New York Times: Small Gatherings Spread the Virus, but Are They Causing the Surge?

New York Times: Small Gatherings Spread the Virus, but Are They Causing the Surge?. “Household get-togethers undoubtedly do contribute to community transmission of the virus. Canada’s recent Thanksgiving certainly added to its rising cases; such an increase may happen here, too, as the United States embarks on a holiday season like no other. That’s why the Centers for Disease Control and Prevention on Thursday warned so strongly against gathering with others outside the household during Thanksgiving. But are dinners and backyard barbecues really the engine driving the current surge of infections?”

CNN: Most coronavirus cases are spread by people without symptoms, CDC now says

CNN: Most coronavirus cases are spread by people without symptoms, CDC now says. “Most coronavirus infections are spread by people who have no symptoms, the US Centers for Disease Control and Prevention said in newly updated guidance. It’s one of the main reasons mask use is so important, the CDC said.”

New York Times: The Coronavirus Is Airborne Indoors. Why Are We Still Scrubbing Surfaces?

New York Times: The Coronavirus Is Airborne Indoors. Why Are We Still Scrubbing Surfaces?. “Scientists who initially warned about contaminated surfaces now say that the virus spreads primarily through inhaled droplets, and that there is little to no evidence that deep cleaning mitigates the threat indoors.”

Washington Post: The U.S. has absolutely no control over the coronavirus. China is on top of the tiniest risks.

Washington Post: The U.S. has absolutely no control over the coronavirus. China is on top of the tiniest risks.. “In the United States, as the pandemic rages, an increasingly pressing worry has been airborne transmission — which appears to be the key to large super-spreading events. Meanwhile, transmission from surfaces has been played down by experts, who have emphasized that this route is not thought to be a common way the virus spreads. But in China, where cases are increasingly rare and the government has adopted a no-tolerance policy for new infections, a growing emphasis has been placed on identifying less likely sources of infection.”

EurekAlert: Stanford-led team creates a computer model that can predict how COVID-19 spreads in cities

EurekAlert: Stanford-led team creates a computer model that can predict how COVID-19 spreads in cities. “The study, published today in the journal Nature, merges demographic data, epidemiological estimates and anonymous cellphone location information, and appears to confirm that most COVID-19 transmissions occur at ‘superspreader’ sites, like full-service restaurants, fitness centers and cafes, where people remain in close quarters for extended periods. The researchers say their model’s specificity could serve as a tool for officials to help minimize the spread of COVID-19 as they reopen businesses by revealing the tradeoffs between new infections and lost sales if establishments open, say, at 20 percent or 50 percent of capacity.”

New York Times: How Are Americans Catching the Virus? Increasingly, ‘They Have No Idea’

New York Times: How Are Americans Catching the Virus? Increasingly, ‘They Have No Idea’. “When the coronavirus first erupted in Sioux Falls, S.D., in the spring, Mayor Paul TenHaken arrived at work each morning with a clear mission: Stop the outbreak at the pork plant. Hundreds of employees, chopping meat shoulder to shoulder, had gotten sick in what was then the largest virus cluster in the United States. That outbreak was extinguished months ago, and these days, when he heads into City Hall, the situation is far more nebulous. The virus has spread all over town.”

A room, a bar and a classroom: how the coronavirus is spread through the air (EL PAÍS)

EL PAÍS: A room, a bar and a classroom: how the coronavirus is spread through the air. “The risk of contagion is highest in indoor spaces but can be reduced by applying all available measures to combat infection via aerosols. Here is an overview of the likelihood of infection in three everyday scenarios, based on the safety measures used and the length of exposure.”

STAT News: CDC expands definition of ‘close contacts,’ after study suggests Covid-19 can be passed in brief interactions

STAT News: CDC expands definition of ‘close contacts,’ after study suggests Covid-19 can be passed in brief interactions. “Previously, the CDC described a close contact as someone who spent 15 minutes or more within six feet of someone who was infectious. Now, the agency says it’s someone who spent a cumulative 15 minutes or more within six feet of someone who was infectious over 24 hours, even if the time isn’t consecutive, according to an agency spokesperson.”

Yale Daily News: New YSPH model helps citizens and policymakers monitor COVID-19 spread

Yale Daily News: New YSPH model helps citizens and policymakers monitor COVID-19 spread. “Researchers at the Yale School of Public Health and the T. H. Chan Harvard School of Public Health created a new tool, called covidestim, to track current COVID-19 cases on a state-by-state and county-by-county basis. The technology takes into account the latest information on the number of reported cases, death counts and disease severity to provide accurate information about the pandemic to citizens. Access to the online model is free to the general public.”

Princeton University: Research shows conversation quickly spreads droplets more than six feet inside buildings

Princeton University: Research shows conversation quickly spreads droplets more than six feet inside buildings. “With implications for the transmission of diseases like COVID-19, researchers have found that ordinary conversation creates a conical, ‘jet-like’ airflow that quickly carries a spray of tiny droplets from a speaker’s mouth across meters of an interior space.”

NPR: CDC Acknowledges Coronavirus Can Spread Via Airborne Transmission

NPR: CDC Acknowledges Coronavirus Can Spread Via Airborne Transmission. “The Centers for Disease Control and Prevention now says the coronavirus can be spread through airborne particles that can linger in the air ‘for minutes or even hours’ — even among people who are more than 6 feet apart.”

The Atlantic: This Overlooked Variable Is the Key to the Pandemic

The Atlantic: This Overlooked Variable Is the Key to the Pandemic. “By now many people have heard about R0—the basic reproductive number of a pathogen, a measure of its contagiousness on average. But unless you’ve been reading scientific journals, you’re less likely to have encountered k, the measure of its dispersion. The definition of k is a mouthful, but it’s simply a way of asking whether a virus spreads in a steady manner or in big bursts, whereby one person infects many, all at once. After nine months of collecting epidemiological data, we know that this is an overdispersed pathogen, meaning that it tends to spread in clusters, but this knowledge has not yet fully entered our way of thinking about the pandemic—or our preventive practices.”

Slate: How the 6-Feet Rule Can Lead Us Astray

Slate: How the 6-Feet Rule Can Lead Us Astray. “The original definition for close contact was basically a good guess, made at the beginning of the pandemic, with the understanding that the virus spread via relatively large particles. Helpfully, our understanding of how the virus makes its way from one person to the next has evolved since. It turns out that large virus-containing particles, the kind that usually don’t travel more than a few feet and don’t linger in the air, aren’t the only particles that an infected person expels as they breathe, talk, and cough. They also emit smaller particles that remain airborne for minutes to hours.”

Washington Post: Yes, airborne transmission is happening. The CDC needs to set the record straight.

Washington Post: Yes, airborne transmission is happening. The CDC needs to set the record straight.. “The science here is fairly straightforward. When you talk or sing — or even just breathe — you emit a range of particles of different sizes. Yes, there might be one or two particles that are large enough to see and that fall to the ground within six feet, but there are also thousands of particles that are smaller than five microns (or five millionths of a meter). Such particles stay aloft for minutes to hours and can travel all the way across a room on natural air currents. They don’t stop at six feet. They will stay in the air in the room until they are pushed outdoors by ventilation, trapped on a filter if you have one, or deposited in your lungs. More importantly, among particles that stay in the air long enough to be inhaled, those smaller than five microns actually carry more virus than the larger ones, counterintuitively.”