the staff of the Ridgewood blog
Ridgewood NJ, according to Johns Hopkins Center for Health Security, the CDC published new guidance on the potential for airborne transmission of SARS-CoV-2 earlier this week. The updated guidance distinguishes between droplet and airborne transmission (as well as contact transmission); however, it emphasizes that respiratory droplets exist in a spectrum of sizes, ranging from large droplets “that fall out of the air rapidly” to smaller droplets or particles “that can remain suspended for many minutes to hours and travel far from the source.” The guidance also describes aerosols—referring both to smaller droplets and particles and the “clouds of these respiratory droplets in the air”—and clarifies the public health definition of “airborne transmission”—specifically, transmission via “infectious, pathogen-containing, small droplets and particles suspended in the air over long distances and that persist in the air for long times.”
The guidance goes on to state that most SARS-CoV-2 infections are principally spread through “close contact,” primarily through respiratory droplet transmission within a short range of 6 feet or less, rather than airborne transmission. The guidance highlights certain conditions that can facilitate airborne transmission—including enclosed spaces, inadequate ventilation, and prolonged exposure (e.g., greater than 30 minutes)—due to the accumulation of suspended respiratory droplets that could increase exposure. The CDC emphasizes that certain protective measures can mitigate airborne transmission risk in enclosed spaces, such as increased ventilation, avoiding crowded indoor spaces, mask use, and enhanced hand hygiene and disinfection practices.