The B.C. Centre for Disease Control has begun to acknowledge that small droplets can linger in enclosed areas and lead to infection.
In a tweet, the organization stated that “#COVID19 spreads from a person with COVID-19 to others through larger droplets and smaller droplets known as aerosols.”
The B.C. CDC quietly made the chance to its website Tuesday, after months of saying – along with health officials – that COVID-19 spread only through large droplets expelled when a person talks, sneezes or coughs.
According to the B.C. CDC, the smaller droplets, also known as aerosols, are lighter and can linger in the air for longer periods of time.
“Smaller droplets can collect in enclosed spaces when there is not enough fresh air. Indoor accumulation is greater when more people share a space, spend more time together, or exercise, sing, shout, or speak loudly,” the B.C. CDC website said. “These conditions can lead to COVID-19 transmission. Opening windows or increasing fresh air intake with mechanical ventilation are important protective measures that can help reduce the spread of COVID-19.”
Respiratory infections such as influenza (flu) and COVID-19 are mainly spread by liquid droplets that come out of the mouth and nose when a person with the virus breathes, coughs, sneezes, talks, or sings. Droplets come in a wide range of sizes, from smaller than the width of a hair to larger than a grain of sand. A few large droplets or many small droplets can contain enough virus to infect another person.
The change in messaging is similar to one made by the Public Health Agency of Canada in November, when it acknowledged the spread of the virus via aerosols.
The B.C. CDC also changed its wording around surfaces spreading COVID-19. In prior versions of its website, the organization said that “infection from contact with contaminated surfaces appears to be less common.” On Tuesday, that messaging was switched to “rare.”
Other changes included encoding a three-layer mask, instead of simply a mask, in guidance on how to avoid becoming infected.