8-year-old boy dies of bullet injuries during New Year's eve bash

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.

Follow latest updates on the Covid-19 pandemic here

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, July 4: India on Friday reported its highest single-day spike of COVID-19 cases with 22,771 cases reported in the last 24 hours, said the Union Ministry of Health and Family Welfare.

With these new cases, India's coronavirus cases tally has gone up to 6,48,315, out of which there are 2,35,433 active cases in the country and 3,94,227 cases have been cured/discharged or migrated.

As many as 442 deaths due to COVID-19 have been reported in the last 24 hours taking the number of patients succumbing to the deadly virus across the country to 18,655.

As per the Union Health Ministry, Maharashtra -- the worst affected state due to COVID-19 -- has a total of 1,92,990 cases which is inclusive of 8,376 deaths. Meanwhile, Tamil Nadu, the second worst-affected state, has a total of 1,02,721 cases and 1,385 fatalities. Delhi's tally of coronavirus cases stands at 94,695 which is inclusive of 2923 deaths due to the virus.

The Centre said that the recovery rate has further improved to 60.80 per cent. The recoveries/deaths ratio is 95.48 per cent : 4.52 per cent.

The Indian Council of Medical Research, earlier on Saturday, said that the total number of samples tested up to July 3 is 95,40,132, out of which 2,42,383 samples were tested yesterday.

May 28: Abdul Kareem was forced out of school and into a life of odd jobs like repairing bicycles before he finally managed to pull his family out of abject poverty transporting goods across Delhi in a mini truck.

The job, and the slim financial security that came with it, was the first stepping stone to a better life.

All that is now gone as India reels under the economic impact of its protracted coronavirus lockdown. Mr Kareem's out of a job and stranded in his village in Uttar Pradesh with his wife and two children. Their minuscule savings from his Rs 9,000 a month job have been exhausted, and the money he saved for books and school uniforms is spent.

"I don't know what the job situation will be in Delhi once we go back," Mr Kareem said. "We can't stay hungry so I will do whatever I find."

At least 49 million people across the world are expected to plunge into "extreme poverty" -- those living on less than $1.90 per day -- as a direct result of the pandemic's economic destruction and India leads that projection, with the World Bank estimating some 12 million of its citizens will be pushed to the very margins this year.

Some 122 million Indians were forced out of jobs last month alone, according to estimates from the Center for Monitoring Indian Economy, a private sector think tank. Daily wage workers and those employed by small businesses have taken the worst hit. These include hawkers, roadside vendors, workers employed in the construction industry and many who eke out a living by pushing handcarts and rickshaws.

For Prime Minister Narendra Modi, who came to power in 2014 promising to lift the poorest citizens out of poverty, the fallout from the lockdown brings with it significant political risk. He won an even larger second term majority last year on the strength of his government's popular social programs that directly targeted the poor, such as the provision of cooking gas cylinders, power and public housing. The breadth and depth of this renewed economic pain will only increase the pressure on his government as it works to steer the country's economy back on track.

"Much of the Indian government's efforts to mitigate poverty over the years could be negated in a matter of just a few months," said Ashwajit Singh, managing director of IPE Global, a development sector consultancy that advises several multinational aid agencies. Noting that he did not expect unemployment rates to improve this year, Singh said: "More people could die from hunger than the virus."

Desperate Times

Mr Singh points to a United Nations University study estimating 104 million Indians could fall below the World Bank-determined poverty line of $3.2 a day for lower-middle-income countries. This will take the proportion of people living in poverty from 60% -- or 812 million currently, to 68% or 920 million -- a situation last seen in the country more than a decade ago, he said.

A World Bank report found the country had been making significant progress and was close to losing its status as the country with the most poor citizens. The impact of PM Modi's lockdown risks reversing those gains.

The World Bank and the CMIE estimates were published in late April and early May respectively. Since then the situation has only become grimmer, with harrowing images of people making desperate attempts to reach their villages, on crowded buses, the flatbeds of trucks and even on foot or on bicycles dominating media coverage.

The Rustandy Center for Social Sector Innovation at the University of Chicago Booth School of Business analyzed the unemployment data from the CMIE, collected through surveys covering about 5,800 homes across 27 states in April.

Researchers found rural areas were the hardest hit, and the economic misery was the result of the lockdown, rather than the spread of infections in the hinterland. More than 80% of households had experienced a drop income and many won't survive much longer without aid, they wrote in a report.

The government has promised cheap credit to farmers, direct transfer of money to the poor and eased access to food security programs -- but these help people who have some documentation, which many of the poorest don't. With millions of impoverished people now in transit across the country, the food security situation is dire -- news reports are emerging of people foraging through piles of rotting fruit or eating leaves.

Shattered Economy

The economy was already growing at its slowest pace in over a decade when the virus struck. The lockdown, which came into effect on March 25, has hammered it, stalling business activity and putting a lid on consumption, pushing the economy to what may be its first full-year contraction in more than four decades.

It's dire enough to warrant the country exiting its lockdown, as it has been doing incrementally since May 4, even as its infections are surging. India is now Asia's virus hotspot with infections crossing 151,000 according to data from Johns Hopkins University.

PM Modi, who has come under criticism for the pain inflicted on the poor, has said his government will spend $265 billion or about 10% of its GDP to help Asia's third-largest economy weather the pandemic's fallout. But experts say only a part of it is direct fiscal stimulus, and probably smaller than the total damage done to the economy during the lockdown period.

"What is especially worrying is the government's response," said Reetika Khera, an economics professor at the Indian Institute of Technology in Delhi. "The epidemic will magnify existing -- and already high -- inequalities in India."

Still, the economic measures aren't going to kick in for some time and industry will likely struggle to restart because of the flight of labour from industrial hubs.

And as the harsh summer unfolds more pain lies in store in the villages now dealing with returning migrant workers.

"There are no factories or industries here, there are just hills," said Surendra Hadia Damor, who had walked nearly 100 km from Ahmedabad, Gujarat, before a voluntary organisation drove him to his village in the neighboring state of Rajasthan. "We can survive for a month or two and then try and find a job nearby -- we will see what happens."