A study conducted by research teams in Texas and California found that the best way to prevent person-to-person spread of COVID-19 is by wearing a face mask.
The coronavirus spreads through airborne transmission of respiratory droplets called aerosols. The World Health Organisation explains that coronavirus can also spread through direct contact such as coughing, speaking or sneezing on another person. Indirect contact is another form of transmission. This is when an infected person coughs or sneezes on an object that is then touched by another person.
According to CNN, the research teams compared the rate of coronavirus infection in New York, Wuhan and Italy before and after masks were made compulsory.
The research team analysed trends in the infection rates in Wuhan, New York and Italy to determine the main method of transmission. They also analysed the measures in place in these three locations to combat the spread of the virus. These include quarantining, social distancing, contact tracing, extensive testing and compulsory use of face masks.
Following the mandatory implementation of wearing face masks in public, the three locations experienced a reduced rate of infection, the study found.
According to the research team: “This protective measure alone significantly reduced the number of infections, that is, by over 78,000 in Italy from April 6 to May 9 and over 66,000 in New York City from April 17 to May 9.” The coronavirus was declared a global pandemic on March 11, 2020.
“The curve flattening in China can be attributed to extensive testing, quarantine, and contact tracing; other aggressive measures implemented in China include lockdown of all cities and rural areas in the whole country, isolation of residents having close contact with infected people, and mandated wearing of face masks in public.”
The timing of when these measures were implemented was also compared. China implemented all preventative measures at the same time. Italy and New York, however, did not and were staggered.
This difference allowed the team to analyse the effectiveness of the mitigation methods relative to each location. In Italy and New York, the rate of infection only began to slow once masks were made compulsory.
“To gain insight into the mechanism of the virus transmission routes and assess the effectiveness of mitigation measures, we analyzed the trend of the pandemic worldwide from January 23 to May 9, 2020,” wrote the research team.
“The COVID-19 outbreak initially emerged during December 2019 in Wuhan, China. The numbers of confirmed infections and fatalities in China dominated the global trend during January and February 2020, but the increases in the newly confirmed cases and fatalities in China have exhibited sharp declines since February. In contrast to the curve flattening in China, those numbers in other countries have increased sharply since the beginning of March.
“The epicenter shifted from Wuhan to Italy in early March and to New York City (NYC) in early April. By April 30, the numbers of confirmed COVID-19 cases and deaths, respectively, reached over 200 000 and 27 000 in Italy and over 1 000 000 and 52 000 in the United States, compared to about 84 000 and 4600 in China.”
“We conclude that wearing of face masks in public corresponds to the most effective means to prevent inter-human transmission, and this inexpensive practice, in conjunction with simultaneous social distancing, quarantine, and contact tracing, represents the most likely fighting opportunity to stop the COVID-19 pandemic.”
The study, titled Identifying airborne transmission as the dominant route for the spread of COVID-19 is published in the Proceedings of the National Academy of Sciences of the United States of America and can be read in full here.
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