Personal Protective Equipment (PPE) to Prevent the COVID-19. What Do Healthcare Workers Really Need to Protect Themselves and Survive?

Background: The healthcare workers are exposed to dangerous pathogen agents during the outbreak of the new coronavirus COVID-19. To minimize the risk of becoming infected by this virus, healthcare workers need to wear the most appropriate personal protective equipment (PPE). Objective: The objective of this study was to analyze the guidelines that the World Health Organization (WHO) and the Centers for the Disease Control and Prevention (CDC) recommend for the rational use of EPP to protect healthcare workers against the novel coronavirus COVID19. Methodology: To learn how to effectively protect healthcare workers against the COVID-19, a detailed analysis and comparison of the WHO and CDC guidelines related to the proper use of personal protection equipment (PPE) in different healthcare settings was carried out. Results: The results of this study based on an analysis of PPE recommended by the World Health Organization (WHO) and the Centers for the Disease Control and Prevention (CDC) indicated that the safety and protection of healthcare workers can be maximized if the guidelines Preprints (www.preprints.org) | NOT PEER-REVIEWED | Posted: 24 June 2020 doi:10.20944/preprints202006.0290.v1 © 2020 by the author(s). Distributed under a Creative Commons CC BY license. 2 suggested by these institutions are followed. In general, the WHO and CDC recommendations based on medical practices are similar, and depending on the healthcare activities and settings where the healthcare workers perform their work, suggest wearing medical/surgical facemasks, respirators, googles and face shields (eye protection), gloves, gowns and aprons. Conclusions: The protection and safety of the healthcare workers can be maximized during the outbreak of COVID-19 by following the WHO and CDC recommendations described in this study. The general guidelines offered by these institutions are similar and based on medical practices.


Introduction
The COVID -19 is a respiratory disease associated with the Severe Acute Respiratory Sindrome Coronavirus-2 (SARS-CoV-2). 1 The virus is transmitted from person to person through tiny droplets secreted when they speak, cough, sneeze, or interact with another person who is less than 1 meter away. 1 The virus-infected droplets can be directly inhaled by people or deposited on different surfaces. If people touch these contaminated surfaces, they can become infected with the virus if it reaches their mouth, nose, or eyes. 1 The virus can stay alive on different surfaces from several hours to a few days, and the estimated period for incubation of the virus is between 1 and 14 days. 1 To avoid being infected by this virus, it is necessary not to touch your face with unwashed hands, since the virus penetrates through the mouth, nose and eyes. Hands should be washed with soap and water for at least 20 seconds. 1 In addition, alcohol-based disinfectants can be used. Another rule of caution is to stay more than 1 meter away from people infected with the Covid-19 virus. Although there are some asymptomatic persons, most of people infected with the Covid-19 can present various symptoms such as sore throat, cough, fever, muscle pain, general weakness, pneumonia, acute respiratory distress, septic shock, multi-organ failure, and other symptoms that can cause death. 1 The universal COVID-19 pandemic is evolving rapidly and has caused many deaths in different countries of the world. 2 For this reason, most health organizations worldwide make numerous efforts to stop the spread of the COVID-19. In this process, healthcare workers play an important role and must take all possible protective measures to protect themselves and prevent the spread of the virus in healthcare settings. In this sense, the use of personal protective equipment (PPE) is the most visible and obvious control to prevent the propagation of  According to the World Health Organization (WHO) "the protection of health workers is paramount and PPE, including medical masks, respirators, gloves, gowns, and eye protection, must be prioritized for health care workers and others caring for COVID-19 patients. 3 Based on these comments, the main objective of this study was to analyze the guidelines that the World Health Organization (WHO) and the Centers for the Disease Control and Prevention (CDC) recommend for the rational use of EPP to protect healthcare workers against the COVID-19 virus.

Medical/surgical facemasks
Medical / surgical facemasks are designed to protect the face (mouth and nose) against droplets, splashes and sprays that may contain respiratory pathogens /CONAVID-19. 5 They are devices that create a physical barrier between the user's face and possible infection agents located in the nearby surroundings. Also, the masks can prevent exposure of saliva and respiratory emissions to others. In general, medical/surgical masks are regularly used for protection against the spread of droplets from respiratory infections that fall to the ground within a short distance range (less than 1 meter). 5 The surgical masks should not be worn for more than 6 hours of continuous use due to the risk of self-contamination by viral agents. 5 The masks are not reusable. 3, 4

Respirators
These devices reduce the risk that droplets contaminated with infectious agents enter the human body through the mouth and nose. 6 There are various types of respirators such as N95, FFP1, FFP2, and FFP3. 6 The filtration capacities of these respirators exceed those of common medical/surgical facemasks. 4 The N95 designation indicates that the respirator can block 95 % of liquid droplets or solid aerosol particles. 6 The terms FFP1, FFP2 and FFP3 designate filtering face piece (FFP) masks. 6 These masks have a high filtration capacity due to an electrostatic mechanism generated within a network of polypropylene fibers. Filtering capacity increases in the following order: FFP1, FFP2, and FFP3.The N95 has less filtration performance than the FFP2 respirator. 6 In general, respirators (N95, FFP1, FFP2, and FFP3) are utilized for pathogens agents smaller than common drops . 5 These airborne agents can remain suspended in the air for a long time. 5 The CDC recommends taking precautions when reusing respirators. 7,8 Until now, it is not known whether respirators can be reused effectively. 9 The WHO recommends using respirators for a maximum of 4 hours of continuous use. 10 Preprints (www.preprints.org) | NOT PEER-REVIEWED | Posted: 24 June 2020 doi:10.20944/preprints202006.0290.v1

Eyes protection: googles and face shields.
There are no specific guidelines to protect the eyes against pathogens of biological origin, such as the COVID-19. 1 However, the use of googles and face shields are recommended during any personal contact with suspected or infected people with respiratory agents / COVID-19. 3,4 These devices prevent drops, splashes and sprays from the nasal and oral secretions of people with respiratory infections / COVID-19 from entering the body of healthcare workers through the mucous membranes of the eyes. 12 The googles and face shields can be reused after cleaning and disinfecting properly. 4

Gloves
The gloves provide a physical barrier that prevents pathogen agents/COVID-19 from infecting the hands of healthcare workers. 13 Disposable non-sterile gloves can be used for caring of infected or suspected COVID-19 patients. 14 After use, the gloves should be throw out in a unlined garbage trash. They shouldn't be reused. 14

Gowns
The gowns are loose flowing garments that protect clothing of healthcare workers against droplets, sprays and splashes. Disposable gowns should be thrown away after use. However, cloth gowns should be washed, cleaned and disinfected after use. 3     The information given in Tables 1-4   In relation to the use of respirators, the CDC recommends to use N95 respirator in the following activities: 1) preliminary screening of patients affected by the COVID-19 (triage); 2) physical examination of patients with symptoms suggestive of COVID-19 (consultation room); 3)

Aprons
providing direct care to COVID-19 patients in absence of aerosol-generating procedures (patient room/ward); 4) providing direct care or assistance to COVID-19 patients at home. 4 The CDC suggests using the medical/surgical mask (called facemask by CDC) in all the cases mentioned above, if there are not available N95 respirators. 4 As an alternative, the WHO recommends wearing a medical / surgical mask in the activities described above, and when it is necessary to 1) The healthcare workers should use PPE according to the guidelines described in Table 1.
2) Whenever possible, to minimize the use of PPE, evaluation (preliminary screening and triage) of suspected cases of COVID-19 should be conducted in spaces with physical barriers such as plastic or glass windows. These barriers prevent direct contact between healthcare workers and suspected patients.
3) Similarly, the evaluation of suspicious cases can be done using m-Health technologies, telephones, and telemedicine systems to avoid that suspected patients go to the healthcare settings.
4) It is important to avoid misuse or inappropriate use of equipment. For example, using a higher level of respirator than it is required is a form of misuse of PPE. Another misuse is to use two gowns, three masks or double gloves, when you only need one piece of them. Finally, According to the WHO and CDC, if the healthcare workers follow the guidelines described in Table 1, the risks to be infected by the CONAVID-19 are minimized. 3,4

Conclusion
The protection and safety of the healthcare workers can be maximized during the COVID-19 outbreak of by following the WHO and CDC guidelines described in this study. In general, the WHO and CDC recommendations based on medical practices are similar, and depending on the healthcare activities and settings where the healthcare workers perform their work, suggest wearing medical/surgical facemasks, respirators, googles and face shields (eye protection), gloves, gowns and aprons.