If scientists can disrupt this envelope, then this might slow down the spread of the virus within an organism.
Using soap and water or disinfectant can disrupt a viral envelope and kill the virus. Research has shown that disinfectants can kill the SARS-CoV-2 virus.

This is why health authorities and organizations encourage people to wash their hands and surfaces with soap or alcohol-based products regularly.
The present review proposes that some publicly available mouthwashes may be able to help fulfill this role.
Scientists have shown that the virus replicates significantly in the throat. This may mean that a patient with COVID-19 is likely to have the highest concentration of the virus in this area. With high levels of the virus in the throat, it is easy for a person to transmit it through breathing, coughing, and sneezing.
Previous research into alcohol’s ability to disrupt the SARS-CoV-2 envelope has focused on products with a high alcohol content of between 60% and 70%.
This is because manufacturers typically design alcohol-based products to be effective in a variety of circumstances, including viruses, bacteria, and fungi.
However, there is little high-quality research exploring how lower-strength alcohol-based products might affect the viral envelope.

The authors of the current study wanted to see if alcohol-based mouthwashes — which come into contact with a person’s throat, a key site for viral load, and a source of viral transmission — could, in theory, inhibit the transmission of the virus or reduce its severity.
Put simply, if a significant spread of the virus originates from the throat, then it makes sense to trial the efficacy of products that have the potential to kill the virus at this location.
The authors note that due to the speed that the new coronavirus emerged, there is still much to learn about how it functions.
As such, their theory relies on certain assumptions that may turn out to be unfounded.
For example, scientists do not know how the virus moves from a person’s throat or nose to the lungs. The authors note that this could occur through breathing in dead viral cell debris, viral shedding, or neighboring cells becoming infected.
However, given the urgency of the public health crisis, it is necessary to propose speculative theories that scientists can then test in laboratories and, finally, in clinical trials.

Although there is little scientific literature exploring the effects of low-alcohol concentrations on viral envelopes, the authors drew on research that looked at the effects on mammalian cells.
The virus develops its envelope from these cells. So, it may be possible to compare the effects on these cells to the potential effects on the viral envelope.
After studying the literature, the researchers found that there was good reason to suppose that some low-alcohol products would, in theory, be able to disrupt the viral envelope of SARS-CoV-2.
The authors make it clear that their research is speculative. Researchers need to carry out more research to discover whether mouthwashes will affect the new coronavirus.
Nonetheless, this work shows that, in principle, this is a valuable area to study. This type of research is made urgent by the current global public health crisis.
Source: MedicalNews Today

Monday, 25 May 2020

Close relative of SARS-CoV-2 found in bats

Researchers have identified a new coronavirus that is closely related to SARS-CoV-2, the virus behind COVID-19. The discovery provides fresh evidence that SARS-CoV-2 evolved naturally and was not produced in a lab. The new virus is not likely to infect humans.

Since the start of the coronavirus pandemic, rumors have circulated that the SARS-CoV-2 virus, which causes COVID-19, emerged from a laboratory in Wuhan, the city in China where the outbreak began.
This theory was recently given credence by United States President Donald Trump, who claimed to have evidence that SARS-CoV-2 originated in a Chinese laboratory. However, he has not shared any information that would support this claim.
Meanwhile, a growing body of scientific research strongly indicates that SARS-CoV-2 was not manufactured.
New research published in the journal Current Biology adds to the evidence that the virus may have evolved naturally.
The team — led by researchers from Shandong First Medical University, in China — identified a new coronavirus in bats that is closely related to SARS-CoV-2. The two viruses are so closely related that it is highly unlikely that SARS-CoV-2 emerged from a laboratory.

Much of the debate about the origin of the novel coronavirus has centered on its spike protein, with which the virus binds to receptors on a host cell, ultimately allowing the virus to infect the cell and cause disease.
At the point where the two parts of the spike protein meet, there are an extra four amino acids, representing a difference from other coronaviruses. This feature, known as the S1/S2 insertion, is highly unusual and, so far, unique to SARS-CoV-2.
This unique characteristic of the spike protein has fuelled the idea that the virus may have been created in a laboratory.
“Since the discovery of SARS-CoV-2, there have been a number of unfounded suggestions that the virus has a laboratory origin. In particular, it has been proposed the S1/S2 insertion is highly unusual and perhaps indicative of laboratory manipulation,” elaborates senior author Prof. Weifeng Shi, director of the Institute of Pathogen Biology at the university.

In order to compare the novel coronavirus to other, similar viruses, the researchers analyzed the genomes of 302 samples collected from 227 bats. The bats belonged to 20 different species.
The samples were collected from Yunnan province, in China, between May and October 2019 and sent for analysis in early January 2020, soon after SARS-CoV-2 was discovered.
Their genetic analysis identified a new coronavirus, called RmYN02, which has a very similar genome to SARS-CoV-2. The two viruses share 93.3% of their genetic information.
In some genetic regions, the new virus is even more similar than SARS-CoV-2’s current closest relative, RaTG13, which was also identified in bats from Yunnan.
In one of the longest parts of the genome that encodes for protein, RmYN02 shares 97.2% of its RNA with SARS-CoV-2.
Most importantly, according to the authors, RmYN02 has similar amino acid insertions in its spike protein, which suggests that these events — while highly unusual — occur naturally in evolution.

Although the insertions found in the new virus are not exactly the same as those in SARS-CoV-2, the fact that such similar genetic events have occurred in both viruses strongly suggests that they can occur naturally.
The team is hopeful that further investigations will identify other related viruses, eventually helping to explain exactly how SARS-CoV-2 made its way to humans.
It is important to note that the newly identified virus is not likely to infect humans. This is because it does not contain the same receptor-binding domain as SARS-CoV-2, which helps the latter infect human cells.
Source: MedicalNews Today

Thursday, 21 May 2020

Diabetes and COVID-19 in-hospital mortality rates

A recent large-scale study concludes that both type 1 and type 2 diabetes are associated with an increased risk of COVID-19-related in-hospital death. It finds that one-third of coronavirus-related deaths in hospitals in England are individuals with diabetes.

Over the last few months, researchers have rushed to gather information on the effects of a virus that, just last year, was unknown to science. The virus, SARS-CoV-2, causes the disease COVID-19.
Now, with millions of cases globally, scientists are trying to understand which factors have an association with poorer outcomes.
Among these factors is diabetes. As the authors of the recent study explain, early analyses from Italy, China, the United States, and the United Kingdom suggest that individuals with diabetes have an increased risk of developing more severe cases of COVID-19.
However, until now, studies have not differentiated between type 1 and type 2 diabetes; the latest investigation addresses this gap in our understanding.
The findings are available from the U.K.’s National Health Service (NHS) website; they have not yet been peer reviewed and are awaiting publication.

According to the authors, their study is “the largest COVID-19 related study, covering almost the entire population of England, and is the first study to investigate the relative and absolute risks of death in hospital with COVID-19 by type of diabetes, adjusting for key confounders.”
To investigate, the researchers used data from the National Diabetes Audit: an estimated 98% of doctor’s offices in England participated in this program, the purpose of which is to help monitor and improve diabetes services.
The scientists extracted information from the COVID Patient Notification System, which registers all hospital deaths related to COVID-19. They used data from March 1–May 11, 2020.
As part of the analysis, the authors adjusted their findings for factors that might influence the results, such as age, sex, deprivation, ethnicity, and existing health conditions.
Of the 61,414,470 people registered at a doctor’s office in the U.K., 263,830 individuals had a type 1 diabetes diagnosis, and 2,864,670 had a type 2 diabetes diagnosis.
After adjusting for age, sex, deprivation, ethnicity, and geographical region, the researchers found that, compared with individuals without diabetes, people with type 1 diabetes had 3.5 times the odds of dying in the hospital with COVID-19. Similarly, individuals with type 2 diabetes had 2.03 times the odds of dying in the hospital with COVID-19.
When the researchers adjusted the data to account for previous hospital admission with coronary heart disease, cerebrovascular disease, or heart failure, the odds changed to 2.86 and 1.81, respectively.

The authors also looked at other characteristics they associated with in-hospital COVID-19 deaths. They found that the average age of death was 78.6 and that 61.5% were males. They also identified an association between previous coronary heart disease and an increased risk of death.
When they split the data into five levels of depravation, they demonstrated that “The highest proportion of deaths were in those from the most deprived [fifth] of the population (23.8%), decreasing to 15.8% from the least deprived [fifth].”
Their analysis also found an increased risk for people of black, Asian, or mixed ethnicity.
In agreement with earlier research, the authors found that advanced age strongly influences the risk of in-hospital death from COVID-19; they write:
“[T]here is a 700-fold difference in risk between those aged under 40 compared to those over 80.”
The authors continue, “Age was the dominant risk factor for in-hospital death with COVID-19 and had a much greater influence on risk than diabetes status, sex, ethnicity, or socioeconomic deprivation.”
“Even with the additional risk associated with type 1 diabetes or type 2 diabetes,” they emphasize, “people under the age of 40 years with either type of diabetes were at very low absolute risk of in-hospital death with COVID-19 during the observation period of this study in England.”
The authors note that the study was limited because they could not account for all previous or existing medical conditions. In particular, they mention hypertension and chronic kidney disease, which they could not include due to a lack of available data.
In their conclusion, the authors “encourage the use of these findings, along with those from other studies investigating associations with serious COVID-19 related outcomes, to provide reassurance for people who are at low absolute risk, despite having diabetes.”
“For those who are at higher risk,” they explain, “the results inform public guidance, including recommendations for shielding.”
Source: MedicalNews Today

Wednesday, 20 May 2020

Black people four times as likely to test positive for COVID-19

An analysis of the medical records of people who doctors tested for the new coronavirus suggests that the infection exacerbates existing socioeconomic inequalities.
Black people are four times as likely to test positive for SARS-CoV-2, the virus that causes COVID-19, compared with white people, according to a study from the United Kingdom.
The research also found that people living in the most deprived areas were more than three times as likely to test positive in comparison with those living in the least deprived areas.
The analysis, appearing now in The Lancet Infectious Diseases, is one of only a few studies to examine SARS-CoV-2 infection in primary care settings. Most research has been carried out in hospitals and has involved severely ill patients.
The data will help to inform the easing of lockdown measures and public health advice in the U.K. over the coming months.
“While clear trends have emerged from the hospital data for those with severe symptoms, the risk of infection among the general population remains a gray area,” says first author Professor Simon de Lusignan from the University of Oxford, who is also director of the Royal College of General Practitioners Research and Surveillance Centre (RSC).
“It’s important to know which groups in the wider community are most at risk of infection so that we can better understand SARS-CoV-2 transmission and how to prevent new cases,” he continues.

The study analyzed anonymized electronic patient records from 500 GP practice records that automatically upload data to the RSC. The practices are broadly representative of the wider population.
The researchers identified a total of 587 people who tested positive for the virus and 3,215 who tested negative between January 28 and April 4, 2020.
The patients underwent testing after presenting with symptoms of influenza or other respiratory infection.
The proportion of black people who tested positive was 62.1% (36 of 58 people) compared with 15.5% of white people (388 of 2,497 people).
This finding was significant after adjustment for existing conditions such as high blood pressure and diabetes, which are more prevalent among black people and might also raise the risk of SARS-CoV-2 infection.
However, the possibility remains that black people may be more likely to test positive due to other factors, such as where they work.
In their paper, the authors write: “Other socioeconomic factors that we did not measure, such as employment in high risk positions, education, income, and structural barriers to healthcare, might have contributed to this association and should be urgently explored.”
Contrary to an analysis of people who have died with COVID-19 in the U.K., the new study found that Asian people were no more likely than white people to test positive for the infection in primary care, after accounting for other health conditions.
The authors say that their findings relating to ethnicity require caution due to the relatively small numbers from minority ethnic groups in their study.

The difference between people living in the most deprived and least deprived areas was stark.
Of 668 people tested from the most deprived areas, 29.5% (197 people) were positive for the virus, compared with 7.7% (143 out of 1,855 people) in the least deprived areas.
Perhaps, as a result of more opportunities for social mixing, people in urban areas appeared to be more at risk than those in rural areas.
Of 1,816 people tested in urban areas, 26.2% (476 people) were positive, while in rural areas, 5.6% (111 out of 1,986 people) tested positive.
In contrast to analyses of severely ill patients receiving treatment in hospitals, the only preexisting health conditions that doctors could independently associate with testing positive were chronic kidney disease and obesity.
Among people with chronic kidney disease, 32.9% tested positive (68 out of 207 people), compared with 14.4% of those without the disease (519 out of 3,595 people).
While 13.2% of people with a healthy weight tested positive (171 out of 1,296 people), 20.9% of people who were obese tested positive (142 out of 680 people).
In common with other studies, males were more likely than females to test positive, and middle-aged adults were more at risk than children.
Out of 1,612 males who underwent testing, 18.4% (296) were positive, whereas 13.3% of females tested positive (291 out of 2,190 tested).
Among adults aged 40–64 years, 18.5% tested positive (243 out of 1,316 people). By contrast, only 4.6% of children up to 17 years old had positive test results (23 out of 499).

One of the most surprising findings was that smokers were less likely to test positive for SARS-CoV-2 than people who had never smoked.
Of 413 smokers, 11.4% (47 people) tested positive in comparison with 17.9% of nonsmokers (201 out of 1,125 people).
The authors caution: “Our findings should not be used to conclude that smoking prevents SARS-CoV-2 infection, or to encourage ongoing smoking, particularly given the well-documented harms to overall health from smoking, the potential for smoking to increase COVID-19 disease severity, and the possible alternative explanations for these findings.”
The researchers note that smoking may affect the sensitivity of the test by reducing the concentration of virus particles in the nose and throat. In addition, smokers may be more likely to have a cough and, therefore, may be more likely to submit themselves for testing.
Selection bias could potentially affect all the results due to certain groups being more or less likely to present themselves for testing.
Source: MedicalNews Today