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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Trump signs executive orders banning TikTok, WeChat for 45 days

Agencies
August 7,2020

Washington, Aug 7: US President Donald Trump on Thursday (local time) signed executive orders halting all transactions with Chinese applications TikTok and WeChat within 45 days, citing national security concerns, further escalating the tensions between Beijing and Washington.

"WeChat, a messaging, social media, and electronic payment application owned by the Chinese company Tencent Holdings Ltd., reportedly has over one billion users worldwide, including users in the United States. Like TikTok, WeChat automatically captures vast swaths of information from its users. 

This data collection threatens to allow the Chinese Communist Party (CCP) access to Americans' personal and proprietary information," Trump said in a statement.

Citing reasons for the ban on WeChat, the US President said that the application captures the personal and proprietary information of Chinese nationals visiting the US, thereby providing the CCP a mechanism to keep tabs on the Chinese citizens who may be "enjoying the benefits of a free society for the first time in their lives".

"In March 2019, a researcher reportedly discovered a Chinese database containing billions of WeChat messages sent from users in not only China but also the United States, Taiwan, South Korea and Australia. WeChat, like TikTok, also reportedly censors content that the CCP deems politically sensitive and may also be used for disinformation campaigns that benefit the CCP. 

These risks have led other countries, including Australia and India, to begin restricting or banning the use of WeChat. The US must take aggressive action against the owner of WeChat to protect our national security," he added.

Earlier, Trump had issued an order banning TikTok as it "reportedly censors content that the CCP deems politically sensitive, such as content concerning protests in Hong Kong and China's treatment of Uighurs and other Muslim minorities. 

TikTok may also be used for disinformation campaigns that benefit the CCP."
US politicians have repeatedly criticised TikTok, owned by Beijing-based startup ByteDance, of being a threat to national security because of its ties to China.

The development comes as China and the US are at loggerheads on a variety of issues including Hong Kong national security law, the South China Sea, the novel coronavirus and trade.

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With spike of 47,704 cases, India's COVID-19 tally reaches 14,83,157

Agencies
July 28,2020

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New Delhi, Jul 28: India on Wednesday reported 47,704 more COVID-19 cases in the last 24 hours, taking the country's count of coronavirus cases to 14,83,157, informed the Union Ministry of Health and Family Welfare.

Out of the total cases, there are 4,96,988 active cases in the country while the number of patients cured/discharged and migrated stands at 9,52,744.

With 654 deaths due to COVID-19 in the country reported in the last 24 hours, the death toll rises to 33,425.

The recovery rate among COVID-19 patients has increased to 64.23 per cent. The recoveries to deaths ratio is 96.6 per cent:3.4 per cent, informed the Centre.

As per the data provided by the Ministry, Maharashtra continues to be the worst-affected state from the infection with 1,48,905 active cases and 13,656 deaths due to COVID-19. Tamil Nadu has a total of 53,703 active cases and 3,494 deaths.

Delhi has a total of 11,904 active cases and 3,827 deaths.

The Health Ministry further informed that more than 5 lakh COVID-19 tests were conducted in a single day over two consecutive days. On 26th July, India tested a total of 5,15,000 samples and on 27th July, a total of 5,28,000 samples were tested.

The total number of COVID-19 samples tested up to July 27 is 1,73,34,885 including 5,28,082 samples tested yesterday, said the Indian Council of Medical Research (ICMR).

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Kozhikode air crash: List of deceased passengers and crew

Agencies
August 8,2020

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Kozhikode, Aug 8: The death toll in Kozhikode air crash is likely to rise as the condition of 22 injured passengers is said to be extremely critical. A total of 149 injured passengers have been admitted to hospitals in Malappuram and Kozhikode districts. 22 others have been discharged after first aid, says K Gopalakrishnan, Malappuram Collector

Deceased passengers:
Mohammed Riyas VP, 24 years - Palakkad, 
Saheer Sayed, 38 years -Malappuram, 
Lailabi KV, 51 years -Malappuram, 
Rajeevan Cherikka Parambil, 61 years - Kozhikode, 
Manal Ahamed, 25 years - Kozhikode, 
Sharafudheen, 35 years - Kozhikode, 
Janaky Kunnoth, 55 years - Kozhikode, 
Azam Muhammed Chembayi ,1 year - Kozhikode, 
Santha Marakkat, 59 years - Malappuram, 
Sudheer Vaariyath, 45 years -Malappuram, 
Sheza Fathima, 2 years -Malappuram, 
Remya Muraleedharan, 32 years - Kozhikode
Aysha Dua, 2 years – Palakkad 
Shivathmika, 5 Years- Kozhikode
Zhenobia, 40 years – Kozhikode
Sahira Banu, 29 years - Kozhikode

Deceased crew:
Deepak Sathe (Pilot)
Akhilesh Kumar (Copilot)

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