COVID-19 can possibly spread through airborne aerosols, definitely via people without symptoms, WHO says


The World Health Organization updated its findings Thursday on how COVID-19 is transmitted, and there are two important changes. First, the WHO acknowledged growing evidence the new coronavirus may spread through aerosols, tiny droplets of saliva that linger in the air for hours, especially in enclosed and poorly ventilated spaces. The second change involved the risk of transmission by people who don't have symptoms. Both issues have broad implications for how to contain the disease.
The WHO maintains that the main route of transmission involves infected people projecting saliva droplets into the eyes, mouth, or nose of people in close proximity, via coughing, sneezing, talking, or singing. The agency also said spread through infected surfaces, or formite transmission, is "likely" though not yet proven. Urine and feces have been shown to contain viable amount of the new coronavirus, too.
The virus can be spread by people who don't have COVID-19 symptoms, the WHO said, but there is an "important" distinction between people who never develop symptoms (asymptomatic) and those who have yet to develop symptoms (presymptomatic), and "the extent of truly asymptomatic infection in the community remains unknown." As a practical matter, Michael Barbaro noted on Thursday's The Daily podcast, the WHO is "making distinctions that don't mean all that much to people who are trying to decide whether to go to work, whether to go to a restaurant, whether to see friends."
Subscribe to The Week
Escape your echo chamber. Get the facts behind the news, plus analysis from multiple perspectives.

Sign up for The Week's Free Newsletters
From our morning news briefing to a weekly Good News Newsletter, get the best of The Week delivered directly to your inbox.
From our morning news briefing to a weekly Good News Newsletter, get the best of The Week delivered directly to your inbox.
The WHO has long dismissed aerosols as a means of transmission except during certain medical procedures, but it now says airborne spread "cannot be ruled out." There's evidence aerosols may have been responsible for "outbreaks of COVID-19 reported in some closed settings, such as restaurants, nightclubs, places of worship, or places of work where people may be shouting, talking, or singing," the WHO said, though larger droplets or contaminated surfaces might also have caused those outbreaks.
"Outdoors, any virus in small or large droplets may be diluted too quickly in the air to pose a risk," The New York Times reports. "But even a small possibility of airborne spread indoors has enormous implications for how people should protect themselves." The new brief mostly shows the WHO's experts interpret the data on aerosols differently, Oxford University's Dr. Trish Greenhalgh tells the Times. "The push-pull of that committee is palpable," she said. "As everyone knows, if you ask a committee to design a horse, you get a camel."
A free daily email with the biggest news stories of the day – and the best features from TheWeek.com
Peter has worked as a news and culture writer and editor at The Week since the site's launch in 2008. He covers politics, world affairs, religion and cultural currents. His journalism career began as a copy editor at a financial newswire and has included editorial positions at The New York Times Magazine, Facts on File, and Oregon State University.
-
7 places across the country to experience the best of summer drinking
The Week Recommends Stops include a Basque-inspired spot and a bar where the menu overhauls twice a year
-
Amazon's robotaxi looks to be Waymo's biggest competitor
In the Spotlight The company recently opened a new robotaxi production plant in California
-
Thunder beat Pacers to clinch NBA Finals
Speed Read Oklahoma City Thunder beat the Indiana Pacers in Game 7 of the NBA Finals
-
Economists fear US inflation data less reliable
speed read The Labor Department is collecting less data for its consumer price index due to staffing shortages
-
Crypto firm Coinbase hacked, faces SEC scrutiny
Speed Read The Securities and Exchange Commission has also been investigating whether Coinbase misstated its user numbers in past disclosures
-
Starbucks baristas strike over dress code
speed read The new uniform 'puts the burden on baristas' to buy new clothes, said a Starbucks Workers United union delegate
-
Warren Buffet announces surprise retirement
speed read At the annual meeting of Berkshire Hathaway, the billionaire investor named Vice Chairman Greg Abel his replacement
-
Trump calls Amazon's Bezos over tariff display
Speed Read The president was not happy with reports that Amazon would list the added cost from tariffs alongside product prices
-
Markets notch worst quarter in years as new tariffs loom
Speed Read The S&P 500 is on track for its worst month since 2022 as investors brace for Trump's tariffs
-
Tesla Cybertrucks recalled over dislodging panels
Speed Read Almost every Cybertruck in the US has been recalled over a stainless steel panel that could fall off
-
Crafting emporium Joann is going out of business
Speed Read The 82-year-old fabric and crafts store will be closing all 800 of its stores