The means of transmission of SARS-CoV-2 and the age group most likely to transmit the virus—people in their 20s—garnered headlines this week, as well as controversy for the CDC.
The coronavirus disease 2019 (COVID-19) pandemic has challenged us in a variety of ways. From personal protective equipment (PPE) to testing roadblocks, and the sort of persistence that exhausts us all—this has been a trying time. As the world inches closer to a year of this pandemic, what have we learned? Moreover, what are the changing and shifting perceptions of this virus and infection? Two main topics really stuck out this week—aerosols and age distribution.
Change Age Distribution of the COVID-19 Pandemic in the United States
A new Morbidity and Mortality Weekly Report (MMWR) from the US Centers for Disease Control and Prevention (CDC) evaluates a shift in the age distribution of the COVID-19 illness within the United States. Early on, those impacted by the virus were older adults, but recent months have seen a shift in terms of younger people acquiring the disease. From June through August of this year, researchers identified that the highest incidence was in those aged 20-29 years. This age group accounted for more than 20% of all confirmed cases and researchers noted that those younger adults also played a role in community transmission.
The authors noted that “the shift toward younger ages occurred in all four U.S. Census regions, regardless of changes in incidence during this period, and was reflected in COVID-19–like illness-related ED visits, positive SARS-CoV-2 RT-PCR test results, and confirmed COVID-19 cases. A similar age shift occurred in Europe, where the median age of COVID-19 cases declined from 54 years during January–May to 39 years during June–July, during which time persons aged 20–29 years constituted the largest proportion of cases (19.5%)”. Overall, this trend points to a critical need to target prevention and testing efforts within this age group and to push communication on community-based prevention strategies.
Aerosols and Droplets—A CDC Website Debacle
The CDC found itself the subject of some controversy. Last Friday, the agency posted something new on its website about COVID-19 spread but then backtracked, and the update had been taken down by Monday with the disclaimer that the new information had been “posted in error.” The communication that was withdrawn noted that transmission of the virus is through “respiratory droplets or small particles, such as those in aerosols, produced when an infected person coughs, sneezes, sings, talks, or breathes,” and that inhalation is thought to be the main way the virus spreads. Moreover, it noted that transmission can occur even if people observe the 6-foot social distancing guidance.
The posting and then withdrawing of the comments couldn’t have come at a worse time with trust in the CDC starting to ebb, but also as the community navigates the haphazard use of “airborne” by many. It has been widely known for months that close-range, small aerosols do contribute to transmission, as we’ve seen in super-spreader events and clusters related to indoor exposures despite distancing. Moreover, this guidance does require careful explanation of what it means for the community. Realistically, it will likely stay the same—masks, distancing, ventilation, cleaning/disinfection, hand hygiene, and avoiding crowded indoor environments. The challenge though is communicating that, as such terms carry weighted meanings in various fields, like healthcare and epidemiology.