"Weekly Coronavirus Questions"

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trader32176
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"Weekly Coronavirus Questions"

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"Weekly Coronavirus Questions"

October 2, 2020


https://www.npr.org/sections/goatsandso ... that-helpf

More and more places want to take my temperature before letting me in, with some kind of device they aim at my head. What are the benefits — and drawbacks?

If you go out and about during this pandemic, you're probably going to get your temperature taken. Often.

At the dentist's office, at a gym or exercise class, even at some restaurants and grocery stores, a staffer will use a non-contact infrared thermometer (aka a no-touch temperature gun) to see if you are feverish — a symptom that could be a sign of infection with the coronavirus. The device, which looks like a laser gun, is pointed at your forehead and registers body temperature in a matter of a few seconds.

And increasingly, those scans are becoming the norm in airports, hospitals and workplaces around the globe, from the U.S. to India.

At the presidential debate Tuesday in Cleveland, authorities temperature-checked all attendees, according to NPR correspondent Scott Detrow, who attended the event. "There was a big sensor pointing at us, and you could see there was a video camera that put a thermal temperature bubble over everybody," he says. "The sensor picked up people's temperatures, then displayed them on two large screens."

The reason for this surge in temperature taking is clear. If people are running a fever, they're turned away at the door. Fever can be (but isn't always) a sign of COVID-19, the disease caused by the novel coronavirus.

But what can the results of a temperature scan really tell us?


Sonali Advani, an assistant professor of medicine at Duke University, distills the issue into two main questions.

The first is fundamental: Do infrared temperature guns get an accurate temperature read?

In broad terms, research points to yes.

"In general, they've shown to work reasonably well," Advani says,

Harvard Medical School physician Abraar Karan explains that studies have shown that the readings on infrared thermometers are comparable to digital thermometers. In one paper that looked at temperature scans of newborns with normal and touchless infrared thermometers, for instance, the two often had close concordance in readings.

That said, infrared thermometer guns can be a bit hard to use — and the scan results can be susceptible to outside influence.

The reason: "Infrared thermometers look at skin temperature, which can vary from core temperature," Karan says. "And skin temperature can be affected by humidity, sweat [or other weather conditions], interrupting the interface between the device and skin."

In other words, if you were to run to the gym for a pre-workout burn, your results might be affected by the sweat you pick up on the way. Plus, for infrared thermometers to capture accurate readings, they've got to be properly calibrated and used in a consistent manner, Advani says. Things can go wrong, for instance, if the temperature taker is standing too far or close to the patient. And no thermometer can account for the impact of fever-reducing medicine.

That said, Karan thinks "infrared thermometers have a net benefit." They're contactless and super-fast. That, plus the fact that they're reasonably accurate, despite the potential for false positives, makes them particularly attractive for pandemic use.

But that's only half the story, Advani says, pointing to a second, broader consideration: Namely, do such temperature readings really help minimize the chances that an undiagnosed patient will infect others? Here, medical professionals agree: Temperature screenings alone are an insufficient way to suss out and minimize COVID-19 risk.

"When we talk about temperature checks, we need to know what we are getting and what we are not getting," Karan says.

What we are getting, per Karan, is another layer of precaution. But it's certainly not foolproof, and alone, it's certainly not enough.

That's because of the nature of the virus: Roughly half of infections don't present with fever, Advani says. Plus, the virus can be contagious even in its presymptomatic phase — that is, before an infected person even shows signs of being sick. A nonfeverish yet contagious person could sail through a temperature check.

So despite the benefits of temperature checks — it can't hurt to turn away someone who's feverish — there is cause for skepticism. Infectious disease specialist Mark Kortepeter explains that infrared temperature screenings can contribute to a misguided sense of security, encouraging people to participate in activities that aren't altogether that safe.

Karan agrees.

"It can give people a sense of reassurance to have someone at the door scanning your head, which gives the illusion of safety," he says. "But it's not in any way guaranteeing your safety, and it's not guaranteeing you're not infectious."

Instead, temperature checks must just be one measure in an arsenal of risk prevention measures, our sources stress — including a thorough interview, asking people who they've been exposed to, if they're experiencing any of symptoms and where they've been traveling.

The take-home lesson: Individuals still need to take protective measures due to possible lapses in temperature screening. "Everything we do must be linked — that's the keystone of this," Advani says. "We want universal masking. And once you're in the business, you need to start looking at occupancy, ventilation, hand hygiene."

In stores, Kortepeter says it's a good idea to see what steps are being taken to minimize crowding. And at restaurants, Karan says you should consider points such as: Has indoor dining been moved outdoors, where the risk of transmission is lessened by air flow?

Finally, it's important to think about your own risk factors.

The elderly have a lower threshold for fever (while a 99-degree temperature may be within the normal range for the average individual, it may be cause for worry in an elderly person), Advani notes, so it's important for them to be more judicious than younger people.

Meanwhile, you might also wonder: Should I buy a no-touch thermometer for home use?

It's probably easier to use a digital thermometer or an infrared thermometer that goes in your ear, especially since thermometer guns may be hard for the untrained to administer properly. The one exception, Advani says, is for parents of young kids: Traditional thermometers can be challenging to use on a fidgety or sensitive kids. In these cases, the no-touch device may prove useful.
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Re: "Weekly Coronavirus Questions"

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Will COVID-19 become a seasonal virus?

10/5/20

https://www.news-medical.net/news/20201 ... virus.aspx

In this News-Medical interview, Dr. Hadi Yassine and Dr. Hassan Zaraket speak about their research efforts during the COVID-19 pandemic, and their research into whether COVID-19 will become a seasonal virus.

What provoked your research into the current COVID-19 pandemic?


The question of whether COVID-19 will become seasonal and just wane in summer has been of interest since the beginning of the pandemic.

Therefore, we decided to review the current knowledge on seasonality of respiratory viruses including common cold coronaviruses as well as drivers of seasonality and build on that evidence to project whether COVID-19 will follow suit of other seasonal respiratory viruses.

Can you describe what is meant by a ‘seasonal virus’ and what are the common seasonal patterns observed?

Seasonal viruses are those viruses that tend to circulate and peak during specific seasons (months) in the year.

Respiratory viruses such as influenza, respiratory syncytial viruses, and common cold coronaviruses are known to spread and peak during cold months in countries with a temperate climate.

Why do respiratory viruses follow seasonal patterns in temperate regions but not in tropical regions?


This is not fully understood. Many factors affect seasonality including host susceptibility and behavior, and virus stability. Although respiratory viruses tend to circulate year-around in tropical regions, the peak activity is usually associated with the rainy season.

Research has shown that for instance for influenza viruses low and high humidity promotes viral transmission, while moderate humidity does not promote transmissibility. It is worth noting here that transmission could be either by direct contact with infected persons/contaminated objects or airborne. These modes of transmissions are determined by temperature and humidity.

For example, higher relative humidity will result in the formation of a large viral particle, which settles down on surfaces much faster, and hence, transmission occurs mostly through direct contact of contaminated surfaces. This could be one reason for the different seasonal patterns of respiratory viruses observed in tropical and temperate regions.

How did you carry out your research into SARS-CoV-2 potentially becoming a seasonal virus? What did your results show?

We reviewed existing knowledge on the seasonality of respiratory viruses and the current knowledge about SARS-CoV-2.

We hypothesized that COVID-19 will continue to circulate year-round until herd immunity is achieved.

In your research you stated that COVID-19 could become a seasonal virus but only when herd immunity is reached. Why is this?

As population immunity builds up, the transmission rate of the virus will drop making it more susceptible to environmental factors that govern seasonality.

How could herd immunity be reached for SARS-CoV-2?

Ideally, vaccination and natural infections and cross-immunity with common cold coronaviruses can also contribute to reaching herd immunity.

Why is it so critical that public health measures are introduced to help control the virus?

The majority of populations are still susceptible to the infection. With the absence of effective vaccines and antivirals drugs, public health measures remain the only way to mitigate the pandemic.

We have seen a tremendous rise in cases in many countries after the ease of restrictions.

Do you believe that if strong public health measures are introduced, we could potentially manage the virus and prevent it from becoming a seasonal respiratory virus?

It is difficult to say. Public health measures reduce COVID-19 transmission anyway, so it will be difficult to tell whether the reduction in virus activity is affected also by seasonal factors. Since 2000, four new coronaviruses appeared in the human population: one was controlled in about two years (SARS-Cov-1; 2002-2004), two became seasonal (HKU1 and NL63; 2005-ongoing), and one still causing sporadic cases, mostly in the Gulf States (MERS-CoV; 2012-ongoing).

On the other hand, we experienced rapid and worldwide spread of SARS-CoV-2. We expect the virus to continue to spread until herd immunity is achieved and mostly become seasonal like HKU1 and NL63.

On a related subject, FLU viruses have shown diminished circulation in most countries, even after the start of the fall season. This could be partially attributed to the social measures being applied (no big gathering, no schools, etc) in the community that have some level of immunity to the virus.

What are the next steps in your research into COVID-19 and viruses?

We will be monitoring respiratory viral infection including COVID-19 to determine any potential interferences among them.

We will also monitor changes in the SARS-CoV-2 that might lead to evading the immune response.

Where can readers find more information?

https://www.frontiersin.org/articles/10 ... 67184/full
trader32176
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Re: "Weekly Coronavirus Questions"

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Coronavirus FAQ: What's The Deal With The '15 Minute Rule'?

10/9/20

https://www.npr.org/sections/goatsandso ... inute-rule


Each week, we answer "frequently asked questions" about life during the coronavirus crisis. If you have a question you'd like us to consider for a future post, email us at goatsandsoda@npr.org with the subject line: "Weekly Coronavirus Questions."

How long do you need to be exposed to someone with COVID-19 before you are at risk for being infected?

The question was brought to the forefront this week after the White House announced it would only perform contact tracing for people who had spent more than 15 minutes within 6 feet of President Trump, who tested positive for the coronavirus on Oct. 1. That "15-minute rule" is the Centers for Disease Control and Prevention's guideline for defining a close contact of an infected person.

But experts say the risk of infection is a lot more nuanced than that guidance might imply.

The 15-minute rule does not necessarily put you at zero risk if your exposure to an infected person was of a shorter duration. "It doesn't mean that you're getting off scot-free, nor does the '6-foot rule,' " says Dr. Joshua Barocas, an infectious disease specialist at Boston University School of Medicine.

"There is no magic number when it comes to distance or duration," says Emily Gurley, an epidemiologist and contact-tracing expert at the Johns Hopkins Bloomberg School of Public Health.

The coronavirus spreads when an infected person releases infectious particles while talking, coughing, singing, sneezing or even just breathing. Some of these particles are released as droplets, which generally fall to the ground within a few feet of the person who exhaled them. That's where the 6-foot guideline comes from – though it's just a guideline, not a shield of impenetrability.

A person can also expel infectious droplets in smaller particles that linger in the air for minutes or even hours and travel farther than 6 feet in a room, Barocas notes. In a poorly ventilated, enclosed space, these smaller particles can build up over time. If you're in a crowded room with lots of unmasked people talking, "whether you're [in contact for] 15 minutes or within 6 feet, it may not actually be that important anymore because there's so much virus in the air," Barocas says.

Gurley says in some jurisdictions, contact tracers also look for so-called proximate contacts – people who were in an enclosed room with an infected person at greater than 6 feet from the infected person – though they aren't considered close contacts under CDC guidance.

So where did that 15-minute part of the guideline come from? Gurley says it's based on earlier data from China on who was being infected and how infections occurred. "Even when they found lots and lots of very casual, quick contacts, that's not where they saw evidence of transmission," she says.

Instead, she says, infections were occurring when people had "meaningful" amounts of close contact – such as traveling, dining or living together – that had a higher probability of resulting in transmission. She says the 15-minute guideline is a way to help contact tracers quantify which types of interactions were long enough to be meaningful in this context.

But again, it's just a guideline, not a hard and fast rule. "We don't have strong evidence for exactly what the right distance or the right duration is, or else we'd use that," Gurley says.

And lots of variables can affect the risk of infection from close interactions, experts say.

"Certainly, if you're in very close contact with somebody who's shedding a lot of virus, and you happen to get a droplet on your hand and then wipe your nose, that could take far less than 15 minutes" to infect you, says Angela Rasmussen, a virologist at Columbia University Mailman School of Public Health.

How you interacted also matters a great deal, Barocas says. For example, was the infected person coughing? Was the person wearing a mask, which can help contain a lot of the infectious particles someone might be breathing out? Were you indoors or outdoors, where airflow would quickly disperse any infectious particles the person might have exhaled? How infectious was the person at the time of interaction? (Studies have shown that people with the coronavirus are most infectious just before and in the first few days after they start to show symptoms.) If an infected person were to cough on you while walking past, that would constitute a high-risk interaction – even if it was brief, he says.

"All of those [factors] go into what I would think of as a combined likelihood or combined probability" of getting infected, Barocas says.

Conversely, not every type of lengthy interaction is equally risky, he says. Talking outdoors on the beach on a windy day for longer than 15 minutes with someone who is asymptomatic at the time is going to be less of a risk, he says.

While indoor settings are generally higher risk than outdoor ones, the context is key, Rasmussen says. An indoor bar where people are drinking, which requires unmasking, and possibly shouting to be heard over loud music (thus emitting more particles as they talk) is going to be riskier than a trip to a hair salon where everyone is masked and only a limited number of clients are in the room at the same time.

"I finally got my first pandemic haircut a couple of weeks ago," Rasmussen notes. "And I was there for two hours." But she wouldn't dine indoors, she says, because you can't eat while wearing a mask.

Rasmussen says because so many variables can influence the risk of transmission, it's important to focus on doing all the things we know can reduce our risk of infection – wearing a mask, washing your hands, keeping your distance, trying to keep interactions outdoors as much as possible, avoiding crowds and poorly ventilated spaces. You might not always be able to do all of these things all of the time, she says – but the more of them you can do at once, the more you'll reduce your risk of infection.
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TimGDixon
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Re: "Weekly Coronavirus Questions"

Post by TimGDixon »

The bottomline friends - everyone is going to end up with antibodies to Sars/CoV2 either through vaccination, infection, or the slow immunity of corona cross-over and "human contact". Vaccines speed up the process obviously - but so do therapeutics - the endpoint is the same - antibodies must be developed in the human one way or the other. Thanks for all the hard work you are putting in giving us lots of stuff to think about.
trader32176
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Re: "Weekly Coronavirus Questions"

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you're welcome !
trader32176
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Re: "Weekly Coronavirus Questions"

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Why don't you need a negative coronavirus test to leave isolation?

10/11/20


https://www.cnn.com/2020/10/11/health/c ... index.html

President Donald Trump's doctor on Saturday said Trump has met criteria from the US Centers for Disease Control and Prevention to leave isolation after falling sick with the coronavirus.
The White House didn't say Trump had actually tested negative for the virus -- but according to CDC guidelines, people don't generally need a negative test to be around people again.
Here's why:

People can test positive even if no longer infectious

Earlier in the pandemic, health officials said people should have two negative tests for coronavirus -- taken 24 hours apart -- before being around people again. That forced some people into isolation for weeks on end.

But coronavirus tests can't necessarily determine whether someone is infectious. PCR tests, for example, just look for pieces of genetic material called RNA -- and that can linger long after someone has recovered.
According to the CDC, research has shown that people aren't likely to be infectious 10 to 20 days after symptoms first began, regardless of test results.
To figure that out, scientists have taken samples from coronavirus patients and tried to infect living cells. Even though PCR tests can come back positive, people don't tend to be infectious after that 10- to 20-day window has passed.
Think of it this way: A PCR test is looking for the blueprint of the virus -- its "genome" -- and not for the virus itself. In fact, the test is just looking for fragments of that blueprint.
It's like a recipe for chocolate cake; finding the recipe in someone's kitchen doesn't mean you'll find a cake.

Why might Trump not need to isolate for 20 days?

People with mild to moderate Covid-19 are thought to remain infectious "no longer than 10 days after symptom onset," according to the CDC, although people with severely weakened immune systems may need to isolate for longer.
Before leaving isolation, people's symptoms should have improved and they should have gone 24 hours with no fever, the CDC says (still being on fever-reducing medication doesn't count).
For patients with severe Covid-19, the CDC says up to 20 days of isolation "may be warranted." But the agency's recommendations only require 10 days. "Consider consultation with infection control experts," the CDC's recommendations say.

The President's physician, Dr. Sean Conley, released a memo Saturday that referenced "advanced diagnostic tests" and stated "there is no longer evidence of actively replicating virus" from Trump.
Still, the letter didn't fully describe those advanced diagnostic tests or their exact findings.
The President's doctor said Trump had undetectable "subgenomic mRNA." Those are molecules produced when viruses replicate. Their absence may suggest Trump is no longer shedding live virus.

But Conley did not detail what "advanced diagnostic tests" the President had received. For example, he did not say whether so-called viral culture was performed. That's the process by which scientists try to infect living cells to see whether active virus is present.
Conley also didn't disclose other vital signs from the President, such as his current oxygen levels -- leaving many questions about Trump's current condition unanswered.
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Re: "Weekly Coronavirus Questions"

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Coronavirus FAQs: Open Windows In Winter, Holding Your Breath, Sprayed Masks?

October 16, 20206:39 PM ET


I live in a cold (North Dakota) climate and will very soon have to give up outdoor socializing. If I want to try indoor socializing it'll be too cold to keep windows wide open for a long stretch. Would it help to open a window or door for a minute or two every so often?

Brr! Around the country, as colder temperatures set in, outdoor social gatherings can be harder to swing. Even our dearest friends would find it hard to join us on a snowy, windy backyard picnic or around-the-block stroll.

So from a comfort perspective, it makes sense to consider moving social activities indoors. But you're definitely incurring more risk: The outdoor air can disrupt potentially infectious exhalations. Is there a way to use open windows and air filters and other strategies to make the indoors more like the outdoors?

Before you go down that road, Sonali Advani, an assistant professor of medicine at Duke University, warns that there are limitations to focusing on ventilation via open windows as a way to prevent transmission.

"Ventilation is one of the many interventions we recommend," she says. "All of these measures, from masks to social distancing, work together in symphony. Relying on one alone will inevitably cause gaps in protection."

Those latter two measures — masks and distancing — are probably more important than just ventilation alone, Advani explains. So the best way to minimize risk is to mask up and stay six feet apart.

If you do end up meeting friends indoors — and Advani says you should seriously think about that decision because of the heightened risks of transmission associated with inside spaces — she's not sure how meaningful opening the windows for a short spell every 15-20 minutes would be when it comes to reducing risk. The total effect, she says, would likely be marginal.

Ventilation itself is only really helpful, she argues, when it's highly robust — windows open on both sides of a room to allow for cross-ventilation and an open, airy space with very few people, for example. Most people can't guarantee that at home. "When we talk about ventilation, what we really care about is air exchanges" or the number of times that air gets replaced in each room every hour. That can be accomplished with a robust air handling system — think airplanes and properly outfitted buildings. But, she says, "there's no controlled way of doing that when opening a window."

Stephen Morse, an epidemiology professor at Columbia University, agrees— but adds that some ventilation is probably "better than none." So if you feel inclined to blast open a window in the middle of your North Dakota weather, go for it. Just do so while understanding the severe limitations.

And those limitations? Well, as Morse explains, there are potentially lots of them. For instance: "You can't really tell if the virus is in the air just at the moment when the window is not open — in which case, you haven't gotten much benefit."

Plus, since there's little to no data on this, Morse says it can be hard for experts to give a definitive answer on risk.

"Opening windows and doors intermittently may have some effect on helping with creating more air flow, but the specifics of each room and situation would be different," Harvard Medical School physician Abraar Karan says.

But one thing is clear, Morse says: "If people are willing to wear masks and commit to social distancing [inside], that will help quite a bit — even [indoors with windows closed] in cold weather."

Does holding your breath while walking by an unmasked (or masked) person help reduce the odds of transmission?

It's every pandemic precautionist's worst nightmare. You've followed all the rules — siloing yourself to your house or apartment and leaving only for a CDC-approved walk around the block.

But what if an unmasked person passes by? And stops to ask you a question?


What if that person is infected and expelling viral particles? Would holding your breath prevent you from inhaling any potentially infectious bits?


Chances are — sorry to report — probably not to a great extent.

To begin with, the chances of transmission from a mini-encounter like the one above are rather small, Sonali Advani of Duke University explains. Especially if you're outdoors and you don't stop to speak with the person you're passing.

"Transmission is unlikely to happen in seconds so [holding your breath] likely won't make a difference," Abraar Karan of Harvard says. "If someone just sneezed in front of you, I wouldn't recommend inhaling that — but generally we believe it takes several minutes at least for transmission to occur."

Advani recommends carrying a mask with you to pop on in case a situation like this occurs.

Would spraying some kind of oil — like WD-40 or a silicone or lube-type spray — on the outside of my mask help trap viral particles better?

When it comes to DIY-upgrades on COVID-19 face masks, our sources are skeptical.

For one, Sonali Advani of Duke University worries about the impact that rubbing such an oil would have on filtration efficiency — the main purpose of a good mask. And there might even be added risks.

"Oil may cause bacteria to grow and affect the filtration process of the mask" she says. "That might possibly increase the risk of bacterial infection."

In general, our sources stress that people should stick to the basics of COVID-19 protection and try not to get too fancy with it.

"The virus itself largely travels within droplets or aerosol particles. Using an oil coating on a mask has not been studied in this manner to have any effect. Altering mask materials could negate efficacy," says Harvard's Abraar Karan.

He concludes, "I wouldn't put an oil coating on a mask."
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