News: Potential implications for reducing transmission of COVID-19

A new article by a faculty member at MIT and IMES holds promise for the prevention of and precautions around COVID-19

Lydia Bourouiba, Esther and Harold E. Edgerton Career Development Professor, MIT and associate professor, Department of Civil and Environmental Engineering, MIT and the MIT Institute for Medical Engineering and Science (IMES), suggests a new model for respiratory disease transmission in a recent article published in JAMA. The model could have implications for reducing the transmission of COVID-19.

Bourouiba’s research reveals that the current advice that people should keep to a distance of six feet apart, may be inadequate – that droplets can travel for as much as 27 feet and linger in the air for hours. Bourouiba posits that the current guidelines are “overly simplified” and “may limit the effectiveness of the proposed interventions” against COVID-19.

She cites a 2020 report from China that showed that “virus particles could be found in the ventilation systems in hospital rooms of patients with COVID-19.”

In her article, Bourouiba says, “For these and other reasons, wearing of appropriate personal protection equipment is vitally important for health care workers caring for patients who may be infected, even if they are farther than 6 feet away from a patient.”

According to the article, the current coronavirus disease 2019 (COVID-19) outbreak vividly demonstrates the burden that respiratory infectious diseases impose in an intimately connected world. Unprecedented containment and mitigation policies have been implemented in an effort to limit the spread of COVID-19, including travel restrictions, screening and testing of travelers, isolation and quarantine, and school closures.

A key goal of such policies is to decrease the encounters between infected individuals and susceptible individuals and decelerate the rate of transmission. Although such social distancing strategies are critical in the current time of pandemic, it may seem surprising that the current understanding of the routes of host-to-host transmission in respiratory infectious diseases are predicated on a model of disease transmission developed in the 1930s that, by modern standards, seems overly simplified. Implementing public health recommendations based on these older models may limit the effectiveness of the proposed interventions.

To read the full article: https://jamanetwork.com/journals/jama/fullarticle/2763852

Recent work has demonstrated that exhalations, sneezes, and coughs comprise a multiphase turbulent gas (puff) cloud of exhaled air that entrains ambient air and traps and carries within it clusters of mucosalivary fluid droplets with a continuum of droplet sizes. The droplets of all sizes are created both within and outside of the respiratory tract. This video demonstrates the phenomena in a human sneeze:

https://edhub.ama-assn.org/jn-learning/video-player/18357411

* Article and video originally published on Jama Network: https://jamanetwork.com/