Merci pour le lien, j'ai fait une liste des études les plus notables avec citation des passages les plus intéressants.
Il en manque sûrement mais ca donne une bonne idée du truc.
J'ai été surpris d'apprendre qu'il n'y a même pas de preuves tangible que les masques chirurgicaux protègent efficacement des infections opératoires quand porté par les chirurgiens.
En fait on sait très peu de choses sur la manière dont les virus se propagent, tout le domaine de la virologie repose sur des fondements très bancals.
WHO Admits: No Direct Evidence Masks Prevent Viral Infection.
While masks do not prevent the spread of viral infections, the WHO still makes a case for universal mask-wearing, citing benefits such as reduced stigmatization of people caring for COVID-19 patients in nonclinical settings, making people feel like they’re doing something to help, serving as a reminder to be compliant with other measures, economic benefits for people who can sew homemade masks and evaluate the impact (positive, neutral or negative) of using masks in the general population (including behavioral and social sciences).
The author has shown that wearing face masks by the public outside of hospital/nursing settings is useless as source control for COVID-19. When mandated, it becomes harmful .
Goldstein L. Does Universal Mask Wearing Decrease or Increase the Spread of COVID-19? Watts Up With That? 2020. https://wattsupwiththat.com/2020/07/25/does-universal-mask-wearing-decrease-or-increase-the-spread-of-covid-19/
(accessed August 11, 2020).
Other research has shown that wearing masks by the public in general settings is not effective against the spread of a respiratory epidemic : “During the 2009 pandemic of H1N1 influenza (swine flu), encouraging the public to wash their hands reduced the incidence of infection significantly whereas wearing facemasks did not”
Isaacs D, Britton P, Howard‐Jones A, Kesson A, Khatami A, Marais B, et al. Do facemasks protect against COVID‐19? J Paediatr Child Health 2020;56:976–7. https://doi.org/10.1111/jpc.14936.
A 2017 systematic review and meta-analysis found similarly even for surgical masks : “Facemask use provided a non-significant protective effect.”
Saunders-Hastings P, Crispo JAG, Sikora L, Krewski D. Effectiveness of personal protective measures in reducing pandemic influenza transmission: A systematic review and meta-analysis. Epidemics 2017;20:1–20. https://doi.org/10.1016/j.epidem.2017.04.003
(Howard #16) is a 2020 meta-review pre-print with the same lead author as. It found that “There was insufficient evidence to provide a recommendation on the use of facial barriers without other measures”, “Nine trials compared masks with no masks. … Pooling of all nine trials did not show a statistically significant reduction of ILI cases.” Two among of the nine trials were conducted on healthcare workers. Most of the trials were conducted with surgical masks or respirators.
Jefferson T, Jones M, Al Ansari LA, Bawazeer G, Beller E, Clark J, et al. Physical interventions to interrupt or reduce the spread of respiratory viruses. Part 1 – Face masks, eye protection and person distancing: systematic review and meta-analysis. MedRxiv 2020:2020.03.30.20047217. https://doi.org/10.1101/2020.03.30.20047217
Studies found that there is no evidences that wearing a mask during surgeries reduce the risks of infections.
“It would appear that minimum contamination can best be achieved by not wearing a mask at all” and that wearing a mask during surgery “is a standard procedure that could be abandoned.”
Among outpatient HCP, N95 respirators vs medical masks as worn by participants in this trial resulted in no significant difference in the incidence of laboratory-confirmed influenza.
Face mask use in health care workers has not been demonstrated to provide benefit in terms of cold symptoms or getting colds.
A 2015 study in the British Medical Journal BMJ Open found that cloth masks were penetrated by 97% of particles and may increase infection risk by retaining moisture or repeated use.
Moisture retention, reuse of cloth masks and poor filtration may result in increased risk of infection.
Respiratory pathogens on the outer surface of the used medical masks may result in self-contamination.
A May 2020 meta-study on pandemic influenza published by the US CDC found that face masks had no effect, neither as personal protective equipment nor as a source control.
A July 2020 review by the Oxford Centre for Evidence-Based Medince found that there is no evidence for the effectiveness of cloth masks against virus infection or transmission.
A Covid-19 cross-country study by the University of East Anglia found that a mask requirement was of no benefit and could even increase the risk of infection.
An April 2020 review by two US professors in respiratory and infectious disease from the University of Illinois concluded that face masks have no effect in everyday life, neither as self-protection nor to protect third parties (so-called source control).
An article in the New England Journal of Medicine from May 2020 came to the conclusion that cloth face masks offer little to no protection in everyday life.
An April 2020 review by the Norwich School of Medicine (preprint) found that “the evidence is not sufficiently strong to support widespread use of facemasks”, but supports the use of masks by “particularly vulnerable individuals when in transient higher risk situations.”
A July 2020 study by Japanese researchers found that cloth masks “offer zero protection against coronavirus” due to their large pore size and generally poor fit.
Risks associated with face masks
The WHO warns of various “side effects” such as difficulty breathing and skin rashes.
Tests conducted by the University Hospital of Leipzig in Germany have shown that face masks significantly reduce the resilience and performance of healthy persons.
A German psychological study with about 1000 participants found “severe psychosocial consequences” due to the introduction of mandatory face masks in Germany.
The Hamburg Environmental Institute warned of the inhalation of chlorine compounds in polyester masks as well as problems in connection with face mask disposal.
The European rapid alert system RAPEX has already recalled 70 mask models because they did not meet EU quality standards and could lead to “serious risks”.
In China, two boys who had to wear a mask during sports classes fainted and died.
In the US, a car driver wearing an N95 (FFP2) mask fainted and crashed into a pole.