June 26, 2022

Medical Trend

Medical News and Medical Resources

Not only coronavirus, but other viruses can be spread through aerosols?

Not only coronavirus, but other viruses can be spread through aerosols?



Not only coronavirus, but other viruses can be spread through aerosols!

Scientists tell you: This is not only the case with the new coronavirus, but also with most other respiratory viruses!

Introduction: In recent years of the COVID-19 virus, scientists have carried out a number of studies on the COVID-19 virus. In a recent study, they not only discovered a major mode of transmission of the COVID-19 virus, but also found most of the other respiratory tracts. Viruses are spread in this same way…

As we all know, the global spread of the COVID-19 epidemic is caused by SARS-CoV-2 (new coronavirus). This virus mainly relies on inhalation of virus-carrying aerosols to spread. In this way, the virus can be transmitted at close or far distances. The range of distance spreads easily. On this basis, scientists have studied the transmission methods and characteristics of some other viruses.

They found through experiments that not only the new coronavirus is the case, but other respiratory viruses are also transmitted in this way. For example, SARS virus, MERS coronavirus, influenza virus, measles virus, and rhinovirus that causes the common cold can be spread through the above methods, and this aerosol can even accumulate in the indoor air and can last for many hours.

The results of this research were published in an article titled “Airborne transmission of respiratory viruses” in “Science” magazine:

Not only coronavirus, but other viruses can be spread through aerosols!

This research was carried out by an international interdisciplinary research team, and together they had a new understanding of the way the virus spreads. In the last century and at the beginning of the COVID-19 pandemic, it was generally believed that respiratory viruses like the COVID-19 virus were mainly transmitted through these two methods: droplets produced when the infected person coughed and sneezed to other people, Infect the virus by touching a surface contaminated with the virus.

However, neither droplet transmission nor pollutant transmission seems to have been fully verified; however, among the many super-spreading incidents observed, infections occurred indoors more often than outdoors. A group of research teams from Taiwan, the United States, and Israel are eager to understand the spread of the COVID-19 virus and other respiratory viruses.

Therefore, they reviewed and analyzed many super-transmission events during the spread of the COVID-19 epidemic, and they finally discovered The same conclusion was reached: transmission through the air is the most likely way of transmission of the new coronavirus, rather than the way previously thought to be transmitted by contact with pollutant surfaces or droplets.

Many of these unfortunate infections are caused by exposure to a virus-contaminated environment for an hour or more, poor ventilation in the house, not wearing a mask to protect against the virus, or not wearing a mask properly.

The researchers also analyzed data collected from many other types of research-air sampling, polymerase chain reaction (PCR)-based research and cell culture research, epidemiological analysis, laboratory and clinical research and modeling research, In the end, they concluded that the airborne transmission of these new coronaviruses is the main route, and even most other respiratory viruses are mainly transmitted through the air. Airborne transmission is not limited to the new coronavirus.

For a long time, people have not fully realized that viruses can also be spread by inhaling virus-carrying aerosols. Wang Jiachang, director of the Aerosol Science Research Center at National Sun Yat-sen University in Taiwan and an aerosol physical chemist, took the lead in expressing this conclusion. He said: “It is time to change the traditional virus protection model by implementing aerosol preventive measures, which can be more effective. To protect the public from the effects of the virus through this method of transmission.”

The research team pointed out that the prevalence of the spread of respiratory diseases can be traced back to a century ago. At the beginning of the 20th century, Charles Chapin, a famous public health figure, dismissed airborne transmission. He was worried that people would be scared to take no action when talking about airborne transmission, and would replace hygiene habits. An unproven hypothesis mistakenly equates close-range infection with droplet transmission, forming the current paradigm for controlling the spread of respiratory viruses. However, Kim Prather said: “This assumption ignores the fact that aerosol transmission also occurs at short distances, because the closer a person is to an infected person who releases the aerosol, the higher the aerosol concentration he exhales. “Kim Prather is the director of the National Science Foundation Center for the Effects of Aerosols on Environmental Chemistry at the Scripps Institute of Oceanography at the University of California, San Diego, and the aerosol chemist who led the research.

Breathing aerosols are formed by exhalation activities, such as breathing, talking, singing, shouting, coughing and sneezing. Before the outbreak of the COVID-19 in 2019, the traditional size boundary between smoke-like aerosols and droplets was set to 5μm, and 100μm is a more suitable size boundary. The updated size better represents the largest particles that can be suspended in still air for more than 5 seconds (from a height of 1.5 meters) and more than 1 meter away from the infected person and be inhaled. Josué Sznitman, a pulmonary physiologist at Technion in Israel, explained: “Their size mainly determines how long they can be suspended in the air, how far they can fly, whether they can be inhaled, and how deep they can enter the respiratory tract after being inhaled. Respiratory activity Most of the aerosols produced are smaller than 5 μm, which allows them to penetrate deep into the bronchioles and alveolar areas and deposit there. Studies have found that the virus is more abundant in aerosols smaller than 5 μm.”

Another characteristic of aerosols that deserves serious consideration is their ability to be affected by airflow and ventilation. Ensuring adequate ventilation rates, filtering, and avoiding recirculation can help reduce the airborne transmission of aerosols that carry infectious viruses. Jose-Luis Jimenez, an atmospheric aerosol chemist at the University of Colorado Boulder, added: “The use of portable meters to monitor carbon dioxide helps to verify adequate ventilation. The use of portable high-efficiency particulate air purifiers and upper room UV disinfection systems also help to reduce Concentration of aerosols that carry the virus.” On the other hand, Linsey Marr of Virginia Tech said: “The plexiglass barrier that is usually used to block droplets from indoor coughs and sneezes may “impede proper ventilation and expose some people to Higher in the air. “Marr has been studying the airborne transmission of pathogens for many years. He found that it is better to use a mask to defend against viruses, and its protective ability is still stronger, because the mask helps to remove aerosols, and the barrier just transfers them. Is an essential difference.”

With the surge in infections caused by the delta variant and the increase in “COVID-19 breakthrough cases” (infections in fully vaccinated populations), many governments and national disease control agencies have resumed the strategy of generally wearing masks in public. Using a mask to protect yourself from virus infection is an effective way to block the virus-carrying aerosol from invading the human body. However, Seema S. Lakdawala, a virologist at the University of Pittsburgh, added: “We need to consider a variety of methods to block the spread of the virus, such as: vaccination, wearing a mask and regular ventilation can effectively block the further spread of the virus. If only used A single strategy is unlikely to play a strong role, and these multiple methods are sufficient to stop the further spread of the newly emerging mutant new coronavirus.”

As more and more cases of COVID-19 infections are caused by the spread of the virus through the air, this approach and theory of air transmission has become particularly convincing, and various research institutions have already noticed the spread of COVID-19. This feature. In April and May 2021, the World Health Organization and the US Centers for Disease Control and Prevention admitted that inhaling virus-carrying aerosols is the main way for the new coronavirus to spread in short and long distances. This means that in order to slow down the wanton spread of the COVID-19 virus, all parts of the world should consider implementing preventive measures related to aerosols, including: encouraging residents to generally wear masks, paying attention to wearing masks with high protective effectiveness, and increasing the ventilation rate of indoor spaces. , To avoid the recirculation of polluted indoor air, install air filtration devices (install high-efficiency air particulate filters, this equipment can effectively remove particles in the air), you can also install ultraviolet disinfection lamps and so on.

This pandemic strongly illustrates the extent to which the long-underestimated virus can be spread through the air, and the need to protect people’s right to breathe clean and pathogen-free air. The lessons we have learned from this pandemic will also help us to adjust and change our attitude towards epidemics that may break out at any time, and also point out the way for the people of the world in the post-epidemic era to deal with the epidemic. Aerosol preventive measures will not only help prevent the airborne transmission of respiratory diseases, but will also improve indoor air quality, which will bring many benefits to our health.

(source:internet, reference only)


Disclaimer of medicaltrend.org