Arquivo da tag: Guerras culturais

Face masks and the coronavirus: Masks probably slow the spread of covid-19 (The Economist)

Uncategorized, , , , ,

But wearing one is mainly an act of altruism

Science & technology – May 28th 2020 edition

Editor’s note: Some of our covid-19 coverage is free for readers of The Economist Today, our daily newsletter. For more stories and our pandemic tracker, see our coronavirus hub

“THIS IS A, I would say, senseless dividing line,” said Doug Burgum, governor of North Dakota, his voice catching as he talked of the rows that have broken out in his state over the wearing of face-coverings. There are similar spats elsewhere in America, for masks have become the latest aspect of the culture war that has emerged there over how to deal with covid-19. Some shops refuse entry to maskwearers and Mike DeWine, the governor of Ohio, has rescinded an order requiring people to wear them, saying that he “went too far”.

Elsewhere in the world, by contrast, there is increasing acceptance that mask-wearing is a good thing. On May 5th, for example, the Royal Society, Britain’s top science academy, concluded that masks “could be an important tool for managing community transmission”. This is not so much because they protect the wearer—the normal reason people may put them on in times of pestilence—but rather because they stop the wearer infecting others.

In this context covid-19’s particular peculiarity—that people who test positive for it often do not have symptoms—is important. Research published last month in Nature Medicine, by Xi He of Guangzhou Medical University and Eric Lau of Hong Kong University, suggests that 44% of cases are caused by transmission from people without symptoms at the time of transmission.

Taking cover

Those who do have symptoms should not, of course, be out and about at all. In their case masks are irrelevant. But to break the chain, it behoves even the symptomless to assume that they might be infected. Covid-19 is transmitted, above all, by virus-laden droplets of spit. Experiments show that face-coverings as simple as tea-towels are effective. One study found that a tea-towel worn around the face captured 60% of droplets. At 75%, a surgical mask did better, but not overwhelmingly so.

Governments are beginning to take this on board. As part of the loosening their lockdown, the Dutch are required to wear face-coverings on public transport—but not ones of medical grade, which should be reserved for professionals. This encourages people to make their own.

Neither laboratory studies nor the data on asymptomatic transmission provide watertight evidence of the efficacy of masks. That would need randomised controlled trials, in which one group wore masks and the other did not. This would be ethically tricky, since it might condemn one of the groups to a higher death rate. Hamsters, which are susceptible to covid-19, are the next best thing to people. So researchers at Hong Kong University put cages of healthy hamsters next to cages of infected ones, with a fan in between drawing air from the infected to the healthy cage. They sometimes also placed a stretched-out face mask in the air stream. With no interposed mask, two-thirds of the healthy animals were infected within a week. With a mask interposed close to the healthy hamsters (the equivalent of a healthy person wearing a mask), one-third were. With the mask close to the infected hamsters, only a sixth were.

Although scientists cannot experiment on human beings deliberately, some wonder if the world is now carrying out a natural experiment that tests the value of mask-wearing. In many East Asian countries it was common practice to sport masks, even before covid-19, to protect against respiratory diseases and pollution. A lot of people in these places therefore took immediately to wearing masks when the epidemic started. Countries that adopted masks early on did not, by and large, shut their economies down. Yet they suppressed the disease more effectively than those that locked down but did not wear masks.

There is a correlation between mask-wearing and rapid suppression of covid-19. According to Patricia Greenhalgh, professor of primary health care sciences at Oxford University, “there is not a single country in which mask wearing was introduced early and with high compliance, where the disease wasn’t quickly brought under control.” Sceptics point out that this does not prove masks work, since countries in which they are widely worn also tend to be those which have been threatened by epidemics in the past, and therefore have well-established systems of testing and contact tracing.

In the West nobody normally wears a mask, though the practice is spreading. Universal masking started in the Czech Republic after Petr Ludwig, a Czech YouTube star, posted a video on March 14th recommending the practice, and it went viral. Other social-media influencers posted pictures of themselves wearing masks. “Mask trees”, where people would hang home-made masks for others to use, sprang up on street corners. By March 19th masks were mandatory in the country. Slovakia and Slovenia followed swiftly.

The World Health Organisation has not advocated widespread mask-wearing, and has received some criticism for this. Jeremy Howard, a research scientist at the University of San Francisco and co-founder of Masks4all, a charity, says “they did a good job of recommending handwashing and social distancing, but they have been slow on masks.”

In light of all this, regulations requiring people to wear masks have spread, as an increasing number of governments view the evidence as strong enough to warrant compulsion. India now requires them to be worn in crowded public spaces, as do France, Germany, Italy and Spain. In most of the world, people either wear them in such spaces without being told to, or are required to by their governments.

Among big countries, Britain and America are outliers. In Britain the government advises people to wear masks, but to little effect. On the London Underground around a third of travellers do so. On the Paris metro where people risk a €135 fine if they fail to cover their faces, everybody does. In America the Centres for Disease Control and Prevention, which previously recommended mask-wearing only for health workers, changed its mind in early April. It now recommends that everybody should wear them in places where it is hard for people to stay far enough apart. Several states have passed regulations along those lines, as has New York City. But, as Governor Burgum noted, the rows go on.■

This article appeared in the Science & technology section of the print edition under the headline “We interrupt this transmission…”

The Coronavirus Death Count Will Be a New Battle in the Culture Wars (Gizmodo)

Uncategorized, , , , ,

Ed Cara – 10 de abril de 2020

As parts of the United States settle in for what may be the worst weeks of their local covid-19 outbreaks, a familiar refrain is sure to emerge.

Some people will complain that the death count attributed to the coronavirus is being exaggerated. Others, including researchers, have argued that covid-19 related deaths are actually being undercounted, as people die at home without being tested. Still others will point to the final death count and say that because it’s lower than X (whether that number be flu deaths, car accident deaths, or some other moving goalpost), then that means the efforts and sacrifices made for social distancing weren’t worth it—ignoring, of course, that social distancing was the reason the toll wasn’t much higher. Figuring out how deadly covid-19 truly is will take far more time to untangle than anyone would want, and no one’s likely to be fully satisfied with the answers we get.

As of April 10, there have been around 1.6 million reported cases of covid-19, the disease caused by the novel coronavirus worldwide. There have also been over 96,000 reported deaths, with over 16,000 deaths documented in the U.S. But these numbers are largely acknowledged as a very rough, possibly even misleading estimate of the problem, given the wide gaps in testing capacity across different countries and even within a country.

On the political right, many have taken to fostering conspiracy theories about these deaths. You don’t have to go far on social media to see people accusing doctors and health officials of fudging the numbers higher to make President Trump look bad or to (somehow) profit off the tragedy. Other conservative voices like the disgraced sex pest Bill O’Reilly are less paranoid but similarly dismissive, arguing that many of those who died “were on their last legs anyway.”

It’s true that older people and those with underlying health conditions are at greater risk of serious complications and death from covid-19. But the same can be said for almost every other leading cause of death, whether it’s cancer, heart attack, or diabetes. And just as living is hardly a simple affair, so too is dying. Sometimes you can point to a single factor that kills a person, but often it’s a mix of ailments, with a viral infection like covid-19 being the final shove.

The key point here is that epidemiologists and others who try to estimate how many people die from any given cause per year know the above very well. The flu, for instance, doesn’t usually kill in isolation either—it too disproportionately kills the elderly and otherwise already sick. Yet many of the same people who are now trying to downplay covid-19 deaths also argued that its early death toll wasn’t coming anywhere close to the typical seasonal flu’s annual tally (an argument meant to push back against the idea of doing anything too serious to mitigate the spread of the coronavirus).

That said, we’re much better at estimating how many deaths in the U.S. are flu-related because the influenza virus is a known entity. We have a decent sense of how many people are infected with the flu every year, how many people go to the doctor or are hospitalized, and how many people it helps kill, thanks to a well-established nationwide surveillance system. But that isn’t true for covid-19.

There’s steady evidence indicating that covid-19 cases nearly everywhere in the world are being undercounted. That’s partly because testing remains so haphazard and has inherent limitations. The most common type of covid-19 test right now, for instance, can only confirm an active infection, not whether you had a previous case (newer antibody tests can address that problem but have their own flaws). It’s also because the virus infects a still-unknown percentage of people without making them feel sick at all.

Many more people have had or will catch the coronavirus than any current tracking will ever indicate. These hidden cases are almost certainly less deadly on average than the known cases that wind up in hospitals, so it’s likely that the current documented fatality rate of covid-19 (over 5 percent worldwide) is an overestimate. But that doesn’t mean more people aren’t dying from covid-19 than are being reported.

In areas of China and Italy hit hard by the coronavirus, news reports have suggested a wide gulf between the official number of covid-19-related deaths in a town and what residents are seeing for themselves. In the U.S., there are still regions where testing is limited and people who may have died from covid-19 in their homes are never tested, including New York City. And there’s the simple harsh reality that we’re probably still in the very beginning of this pandemic.

Even if outbreaks start to peter out in the U.S. and elsewhere, there’s the risk that loosening our restrictions on distancing will fuel new ones. And even if the summer heat in the U.S. makes it harder for the virus to spread here, as some experts hope, a second wave in the fall and winter could certainly happen, much as it did for the last pandemic (a strain of flu) in 2009.

All of these variables will affect the final death toll from covid-19, as will how countries continue to respond to the crisis. Ironically, the steps we take to prevent new cases and deaths may be the very thing that makes people doubt they were necessary.

In late March, the White House and U.S. public health officials announced that they projected 100,000 to 200,000 deaths in the country by the pandemic’s end, provided everything was done to slow its spread. On Thursday, Anthony Fauci, director of the National Institute of Allergy and Infectious Diseases, said that newer modeling data has suggested the U.S. death toll may end up closer to 60,000, so long as we keep mitigating the outbreak. Almost immediately, some people chose to take it as evidence that mitigation efforts aren’t necessary and that the initial warnings about the virus were overblown—ignoring, again, that the reason for the downward revision in projected deaths is the success of social distancing.

There are still a lot of things we don’t know about the coronavirus, and many of the things we think we know are going to keep changing. But here’s something to remember.

By the end of the 2009 H1N1 flu pandemic, the World Health Organization reported that about 19,000 people were confirmed to have died from the virus. By 2013, several studies estimated that the true death toll was at least 10 times higher and even higher still when you took into account other causes of death indirectly worsened by the flu, like heart attacks. Knowing how deadly covid-19 will be could very well take that long to nail down too.

Another article of interest:

New York City’s covid-19 death toll is likely higher than reported, due to the fact that the…Read more