Authors: Michaël Rochoy (@mimiryudo), Jonathan Favre (@DrJohnFa) and Thibault Puszkarek (@puszkarek) are general practitioners, ex-chief residents of the university of Lille (@univ_lille @medecine_Ulille). Together with Antoine Hutt, a radiologist specialising in thoracic imaging at Lille University Hospital (@CHU_Lille), they rationalise and encourage the use of anti-postillation screens in France on the website https://stop-postillons.fr (@SPostillons).

With fewer than 8,000 cases and fewer than 200 deaths, the French government decreed the confinement of the population from 17 March 2020. This confinement leaves the possibility to go out (work, urgent care, shopping, to help a dependent relative, for short physical activity) but during these outings, very few people wear masks.

We do not wear a mask to protect ourselves, but we all wear a screen to protect others.

In February, France had a stock of about 100 million surgical single-use masks and no N95 masks. Current needs are estimated at 50 million masks per week to cover the needs of the 67 million inhabitants. Aware of this international shortage of masks, individual or collective initiatives for the manufacture of “anti-postillation screens” have emerged: home-made masks, plastic screens, etc. These screens are not intended for use by caregivers and should not be recommended for use by them. They are intended to replace surgical masks for the general public in a context of shortage; their objective is the same as that of the surgeon in the operating room: to avoid contaminating the environment. This is a paradigm shift adopted by many countries: we do not wear a mask to protect ourselves, but we all wear a screen to protect others.

This idea is supported by four studies from 2008 to 2020, showing the effectiveness of a home-made anti-postillation screens, using a tea towel, T-shirt or cotton.(1–4) These screens protect the environment and are better than nothing, in cases of surgical or N95 masks shortages. Using home-made screens allows certified masks to be reserved for caregivers, and generalised wearing of masks does not lead to stigmatisation, contrary to sporadic wearing.

While the anti-postillation screen can protect the environment when worn collectively, it can also protect the wearer by three mechanisms: a filtering effect (1,2) the limitation of manuportage (hand-to-mouth contact), and the social distancing favoured by wearing the screen. On the basis of these arguments, the precautionary principle would suggest that the wearing of anti-postillation screens should be generalised, as the sixth barrier measure in France, given the possibly significant impact on transmission, compared to the low impact on social and economic life.(5)

The 1918 pandemic feedback showed that early public health measures work best.

But, as these screens are not certified, the French government never refers to them as a barrier measure. On the contrary, some political figures refer to “the uselessness”, “the ignorance about how to wear it properly”, “the poor hand washing due to wearing a mask”, “the risk of not respecting the social distance”, etc. These arguments do not support the reality, since alcohol sanitiser gel/fluid is missing, and intervals between supermarket shelves rarely exceeds one metre. Widespread-wearing of masks seems to be postponed until 11th May, when we can ensure the production of validated masks for workers, and then for general public… too late! The 1918 pandemic feedback showed that early public health measures work best, and there was no question of administrative certification at that time.(6)

Finally, the coronavirus pandemic always seems to be ahead. Several countries or regions have made the wearing of face masks mandatory in the public space: Czech Republic (19 March), Austria, Slovenia (31 March), Lombardy, Slovakia (4 April), Canada (6 April), Luxembourg (8 April), Morocco (9 April), Portugal (13 April), Poland (16 April), Saxony (17 April). The US Centers for Disease Control and Prevention (CDC) has been recommending this generalised measure since 3 April; their European counterpart issued the same opinion on 8 April. This measure must be generalised, piloted by the governments. Yet today there is a continued delay for some countries in making a decision on masked containment.

 

References

1. van der Sande M, Teunis P, Sabel R. Professional and home-made face masks reduce exposure to respiratory infections among the general population. PLoS ONE 2008;3(7):e2618.
2. Davies A, Thompson K-A, Giri K, Kafatos G, Walker J, Bennett A. Testing the efficacy of homemade masks: would they protect in an influenza pandemic? Disaster Med Public Health Prep 2013;7(4):413–8.
3. Bae S, Kim M-C, Kim JY, et al. Effectiveness of Surgical and Cotton Masks in Blocking SARS–CoV-2: A Controlled Comparison in 4 Patients. Ann Intern Med [Internet] 2020 [cited 2020 Apr 8]. Available from: https://annals.org/aim/fullarticle/2764367/effectiveness-surgical-cotton-masks-blocking-sars-cov-2-controlled-comparison
4. Ma Q-X, Shan H, Zhang H-L, Li G-M, Yang R-M, Chen J-M. Potential utilities of mask wearing and instant hand hygiene for fighting SARS-CoV-2. J Med Virol 2020;
5. Greenhalgh T, Schmid MB, Czypionka T, Bassler D, Gruer L. Face masks for the public during the covid-19 crisis. BMJ [Internet] 2020 [cited 2020 Apr 10];369. Available from: https://www.bmj.com/content/369/bmj.m1435
6. Bootsma MCJ, Ferguson NM. The effect of public health measures on the 1918 influenza pandemic in U.S. cities. Proc Natl Acad Sci USA 2007;104(18):7588–93.

 

Featured photo by engin akyurt on Unsplash