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.

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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.

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News Network
June 30,2020

Six months since the new coronavirus outbreak, the pandemic is still far from over, the World Health Organization said Monday, warning that "the worst is yet to come".

Reaching the half-year milestone just as the death toll surpassed 500,000 and the number of confirmed infections topped 10 million, the WHO said it was a moment to recommit to the fight to save lives.

"Six months ago, none of us could have imagined how our world -- and our lives -- would be thrown into turmoil by this new virus," WHO chief Tedros Adhanom Ghebreyesus told a virtual briefing.

"We all want this to be over. We all want to get on with our lives. But the hard reality is this is not even close to being over.

"Although many countries have made some progress, globally the pandemic is actually speeding up.

"We're all in this together, and we're all in this for the long haul.

"We will need even greater stores of resilience, patience, humility and generosity in the months ahead.

"We have already lost so much -- but we cannot lose hope."

Tedros also said that the pandemic had brought out the best and worst humanity, citing acts of kindness and solidarity, but also misinformation and the politicisation of the virus.

In an atmosphere of global political division and fractures on a national level, "the worst is yet to come. I'm sorry to say that," he said.

"With this kind of environment and condition, we fear the worst."

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News Network
May 19,2020

New Delhi, May 19: The number of coronavirus cases crossed the one lakh mark in the country on Tuesday, while the death toll due to the infection touched 3,163, according to the Union Health Ministry.

A total of 134 deaths and 4,970 COVID-19 cases were reported in the country in the past 24 hours since 8 pm on Monday, it said.

The total number of coronavirus cases has risen to 1,01,139, the ministry said.

The number of active COVID-19 cases stood at 58,802 while 39,173 people have recovered and one patient has migrated, it said.

"Thus, around 38.73 per cent patients have recovered so far," a senior health ministry official said.

The total confirmed cases include foreigners.

Of the 134 deaths reported since Monday morning, 51 were in Maharashtra, 35 in Gujarat, 14 in Uttar Pradesh, eight in Delhi, seven in Rajasthan, six in West Bengal, four in Madhya Pradesh, three in Tamil Nadu, two each in Punjab and Jammu and Kashmir, and one each in Bihar and Telangana.

Of the 3,163 fatalities, Maharashtra tops tally with 1,249 deaths. Gujarat comes second with 694 deaths, followed by Madhya Pradesh at 252, West Bengal at 244, Delhi at 168, Rajasthan at 138, Uttar Pradesh at 118, Tamil Nadu at 81 and Andhra Pradesh at 50.

The death toll reached 37 each in Karnataka and Punjab and 35 in Telangana.

Jammu and Kashmir has reported 15 fatalities due to the disease, Haryana has 14 deaths while Bihar has registered nine and Kerala and Odisha each have reported four deaths.

Jharkhand, Chandigarh and Himachal Pradesh each have recorded three COVID-19 fatalities, while Assam has reported two deaths.

 Meghalaya, Uttarakhand and Puducherry have reported one fatality each, according to the data provided by the ministry.

According to the ministry's website, more than 70 per cent of the deaths are due to comorbidities, the existence of multiple disorders in the same person.

According to the health ministry's data updated in the morning, the highest number of confirmed cases in the country are from Maharashtra at 35,058, followed by Tamil Nadu at 11,760, Gujarat at 11,745, Delhi at 10,054, Rajasthan at 5,507, Madhya Pradesh at 5,236 and Uttar Pradesh at 4,605.

The number of COVID-19 cases has gone up to 2,825 in West Bengal, 2,474 in Andhra Pradesh and 1,980 in Punjab.

It has risen to 1,597 in Telangana, 1,391 in Bihar, 1,289 in Jammu and Kashmir, 1,246 in Karnataka and 928 in Haryana.

Odisha has reported 876 coronavirus infection cases so far, while Kerala has 630 cases. A total of 223 people have been infected with the virus in Jharkhand and 196 in Chandigarh.

Tripura has reported 167 cases, Assam has 107, Uttarakhand and Chhattisgarh have 93 cases each, Himachal Pradesh has 90 and Ladakh has registered 43 cases so far.

Goa has reported 38 COVID-19 cases, while the Andaman and Nicobar Islands has registered 33 infections.

Puducherry has registered 18 cases, Meghalaya has 13 and Manipur has seven cases. Mizoram, Arunachal Pradesh and Dadar and Nagar Haveli have reported a case each till how.

"814 cases are being reassigned to states," the ministry said on its website, adding "our figures are being reconciled with the ICMR".

State-wise distribution is subject to further verification and reconciliation, it said.

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News Network
July 12,2020

New Delhi, Jul 12: With the highest single-day spike of 28,637 new cases and 551 deaths being reported in the last 24 hours, India's COVID-19 count reached 8,49,553 on Sunday.

According to the Union Health and Family Welfare Ministry, this includes 2,92,258 active cases, and 5,34,621 cured and discharged or migrated patients. The toll due to the disease has reached 22,674 in the country.

Maharashtra with 2,46,600 cases continues to be the worst affected state by COVID-19 in the country. The state has 99,499 active cases while 1,36,985 patients have been cured and discharged so far. The death toll due to the disease now stands at 10,116.

Tamil Nadu with 1,34,226 cases, including 46,413 active ones, is the next worst affected in the country. While the number of cured and discharged patients is at 85,915 in the state, the toll due to the disease is at 1,898.

The national capital has recorded 1,10,921 confirmed cases so far. However, the number of active cases in Delhi is at 19,895 and 87,692 patients have been cured and discharged so far. With 3,334 deaths being reported due to COVID-19 in the city. 

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