A study carried out by researchers from Bangladesh and the University of Yale, in the United States, proved the effectiveness of masks in combating Covid-19. The survey, carried out through a randomized clinical trial, was published in pre-print and is being reviewed by the scientific community to be made available in the journal Science.
Between November 2020 and April 2021, researchers studied the use of masks in 600 villages in Bangladesh, with 342,000 adults — the study is considered the largest so far on the use of the protective item.
Among the participants, 178,000 received tissue and surgical masks free of charge. They were also informed about the importance of the equipment and reminded of it every eight weeks. Group leaders wore masks all the time to set an example. The other group received no intervention.
Researchers observed communities weekly to understand which groups actually wore the masks and sought to distance themselves in clusters. In weeks five and nine of the study, all participants underwent Covid tests. At weeks 10 and 12, blood samples were collected for antibody testing.
The interventions – free distribution and information – tripled the correct use of the mask, with 13.3% in the group that received nothing against 42.3%. Social distancing was 24.1% among participants in the control group and 29.2% among those who received guidance.
About five months after the interventions, the impact diminished, and people stopped using the protective equipment – however, the group that received the masks continued using the item 10% more than other people.
Among those who were supported, 7.6% had Covid, compared to 8.6% in the control group. The researchers say the interventions decreased symptomatic Covid-19 cases by 9.3%. Symptomatic infections were also 11.2% lower among people who wore surgical masks instead of cloth.
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