According to the World Health Organization (WHO), Coronavirus disease 2019 (COVID-19), caused by the COVID-19 virus, was first detected in Wuhan, China, in December 2019. On Thursday, January 30, 2020, the WHO Director-General declared that the current outbreak constituted a public health emergency of international concern.
The World Health Organization on Thursday, February 27, 2020 published a document summarizing WHO’s recommendations for the rational use of personal protective equipment (PPE) in healthcare and community settings, as well as during the handling of cargo. In this context, PPE includes gloves, medical masks, respirators (i.e., N95 or FFP2 standard or equivalent for specific procedures), goggles or a face shield, gowns, and aprons. The document is intended for those who are involved in distributing and managing PPE, as well as public health authorities and individuals in healthcare and community settings, and it aims to provide information about when PPE use is most appropriate.
WHO reports the organization will continue to update these recommendations as new information becomes available.
People Confuse ‘Airborne’
Two main routes of infections are possible for routes of transmission categorized by the size of the particle. Sometimes experts say a disease organism isn’t transmitted airborne because they’re referring to Droplet Infections as opposed to Airborne Infections. However Droplet Infections can be airborne for a short period of time.
Airborne Infections usually occur by the respiratory route, with the infectious agent or infectious particles (<5 µm in diameter) present in aerosols that stay in the air for a prolonged period of time (months). Airborne includes dry particles, often the remainders of an evaporated wet particle called nuclei, and wet particles. This kind of infection usually requires independent ventilation to prevent transmission. Tuberculosis is an example of an illness with an infectious agent with a transmission route that might occur in air from room to room via ventilation ducts with survivability of months on surfaces.
Droplet Infections involve large droplets (>5 µm in diameter) that carry the infectious agent. The droplets may be airborne, but they will drop to the ground, floor or other surfaces in a shorter period of time. Transmission usually involves wet particles and is considered to be direct exposure to the droplets that usually occurs in the presence of the infected individual. The common cold is an example of an illness with a transmission route that can infect via droplets, such as inhaling mist from a recent sneeze or when eyes come into contact with mist from a recent sneeze.
Other common transmission can occur by direct physical contact or indirect physical contact. For example, an infectious agent in a sneeze can land on a door knob, and the infectious agent can remain viable on the door knob for a period of time. An unsuspecting person can touch the door knob and then touch their eyes or nose and become infected. As of late February 2020 there were no specific survivability reports for the COVID-19 virus, but the Centers for Disease Control (CDC) states because of poor survivability of coronaviruses on surfaces, there is likely very low risk of spread from products or packaging that are shipped over a period of days or weeks at ambient temperatures. A study in 1985 of human coronavirus survival found that high relative humidity (RH) and low temperature increased the survivability of airborne human coronavirus. On surfaces, a study using virus surrogates found that viruses were inactivated more quickly at higher temperatures than lower temperatures, and were inactivated more quickly at moderate relative humidity (50%) compared to relative humidity at RH (20%) or RH (80%).
Preventive measures for COVID-19 disease
Based on the available evidence, the COVID-19 virus is transmitted between people through close contact and droplets, not by airborne transmission. The people most at risk of infection are those who are in close contact with a COVID-19 patient or who care for COVID-19 patients. Preventive and mitigation measures are key in both healthcare and community settings. The most effective preventive measures in the community include:
• performing hand hygiene frequently with an alcohol-based hand rub if your hands are not visibly dirty or with soap and water if hands are dirty;
• avoiding touching your eyes, nose and mouth;
• practicing respiratory hygiene by coughing or sneezing into a bent elbow or tissue and then immediately disposing of the tissue;
• wearing a medical mask if you have respiratory symptoms and performing hand hygiene after disposing of the mask;
• maintaining social distance (a minimum of 1 m or 3.3 feet) from individuals with respiratory symptoms. Note: local paramedics are being advised stay 6 feet away from any possible coronavirus patients until properly dressed in PPE.
Additional precautions are required by healthcare workers to protect themselves and prevent transmission in the healthcare setting. Precautions to be implemented by healthcare workers caring for patients with COVID-19 disease include using PPE appropriately; this involves selecting the proper PPE and being trained in how to put on, remove and dispose of it.
PPE is only one effective measure within a package that comprises administrative and environmental and engineering controls, as described in WHO’s Infection prevention and control of epidemic- and pandemic-prone acute respiratory infections in health care. These controls are summarized here.
• Administrative controls include ensuring the availability of resources for infection prevention and control measures, such as appropriate infrastructure, the development of clear infection prevention and control policies, facilitated access to laboratory testing, appropriate triage and placement of patients, adequate staff-to-patient ratios and training of staff.
• Environmental and engineering controls aim at reducing the spread of pathogens and reducing the contamination of surfaces and inanimate objects. They include providing adequate space to allow social distance of at least 1 m to be maintained between patients and between patients and healthcare workers and ensuring the availability of well-ventilated isolation rooms for patients with suspected or confirmed COVID-19 disease.
COVID-19 is a respiratory disease that is different from Ebola virus disease, which is transmitted through infected bodily fluids. Due to these differences in transmission, the PPE requirements for COVID-19 are different from those required for Ebola virus disease. Specifically, coveralls (sometimes called Ebola PPE) are not required when managing COVID-19 patients.
Disruptions in the global supply chain of PPE
The current global stockpile of PPE is insufficient, particularly for medical masks and respirators; the supply of gowns and goggles is soon expected to be insufficient also. Surging global demand − driven not only by the number of COVID-19 cases but also by misinformation, panic buying and stockpiling − will result in further shortages of PPE globally. The capacity to expand PPE production is limited, and the current demand for respirators and masks cannot be met, especially if the widespread, inappropriate use of PPE continues.
Recommendations for optimizing the availability and need for PPE
Minimizing the need for PPE …
Health care providers and facilities are being advised to minimize the need to use PPE and to ensure that PPE is actually necessary.
• consider using telemedicine to evaluate suspected patient remotely to minimize the need for individuals to go to a healthcare facility for evaluation.
• use physical barriers, such as glass or plastic windows in triage areas, registration desks at the emergency department, or at pharmacy windows to minimize exposure of individuals.
• deliver food by healthcare workers while they are wearing PPE and involved in other direct care of the patients — so-called bundling of activities while wearing PPE.
Restricting visitors may also be necessary because of lack of available PPE.
Ensuring PPE is actually needed and being used appropriately …
PPE should be used based on the risk of exposure (e.g., type of activity) and the transmission dynamics of the pathogen (e.g., contact, droplet or aerosol). The overuse of PPE will have a further impact on supply shortages. Observing the following recommendations will ensure that the use of PPE rationalized …
• The type of PPE used when caring for COVID-19 patients will vary according to the setting and type of personnel and activity.
• Healthcare workers involved in the direct care of patients should use the following PPE: gowns, gloves, medical mask and eye protection (goggles or face shield).
• Specifically, for aerosol-generating procedures (e.g., tracheal intubation, non-invasive ventilation, tracheostomy, cardiopulmonary resuscitation, manual ventilation before intubation, bronchoscopy) healthcare workers should use respirators, eye protection, gloves and gowns; aprons should also be used if gowns are not fluid resistant.
• Respirators (e.g., N95, FFP2 or equivalent standard) have been used for an extended time during previous public health emergencies involving acute respiratory illness when PPE was in short supply. This refers to wearing the same respirator while caring for multiple patients who have the same diagnosis without removing it, and evidence indicates that respirators maintain their protection when used for extended periods. However, using one respirator for longer than 4 hours can lead to discomfort and should be avoided.
• Among the general public, persons with respiratory symptoms or those caring for COVID-19 patients at home should receive medical masks. For additional information, see Home care for patients with suspected novel coronavirus (COVID-19) infection presenting with mild symptoms, and management of their contacts.
• For asymptomatic individuals, wearing a mask of any type is not recommended. Wearing medical masks when they are not indicated may cause unnecessary cost and a procurement burden and create a false sense of security that can lead to the neglect of other essential preventive measures.
Coordinating PPE supply chain management mechanisms …
WHO also provided certain supply chain management recommendations to prevent duplication, waste and overstock. See the WHO document [PDF] for additional information.
Handling cargo from countries affected by COVID-19
The rationalized use and distribution of PPE when handling cargo from and to countries affected by the COVID-19 outbreak includes following these recommendations.
Wearing a mask of any type is not recommended when handling cargo from an affected country.
Gloves are not required unless they are used for protection against mechanical hazards, such as may occur when manipulating rough surfaces.
WHO noted, the use of gloves does not replace the need for appropriate hand hygiene, which should be performed frequently, as described above.
When disinfecting supplies or pallets, no additional PPE is required beyond what is routinely recommended. To date, there is no epidemiological information to suggest that contact with goods or products shipped from countries affected by the COVID-19 outbreak have been the source of COVID-19 disease in humans.
WHO is advising that the organization will continue to closely monitor the evolution of the COVID-19 outbreak and will update recommendations as needed.
See also …
Casanova LM, Jeon S, Rutala WA, Weber DJ, Sobsey MD. Effects of air temperature and relative humidity on coronavirus survival on surfaces. Appl Environ Microbiol. 2010;76(9):2712–2717. doi:10.1128/AEM.02291-09
Ijaz MK, Brunner AH, Sattar SA, Nair RC, Johnson-Lussenburg CM. Survival characteristics of airborne human coronavirus 229E. J Gen Virol. 1985;66 ( Pt 12):2743–2748. doi:10.1099/0022-1317-66-12-2743
Kramer A, Schwebke I, Kampf G. How long do nosocomial pathogens persist on inanimate surfaces? A systematic review. BMC Infect Dis. 2006;6:130. Published 2006 Aug 16. doi:10.1186/1471-2334-6-130
Allen BW. Excretion of viable tubercle bacilli by Blatta orientalis (the oriental cockroach) following ingestion of heat-fixed sputum smears: a laboratory investigation. Trans R Soc Trop Med Hyg. 1987;81(1):98–99. doi:10.1016/0035-9203(87)90295-1