Coronavirus airborne: What we should do now

International New York Times
July 7, 2020

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.

Comments

Add new comment

  • Coastaldigest.com reserves the right to delete or block any comments.
  • Coastaldigset.com is not responsible for its readers’ comments.
  • Comments that are abusive, incendiary or irrelevant are strictly prohibited.
  • Please use a genuine email ID and provide your name to avoid reject.
News Network
March 5,2020

New Delhi, Mar 5: Union Health Minister Harsh Vardhan assuring that the government has the coronavirus crisis under control, is like the Titanic captain telling passengers not to panic as his ship was unsinkable, Congress leader Rahul Gandhi said on Thursday.

Gandhi's remarks came after Vardhan's assurance in Parliament that the government is taking all necessary measures to prevent the spread of COVID-19 (coronavirus disease) in India.

“The health minister saying that the Indian government has the coronavirus crisis under control, is like the Captain of the Titanic telling passengers not to panic as his ship was unsinkable,” Gandhi said in a tweet.

“It's time the government made public an action plan backed by solid resources to tackle this crisis,” he said.

RMS Titanic was a British passenger liner that sank in the North Atlantic Ocean in the early morning hours of April 15, 1912, after striking an iceberg during her maiden voyage from Southampton to New York.

Gandhi has been raising concerns over the coronavirus infection since long. In a February 12 tweet, he had said coronavirus is an extremely serious threat to “our people and our economy”.

“My sense is the government is not taking this threat seriously. Timely action is critical,” he had said.

Earlier this week, Gandhi had hit out at Prime Minister Narendra Modi over the detection of fresh coronavirus cases in the country, saying he should quit wasting India's time “playing the clown” with his social media accounts when India is facing an emergency.

With the message of “Here's how it's done”, Gandhi had also tweeted a video of Singaporean Prime Minister Lee Hsien Loong addressing Singaporeans on how to deal with the coronavirus.

The number of coronavirus cases in India is 29, including 16 Italians, the government had said on Wednesday, adding all international passengers will now be screened at airports, amid growing concern over the spread of the respiratory infection.

Comments

Add new comment

  • Coastaldigest.com reserves the right to delete or block any comments.
  • Coastaldigset.com is not responsible for its readers’ comments.
  • Comments that are abusive, incendiary or irrelevant are strictly prohibited.
  • Please use a genuine email ID and provide your name to avoid reject.
News Network
January 13,2020

Jan 13: For the first time in years, the government of India’s Prime Minister Narendra Modi is playing defense. Protests have sprung up across the country against an amendment to India’s laws — which came into effect on Friday — that makes it easier for members of some religions to become citizens of India. The government claims this is simply an attempt to protect religious minorities in the Muslim-majority countries that border India; but protesters see it as the first step toward a formal repudiation of India’s constitutionally guaranteed secularism — and one that must be resisted.

Modi was re-elected prime minister last year with an enhanced majority; his hold over the country’s politics is absolute. The formal opposition is weak, discredited and disorganized. Yet, somehow, the anti-Citizenship Act protests have taken hold. No political party is behind them; they are generally arranged by student unions, neighborhood associations and the like.

Yet this aspect of their character is precisely what will worry Modi and his right-hand man, Home Minister Amit Shah. They know how to mock and delegitimize opposition parties with ruthless efficiency. Yet creating a narrative that paints large, flag-waving crowds as traitors is not quite that easy.

For that is how these protests look: large groups of young people, many carrying witty signs and the national flag. They meet and read the preamble to India’s Constitution, into which the promise of secularism was written in the 1970’s.

They carry photographs of the Constitution’s drafter, the Columbia University-trained economist and lawyer B. R. Ambedkar. These are not the mobs the government wanted. They hoped for angry Muslims rampaging through the streets of India’s cities, whom they could point to and say: “See? We must protect you from them.” But, in spite of sometimes brutal repression, the protests have largely been nonviolent.

One, in Shaheen Bagh in a Muslim-dominated sector of New Delhi, began simply as a set of local women in a square, armed with hot tea and blankets against the chill Delhi winter. It has now become the focal point of a very different sort of resistance than what the government expected. Nothing could cure the delusions of India’s Hindu middle class, trained to see India’s Muslims as dangerous threats, as effectively as a group of otherwise clearly apolitical women sipping sweet tea and sharing their fears and food with anyone who will listen.

Modi was re-elected less than a year ago; what could have changed in India since then? Not much, I suspect, in most places that voted for him and his party — particularly the vast rural hinterland of northern India. But urban India was also possibly never quite as content as electoral results suggested. India’s growth dipped below 5% in recent quarters; demand has crashed, and uncertainty about the future is widespread. Worse, the government’s response to the protests was clearly ill-judged. University campuses were attacked, in one case by the police and later by masked men almost certainly connected to the ruling party.

Protesters were harassed and detained with little cause. The courts seemed uninterested. And, slowly, anger began to grow on social media — not just on Twitter, but also on Instagram, previously the preserve of pretty bowls of salad. Instagram is the one social medium over which Modi’s party does not have a stranglehold; and it is where these protests, with their photogenic signs and flags, have found a natural home. As a result, people across urban India who would never previously have gone to a demonstration or a political rally have been slowly politicized.

India is, in fact, becoming more like a normal democracy. “Normal,” that is, for the 2020’s. Liberal democracies across the world are politically divided, often between more liberal urban centers and coasts, and angrier, “left-behind” hinterlands. Modi’s political secret was that he was that rare populist who could unite both the hopeful cities and the resentful countryside. Yet this once magic formula seems to have become ineffective. Five of India’s six largest cities are not ruled by Modi’s Bharatiya Janata Party in any case — the financial hub of Mumbai changed hands recently. The BJP has set its sights on winning state elections in Delhi in a few weeks. Which way the capital’s voters will go is uncertain. But that itself is revealing — last year, Modi swept all seven parliamentary seats in Delhi.

In the end, the Citizenship Amendment Act is now law, the BJP might manage to win Delhi, and the protests might die down as the days get unmanageably hot and state repression increases. But urban India has put Modi on notice. His days of being India’s unifier are over: From now on, like all the other populists, he will have to keep one eye on the streets of his country’s cities.

Comments

Add new comment

  • Coastaldigest.com reserves the right to delete or block any comments.
  • Coastaldigset.com is not responsible for its readers’ comments.
  • Comments that are abusive, incendiary or irrelevant are strictly prohibited.
  • Please use a genuine email ID and provide your name to avoid reject.
Agencies
May 14,2020

New Delhi, May 14: India may witness the death of additional 1.2-6 lakh children over the next one year from preventable causes as a consequence to the disruption in regular health services due to the COVID-19 pandemic, UNICEF has warned.

The warning comes from a new study that brackets India with nine other nations from Asia and Africa that could potentially have the largest number of additional child deaths as a consequence to the pandemic.

These potential child deaths will be in addition to the 2.5 million children who already die before their fifth birthday every six months in the 118 countries included in the study.

The estimate is based on an analysis by researchers from the Johns Hopkins Bloomberg School of Public Health published in the Lancet.  

This means the global mortality rate of children dying before their fifth birthday, one of the key progress indicators in all of the global development, could potentially increase for the first time since 1960 when the data was first collected.

There were 1.04 million under-5 deaths in India in 2017, of which nearly 50% (0.57 million) were neonatal deaths. The highest number of under-5 deaths was in Uttar Pradesh (312,800 which included 165,800 neonatal deaths) and Bihar (141,500 which included 75,300 neonatal deaths).

The researchers looked at three scenarios, factoring in parameters like reduction in workforce, supplies and access to healthcare for services like family planning, antenatal care, childbirth care, postnatal care, vaccination and preventive care for early childhood. The effects are modelled for a period of three months, six months and 12 months.  

In scenario-1 marked by 10-18% reduction of coverage of all the services, the number of additional children deaths could be in the range of 30,000 plus over three months, more than 60,000 over six months and above 120,000 over the next 12 months.

Coronavirus India update: State-wise total number of confirmed cases, deaths on May 13

The numbers sharply rose to nearly 55,000; 109,000 and 219,000 respectively for scenario-2, which was associated with an 18-28% drop in all the regular services.

But in the worst-case scenario in which 40-50% of the services are not available, the number of additional deaths ballooned to 1.5 lakhs in the three months in the short-range to nearly six lakhs over a year.

The ten countries that could potentially have the largest number of additional child deaths are Bangladesh, Brazil, Congo, Ethiopia, India, Indonesia, Nigeria, Pakistan, Uganda and Tanzania.

In countries with already weak health systems, COVID-19 is causing disruptions in medical supply chains and straining financial and human resources.

Visits to health care centres are declining due to lockdowns, curfews and transport disruptions, and due to the fear of infection among the communities. Such disruptions could result in potentially devastating increases in maternal and child deaths, the UN agency warned.

Comments

Add new comment

  • Coastaldigest.com reserves the right to delete or block any comments.
  • Coastaldigset.com is not responsible for its readers’ comments.
  • Comments that are abusive, incendiary or irrelevant are strictly prohibited.
  • Please use a genuine email ID and provide your name to avoid reject.