© 2021 MJH Life Sciences and Management Healthcare Executive. all rights reserved.

© 2021 MJH Life Sciences™ and managed healthcare executive. all rights reserved.

The author of the review paper in the Annals of Internal Medicine said that the traditional dividing line between droplet transmission and smaller aerosol transmission is incorrect, and infection control measures need to reflect the new understanding that respiratory viruses are contained in respiratory particles of various sizes. Transmission may be mainly in aerosols.

For many years, experts have viewed infectious respiratory pathogens in a dualistic way.

Viruses such as flu and mumps are spread by large droplets produced by coughing and sneezing, and the droplets fall to the ground relatively quickly. It is recommended that doctors, nurses and other clinicians wear masks to block droplets.

Another group of pathogens is spread by aerosols, which are tiny respiratory particles that people produce when they speak and breathe. Aerosols tend to stay in the air much longer than droplets and spread farther. Measles and tuberculosis have long been considered two examples of viruses that spread in this way. Preventive measures against aerosols include N95 masks, negative pressure chambers, ventilation and high-efficiency particulate air (HEPA) filters.

But in a comment published earlier this month in the Annals of Internal Medicine, Harvard Medical School’s professor of population medicine and infectious disease expert Michael Klompas, MD and MPH, and his colleagues believed , The division of droplets and aerosol transmission is wrong and requires retirement.

The comment believes that research on COVID-19 and the virus that causes it, SARS-CoV-2, will help reshape the understanding of the spread of respiratory viruses. People produce various breathing particles instead of droplets or aerosols. Droplets can stay in the air for a long time like aerosols. Respiratory viruses are not picky about the particle size of their free riders. Although aerosols may be the main cause of transmission, part of the reason is that people produce gas only by speaking and breathing. Sol.

Clonpass and his colleagues wrote that the controlling factor for transmission is controlled by the "infectious dose"—the amount of virus that a person is exposed to. The review stated that the infectious dose is the product of time and exposure concentration or the amount of virus in the air. Poor ventilation can accumulate virus-laden aerosols and increase exposure, thereby increasing the infection dose. Good ventilation, HEPA filters and UV disinfection can reduce the amount of viruses floating in the air. Time is a factor, because the longer a person breathes in polluted aerosol air, the greater the infection dose.

The reviewer explained that the “strength of the source”—or the virus sprayed into the air by the infected person through respiratory particles—is another factor in the complex problem.

Klompas and his colleagues-Chanu Rhee, MD, MPH and Meghan Baker, MD, Sc.D., they are at Harvard with Klompas; Donald Milton, MD, PhD, University of Maryland School of Public Health; and MBBS, University of Maryland School of Medicine , Surbhi Leekha of MPH discussed some of the impact of current understanding of the spread of respiratory viruses on infection control policies and plans.

The following is a list of potential policy responses included in the yearbook review: