STOCKHOLM, Aug. 3 (Xinhua) -- Researchers from Karolinska Institutet (KI) in Sweden on Monday recommended the use of face masks to contain the COVID-19 pandemic, as their latest findings showed that cloth face masks can reduce the spread of the coronavirus that causes COVID-19.
Sweden has so far counted 5,744 deaths and 81,012 infections in a population of over 10 million. Despite that, Sweden has neither imposed a lockdown -- even during the peak of the pandemic -- nor asked people to wear masks in public, quoting a lack of support in research.
Literature review coordinated by KI and McMaster University in Canada demonstrated that cloth face masks provide clinically useful levels of filtration, which has the potential to reduce the spread of viruses such as SARS-CoV-2, a press release from KI said.
"This evidence should be more than sufficient to recommend their use, particularly given the difficulty in controlling the ongoing pandemic," Juan-Jesus Carrero, professor of epidemiology at the Department of Medical Epidemiology and Biostatistics, KI, was quoted as saying.
The research group identified 25 published articles that studied the filtration properties of cloth or cloth face masks of various designs and materials, and the results "convincingly demonstrate that certain cloth face masks reduce the spread of particles to the wearer's surroundings and reduce the particles inhaled."
"Even single layers block some particles and multiple layers perform better," said Carrero. "In our judgment, the use of face masks should be a key component of reducing the spread of COVID-19, which is in line with current recommendations from the WHO and the CDC in the United States."
Moreover, the materials demonstrated to offer the best protection were muslin, cotton and flannel, preferably in three to four layers and with a thread count of at least 100 threads per inch (TPI), the researchers said.
The findings have been published in the journal Mayo Clinic Proceedings.