Cong demands PM Modi’s apology for ‘insulting’ Bengaluru

The coronavirus can stay aloft for hours in tiny droplets in stagnant air, infecting people as they inhale, mounting scientific evidence suggests.

This risk is highest in crowded indoor spaces with poor ventilation, and may help explain superspreading events reported in meatpacking plants, churches and restaurants.

It’s unclear how often the virus is spread via these tiny droplets, or aerosols, compared with larger droplets that are expelled when a sick person coughs or sneezes, or transmitted through contact with contaminated surfaces, said Linsey Marr, an aerosol expert at Virginia Tech.

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Aerosols are released even when a person without symptoms exhales, talks or sings, according to Marr and more than 200 other experts, who have outlined the evidence in an open letter to the World Health Organization.

What is clear, they said, is that people should consider minimizing time indoors with people outside their families. Schools, nursing homes and businesses should consider adding powerful new air filters and ultraviolet lights that can kill airborne viruses.

What does it mean for a virus to be airborne?

For a virus to be airborne means that it can be carried through the air in a viable form. For most pathogens, this is a yes-no scenario. HIV, too delicate to survive outside the body, is not airborne. Measles is airborne, and dangerously so: It can survive in the air for up to two hours.

For the coronavirus, the definition has been more complicated. Experts agree that the virus does not travel long distances or remain viable outdoors. But evidence suggests it can traverse the length of a room and, in one set of experimental conditions, remain viable for perhaps three hours.

How are aerosols different from droplets?

Aerosols are droplets, droplets are aerosols — they do not differ except in size. Scientists sometimes refer to droplets fewer than 5 microns in diameter as aerosols. (By comparison, a red blood cell is about 5 microns in diameter; a human hair is about 50 microns wide.)

From the start of the pandemic, the WHO and other public health organizations have focused on the virus’s ability to spread through large droplets that are expelled when a symptomatic person coughs or sneezes.

These droplets are heavy, relatively speaking, and fall quickly to the floor or onto a surface that others might touch. This is why public health agencies have recommended maintaining a distance of at least 6 feet from others, and frequent hand washing.

But some experts have said for months that infected people also are releasing aerosols when they cough and sneeze. More important, they expel aerosols even when they breathe, talk or sing, especially with some exertion.

Scientists know now that people can spread the virus even in the absence of symptoms — without coughing or sneezing — and aerosols might explain that phenomenon.

Because aerosols are smaller, they contain much less virus than droplets do. But because they are lighter, they can linger in the air for hours, especially in the absence of fresh air. In a crowded indoor space, a single infected person can release enough aerosolized virus over time to infect many people, perhaps seeding a superspreader event.

For droplets to be responsible for that kind of spread, a single person would have to be within a few feet of all the other people, or to have contaminated an object that everyone else touched. All that seems unlikely to many experts: “I have to do too many mental gymnastics to explain those other routes of transmission compared to aerosol transmission, which is much simpler,” Marr said.

Can I stop worrying about physical distancing and washing my hands?

Physical distancing is still very important. The closer you are to an infected person, the more aerosols and droplets you may be exposed to. Washing your hands often is still a good idea.

What’s new is that those two things may not be enough. “We should be placing as much emphasis on masks and ventilation as we do with hand washing,” Marr said. “As far as we can tell, this is equally important, if not more important.”

Should I begin wearing a hospital-grade mask indoors? And how long is too long to stay indoors?

Health care workers may all need to wear N95 masks, which filter out most aerosols. At the moment, they are advised to do so only when engaged in certain medical procedures that are thought to produce aerosols.

For the rest of us, cloth face masks will still greatly reduce risk, as long as most people wear them. At home, when you’re with your own family or with roommates you know to be careful, masks are still not necessary. But it is a good idea to wear them in other indoor spaces, experts said.

As for how long is safe, that is frustratingly tough to answer. A lot depends on whether the room is too crowded to allow for a safe distance from others and whether there is fresh air circulating through the room.

What does airborne transmission mean for reopening schools and colleges?

This is a matter of intense debate. Many schools are poorly ventilated and are too poorly funded to invest in new filtration systems. “There is a huge vulnerability to infection transmission via aerosols in schools,” said Don Milton, an aerosol expert at the University of Maryland.

Most children younger than 12 seem to have only mild symptoms, if any, so elementary schools may get by. “So far, we don’t have evidence that elementary schools will be a problem, but the upper grades, I think, would be more likely to be a problem,” Milton said.

College dorms and classrooms are also cause for concern.

Milton said the government should think of long-term solutions for these problems. Having public schools closed “clogs up the whole economy, and it’s a major vulnerability,” he said.

“Until we understand how this is part of our national defense, and fund it appropriately, we’re going to remain extremely vulnerable to these kinds of biological threats.”

What are some things I can do to minimize the risks?

Do as much as you can outdoors. Despite the many photos of people at beaches, even a somewhat crowded beach, especially on a breezy day, is likely to be safer than a pub or an indoor restaurant with recycled air.

But even outdoors, wear a mask if you are likely to be close to others for an extended period.

When indoors, one simple thing people can do is to “open their windows and doors whenever possible,” Marr said. You can also upgrade the filters in your home air-conditioning systems, or adjust the settings to use more outdoor air rather than recirculated air.

Public buildings and businesses may want to invest in air purifiers and ultraviolet lights that can kill the virus. Despite their reputation, elevators may not be a big risk, Milton said, compared with public bathrooms or offices with stagnant air where you may spend a long time.

If none of those things are possible, try to minimize the time you spend in an indoor space, especially without a mask. The longer you spend inside, the greater the dose of virus you might inhale.

New Delhi, Feb 24: They hail from vastly different backgrounds — Donald Trump is the son of a property tycoon while Narendra Modi is a descendant of a poor tea-seller.

Yet the two teetotallers, loved by right-wing nationalists in their home countries, share striking similarities that have seen them forge a close personal bond, analysts say.

Ahead of the American leader's first official visit to India, which begins in Modi's home state of Gujarat on Monday, the world's biggest democracy has gone out of its way to showcase the chemistry between them.

In Gujarat's capital Ahmedabad, large billboards with the words "two dynamic personalities, one momentous occasion" and "two strong nations, one great friendship" have gone up across the city.

"There's a lot that Trump and Modi share in common, and not surprisingly these convergences have translated into a warm chemistry between the two," Michael Kugelman of the Washington-based Wilson Center said.

"Personality politics are a major part of international diplomacy today. The idea of closed-door dialogue between top leaders has often taken a backseat to very public and spectacle-laden summitry."

Since assuming the top political office in their respective countries — Modi in 2014 and Trump in 2017 — the two men have been regularly compared to each other.

Trump, 73, and Modi, 69, both command crowds of adoring flag-waving supporters at rallies. A virtual cult of personality has emerged around them, with their faces and names at the centre of their political parties' campaigns.

A focus of Trump's administration has been his crackdown on migrants, including a travel ban that affects several Muslim-majority nations, among others, while critics charge that Modi has sought to differentiate Muslims from other immigrants through a contentious citizenship law that has sparked protests.

Both promote their countries' nationalist and trade protectionist movements — Trump with his "America First" clarion call and Modi with his "Make in India" mantra.

And while they head the world's largest democracies, critics have described the pair as part of a global club of strongmen that includes Russia's Vladimir Putin and Brazil's Jair Bolsonaro.

"There are many qualities that Trump and Modi share — a love for political grandstanding and an unshakable conviction that they can achieve the best solutions or deals," former Indian diplomat Rakesh Sood said.

Modi and Trump have sought to use their friendship to forge closer bonds between the two nations, even as they grapple with ongoing tensions over trade and defence.

Despite sharing many similarities in style and substance, analysts say there are some notable differences between the pair.

Modi is an insider who rose through the ranks of the Bharatiya Janata Party after starting out as a cadre in Rashtriya Swayamsevak Sangh.

Trump is a businessman and a political outsider who has in some sense taken over the Republican Party.

"Modi is a more conventional leader than is Trump in that he hasn't sought to revolutionise the office he holds in the way that Trump has," said Kugelman, a longtime observer of South Asian politics.

He added that genuine personal connections between leaders of both countries have helped to grow the partnership.

"George Bush and Manmohan Singh, Barack Obama and Singh, Obama and Modi, now Modi and Trump — there has been a strong chemistry in all these pairings that has clearly helped the relationship move forward," he added.

Trump has also stood by the Indian leader during controversial decisions, including his revocation of autonomy for Kashmir and his order for jets to enter Pakistani territory following a suicide bombing.

Analysts said the leaders would use the visit to bolster their image with voters.

A mega "Namaste Trump" rally in Ahmedabad on Monday will be modelled after the "Howdy, Modi" Houston extravaganza last year when the Indian leader visited the US and the two leaders appeared before tens of thousands of Indian-Americans at a football stadium.

"The success of this visit... will have a positive impact on his (Trump's) re-election campaign and the people of Indian origin who are voters in the US — a majority of them are from Gujarat," former Indian diplomat Surendra Kumar said.

"On the Indian side, the fact that Prime Minister Modi... (shares) such warmth, bonhomie and informality with the most powerful man on Earth adds to his stature... as well as with hardcore supporters."