“We are getting surprises all the time,” said Dr. Conly. “This article seems interesting to me, but I have a lot of time left to get into a line of credibility, in my opinion.”
Dr. George Rutherford, a professor of epidemiology at the University of California, San Francisco, was equally skeptical. Outside of hospital settings, he said, “Big drops in my mind account for the vast majority of cases. Aerosol transmission: If it really works with that, it creates a lot of dissonance. Are there situations where it could happen? Yes, maybe , but it is a small amount “.
Dr. Tang and other scientists strongly disagree. “If I talk to an infectious person for 15 or 20 minutes and inhale some of their air,” said Dr. Tang, “isn’t that a much easier way to explain transmission than to touch an infected surface and touch the eyes? When talking about an outbreak, like in a restaurant, the latter seems like a devious way to explain the transmission. “
The coronavirus outbreak>
Frequent questions
Updated July 27, 2020
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Should I refinance my mortgage?
- It could be a good idea, because mortgage rates have never been lower. Refinancing applications have taken mortgage applications to some of the highest levels since 2008, so be ready to get online. But the defaults have increased, too, so if you’re thinking about buying a home, be aware that some lenders have tightened their standards.
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What will school be like in September?
- Many schools are unlikely to return to normal hours this fall, requiring the routine of online learning, impromptu child care, and delayed work days to continue. California’s two largest public school districts, Los Angeles and San Diego, said July 13 that instruction will be remote only in the fall, citing concerns that rising coronavirus infections in their areas pose too serious a risk to students and teachers. Together, the two districts enroll about 825,000 students. They are the largest in the country so far to abandon plans for a partial physical return to classrooms when they reopen in August. For other districts, the solution will not be an all-or-nothing approach. Many systems, including the country’s largest New York City, are developing hybrid plans that involve spending a few days in classrooms and other days online. There is no national policy on this yet, so check with your municipal school system regularly to see what’s going on in your community.
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Is the coronavirus in the air?
- Coronavirus can remain in the air for hours in tiny droplets in stagnant air, infecting people as they inhale, growing scientific evidence suggests. This risk is highest in crowded interior spaces with poor ventilation, and may help explain overcast events reported in meat packing plants, churches, and restaurants. It is unclear how often the virus is transmitted through these small droplets or sprays, compared to the larger droplets that are expelled when a sick person coughs or sneezes, or is transmitted through contact with contaminated surfaces, Linsey said. Marr, Virginia Tech aerosol expert. Aerosols are released even when a symptom-free person exhales, speaks or sings, according to Dr. Marr and more than 200 other experts, who have summarized the evidence in an open letter to the World Organization. Of the health.
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What are the symptoms of coronavirus?
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Does Covid-19 transmit asymptomatic?
- So far, the evidence seems to show that it does. A widely cited article published in April suggests that people are most infectious approximately two days before the onset of coronavirus symptoms, and estimated that 44 percent of new infections were the result of transmission from people who still had no symptoms. Recently, a senior expert from the World Health Organization stated that transmission of the coronavirus by people without symptoms was “very rare,” but later withdrew that claim.
In the new analysis, a team led by Parham Azimi, an indoor air researcher at Harvard’s TH Chan School of Public Health, studied the outbreak at Princess Diamond, where physical spaces and infections were well documented. He ran more than 20,000 simulations of how the virus could have spread throughout the ship. Each simulation made a variety of assumptions, about factors such as patterns of social interaction (how long people spent in their cabins, on the terrace, or in the cafeteria, on average) and the amount of time the virus can live on surfaces. Each also factored into variable contributions of smaller floating droplets, broadly defined as 10 microns or smaller; and larger drops, which fall more quickly and infect surfaces or other people, by landing on your eyes, mouth or nose, for example.
Around 130 of those simulations replicated, to some extent, what actually happened on Princess Diamond as the outbreak progressed. By analyzing these more “realistic” scenarios, the research team calculated the most likely contributions for each transmission path. The researchers concluded that the smallest drops predominated and accounted for about 60 percent of new infections overall, both at close range, within a few meters of an infectious person, and at great distances.
“Many people have argued that airborne transmission is occurring, but no one had numbers for that,” said Dr. Azimi. “What is the contribution of these little drops? Is it 5 percent or 90 percent? In this document, we provide the first real estimates of what that number might be, at least for this cruise. “
The logic behind such a transmission is straightforward, experts said. When a person speaks, he emits a cloud of drops, the vast majority of which are small enough to remain suspended in the air for a few minutes or more. Through inhalation, that cloud of small droplets is more likely to reach a mucous membrane than the larger ones that are ballistically elevated.
