Covid-19 – The truth about facial masks, are useful or not?

by Giuseppe Scarlata, Antonino Napoleone, Domenico Gangemi | April 8, 2020

On 5th April 2020, the Italian Federation of Medical Doctors and Dentists (FNOMCeO) and Nursing Professions (Fnopi) reported the deaths of 80 doctors and 25 nurses, all infected while fighting in Italian hospitals to treat patients suffering from Coronavirus Disease-19 (Covid-19). The only strategies available at the moment to control the virus outbreak include the implementation of precautionary measures aimed at reducing its spread among the population. One of the main disputed matters of the current pandemic is related to the use of personal protective equipment (PPE), more in detail, face masks. When should a face mask be worn and how can it be chosen effectively?

Surgical masks: the most common of the PPE, it is able to retain droplets of saliva that represent the main vehicle of transmission of SARS-Cov-2, limiting its spread in the environment. They are not able to filter the air and consequently the virus. Therefore, they must be worn by individuals with symptoms of infection in order to protect others from possible infection.

FFP2 and FFP3 masks: they are able to filter inhaled and exhaled air with the primary function of protecting the wearer from external pathogens. Therefore they are particularly useful in environments in contact with infected patients, like Covid-19 intensive care units. Their full filtering capacity has limited duration if the mask is worn correctly and after following a suitable tightness test.

Homemade masks: the poor availability of official masks has led many people to resort to doing home remedies. Such solutions do not guarantee any air or virus filtering capacity, as they do not have the standard filtering technology (UNI EN 14683:2019) typical of FFP2 and FFP3 masks. However, they can emulate the function of surgical masks in order to retain the droplets of saliva, containing their diffusion in the environment.

The World Health Organization (WHO) recommends wearing a mask if there is any suspicion of being infected by the virus with symptoms such as coughing or sneezing, or if individuals are taking care of a patient who is currently infected. At the local level, several preventive measures regarding the use of PPE are being evaluated, including the extensive use of masks among the population in public environments. The situation changes completely in a healthcare setting. WHO guidelines are pretty clear: healthcare professionals in contact with a confirmed or suspected Covid-19 case should wear surgical masks, while in the case of frontline procedures where aerosols with high viral load are generated, FFP2/FFP3 facial respirators must be worn, along with all related PPE (gloves, long sleeve waterproof gown, protective cover, and goggles). Since the dimensions of SARS-CoV-2 are in the range of 100-160 nm, the use of FFP2/FFP3 is motivated by the fact that these filters can block 94-99% of the particles in the air up to a size of 0.6 µm. There are also available FFP1 masks (commonly known as “dust-masks”) that block less than 80% of airborne particles, making them unsuitable for working in a healthcare environment. On the other hand, infected or potentially infected individuals need to wear a surgical mask to retain the droplets of saliva (about 0.5-5 µm in size) and consequently limit the spread of the virus in the environment. The main warning is obviously to promote the correct use of these systems of individual protection by explaining and sharing official and correct information in order not to unnecessarily deplete resources that could instead be allocated and made available to health care workers who are running out of energies and equipment. This is why the European Centre for Disease Prevention and Control (ECDC) in Stockholm has drawn up a table with the estimated daily need for personal protective equipment by medical doctors and healthcare workers in contact with Covid-19 patients, to whom more of such equipment must be allocated than the general population. Medical doctors and healthcare workers on the frontline of the coronavirus outbreak must be protected and put in the most suitable and safest conditions to carry out their work. Do not underestimate their importance, which unfortunately today may result in their absence. Share and have faith in medical sciences rather than the media, we all need to work together to stop all of this.

References:

1. Rational use of personal protective equipment for coronavirus disease 2019 (COVID-19) – World Health Organization – 27 February 2020.
2. https://doi.org/10.1016/S2213-2600(20)30134-X
3. https://doi.org/10.1089/jam.2007.0610
4. https://doi.org/10.1016/j.ijnurstu.2020.103567
5. Personal protective equipment (PPE) needs in healthcare settings for the care of patients with suspected or confirmed novel coronavirus (2019-nCoV) – ECDC technical report – February 2020.