Health officials in the canton of Graubünden studying a recent outbreak among staff at a hotel found a worrying trend – all of those who were infected wore plastic face shields, while those who avoided infection wore face masks.
Several employees of the hotel tested positive along with a guest.
Rudolf Leuthold, head of the cantonal health department in Graubünden, said the face shields were the common denominator in infections.
“It has been shown that only those employees who had plastic visors were infected. There was not a single infection among employees with a mask.”
Leuthold told Swiss news outlet 20 Minutes that a guest of the hotel was also infected: “We know that the guest was served by employees with plastic visors.”
Government warns against plastic face shields
On Tuesday, the cantonal health authorities in Graubünden spoke out against plastic face shields.
Cantonal doctor Marina Jamnicki said not only are plastic face shields less effective than face masks, they may provide wearers with a false sense of security.
Plastic face shields should be worn in tandem with a face mask, say cantonal authorities.
The Federal Office of Public Health agreed on Wednesday, pointing to increased infections among those who wear face shields.
Spokesman Yann Hulmann told 20 Minutes “the visors do not serve as an alternative to hygiene masks. Visors can be worn with masks to further enhance your own protection.”
The federal government is considering amending the rules for hospitality workers to require masks, although an announcement will only be made pursuant to a review.
Swiss officials in late July reiterated that plastic visors are no replacement for face masks in preventing the spread of the coronavirus.
Daniel Dauwalder, spokesperson for the Federal Office of Public Health, told The Local that the government's official position was that visors are “no substitute for face masks”.
“They protect the eyes from possible infection through droplets, but the possibility of infection via the nose or mouth cannot be excluded,” Dauwalder said.
“Visors only serve as a complementary form of protection measure in conjunction with a mask.”